A 
With Compliments of the Author. 
“ OBAL ELECTRICITY ill tin NEW DEPARTURE ” 
AN ESSAY 
BY 
HOP. TOPEAT T. HP. PATEICIP, 
READ BEFORE THE 
AMERICAN DENTAL ASSOCIATION, 
AT ITS 
TWENTIETH ANNUAL SESSION, 
Held in Boston on the 4th of August, 1880. 
BELLEVILLE: 
ADVOCATE STEAM PRINTING HOUSE. 
1881. “ORAL ELECTRICITY AND THE NEW DEPARTURE,” 
BY 
DR. JOHN J. R. PATRICK. 
IN questions of physics, or the laws governing material substances, 
mere opinion is often confounded with demonstration. I 
believe that most men are honest in their statements concerning their 
experience, their experiments, and their observations; but these 
must be capable of verification and demonstration, otherwise we 
should be in the condition of the man who resolved to regulate his 
watch by the town-clock, but would not inquire whether the town- 
clock was right or not. Outside of the known laws which govern 
the properties of matter, all becomes conjecture; and as there is no 
limit to the possible conjectures one may make regarding things 
beyond the power of demonstration, there can be no end to the dis- 
agreements that will arise if we permit ourselves to embark on this 
troubled sea of dignified guess-work. 
The materials used for filling teeth cannot be intelligently dis- 
cussed independently of the tooth-substance and its surroundings. 
Every element that enters into the composition of the living body, 
and every substance that is likely to come in contact with the material 
used for filling the teeth, the chemical affinity of the several substances 
present in the mouth, and the energy or force set free by molec- 
ular change, must all be considered before a scientific deduction can 
be established. 
Opinions and theories of men, based on their own experience and 
observation, especially when such experience relates to scientific 
matters or manipulative skill, include so many undecided questions, 
that it is not only unscientific, but dangerous, and even frivolous to 
hastily adopt them. The frequent failures in filling teeth with gold 
by the most conscientious operators—men who spare no pains to 
perform their work to the utmost of their ability — are too apt to 
lead them to seek the cause of failure outside of themselves ; for no 
man who honestly does his utmost is willing to suspect a lack of 
manipulative skill as the cause of his failure. No man feels com- 2 
posed under the imputation of a want of skill in his profession. If 
he is an imaginative man, he at once seeks redress and an explana- 
tion of his failures in a wilderness of speculation, in which there is 
no definite coherence. Hypothetic currents of electricity are mixed 
up with incompatibility of tooth-substance, chemical interaction and 
filling material. Imagination unconciously takes the place of rea- 
son, the inventive faculty is exercised in the interests of previous 
expectation, and emotional experiments are prosecuted with all the 
outward appearance of scientific accuracy—for scientific instruments 
are used (or rather abused) with automatic activity, regardless of 
the laws of exact association, and in the interests of the dominant 
idea. There are so many obscure phenomena connected with elec- 
tricity, so much of its action is undecided, and not reduced to law, 
that it offers superior inducements to persons of a marvelous tend- 
ency to revel in its mysteries, and to float in confident security, like 
the atoms of Epicurus, in a void. 
There are other causes that have been equally as fruitful as defec- 
tive manipulation in creating a belief in the superiority of plastic 
filling. 
1st. The continued appeals on the part of patients for inexpensive 
work. For instance, it is frequently the case that a well-dressed 
man, wearing diamond jewelry, will request his dentist to use the 
cheapest possible material ; and a majority of women will spend 
more money in one year with their milliners than they will with their 
dentists in ten years, and still feel the tax of the dentist the heavier 
of the two. 
2d. The ease of the patient and operator in the use of plastic 
materials. 
3d. The more profitable employment in a monetary point of view 
to the operator. 
4th. The deep interest shown by the champions and promulgators 
of this old system revived in putting compounds of their own manu- 
facture upon the market. 
Prof. J. Foster Flagg has given to the world his pamphlets on 
the “Basal Principles of the New Departure,” and declares that he 
is but the mouth-piece of Prof. Henry S. Chase and Dr. S. B. Palmer, 
and fully indorses the creed of these two gentlemen, that “The 
electro-chemical theory of the action of filling material and tooth- 
substance, and the incompatibility of gold with ‘Dentos,’ make gold 
the worst material to use for saving teeth.” 
Prof. Flagg further states in his pamphlet that with the assistance 
of Prof. Morton, of Hoboken; Prof Snyder, of Philadelphia ; 
Messrs. Eckfelt and Dubois, assayers of the Philadelphia Mint, to- 3 
gether with Drs. Palmer and Chase, dentists, he has “carefully and 
scientifically investigated, with the best instruments and apparatus 
the country has produced, every line of experiment which professed 
to show a current, which they believed to be eliminated by contact 
of metal with tooth bone, and found that such current had never 
been shown, much less measured.2’ So that Prof. Flagg falls back 
upon belief and his own acknowledged failures to preserve teeth 
wfith gold for the hypothesis of electric currents destroying tooth- 
bone when gold is employed in filling teeth. 
Prof. Flagg betrays the influence of some of the inducements I 
have enumerated for using plastic fillings in preference to gold, when 
he says that “teeth are safer in the hands of the majority of prac- 
titioners turned out from our schools with a plastic material for fill- 
ing than with gold.” This is a humiliating confession, and so much 
the worse for our professors and our schools ; for the dentist who 
cannot manipulate gold, either for plate or for filling, must take a 
back seat ; he has no business in the profession. Notwithstanding 
the failure to demonstrate the electric current, Dr. Flagg constantly 
refers his readers to the two dental electricians, Drs. Palmer and 
Chase, and informs us that letters by the score passed between Syr- 
acuse, St.Louis and Philadelphia on the subject, and that finally 
these three gentlemen were ready to promulgate the doctrines of 
the New Departure, or, more properly speaking, they were ready to 
present to the profession some new honey that they had abstracted 
from old hives. In reviewing the published experiments of Dr. 
Chase, which are indorsed by his co-laborers, I find them so full of 
fallacies, contradictions and misconstructions of physical law, that 
a few instances will suffice to render his whole line of experiments 
worthless. On pages 201 and 202 of the Missouri Dental Jour- 
nal. for the year 1876, the following sentences occur : 
“1st. The oral cavity may be compared in some sense to a single 
cell of a voltaic battery. 
“2d. Where the teeth are all soun-i and the oral fluids are in a 
perfectly physiological condition, the mouth is not a voltaic battery. 
“3d. There is probably more or less electricity evolved in the 
ordinary mouth nearly all the time, more especially if there is a 
tooth plugged with any metal whatever.” 
Here are three equivocal statements, if not contradictions. The 
first compares the mouth to a voltaic battery, the second denies it, 
and the third sustains the first proposition. 
On pages 202 and 203 the doctor states a well-established law in 
electro-metallurgy,—-that “The electric current passes from the pos- 
itive element to the negative one, and that element is positive which 4 
is most easily acted upon by the fluid in which the elements are 
immersed ; and that element is negative which is less -acted upon.” 
In other words, the positive element is that metal which is dissolved, 
and the negative element is that metal or substance upon which the 
metal is being deposited by the influence of the electric current, 
electricity simply being the carrier of the metal from the positive to 
the negative pole, as in the electrotype process. On the same page 
(203) the doctor says that dentos is a bad conductor of elec- 
tricity, and therefore it is a negative element in the oral battery.” 
I reply that a tooth is a good conductor of electricity, since it is 
permeated by the fluids of the tubuli. For proof of this assertion, 
grasp one of the poles of a battery and bring the other pole in con- 
tact with the teeth, which will readily determine this question. If 
“dentos” were a negative element in the “oral battery” and the 
filling material positive, by all the laws of electro-metallurgy the 
filling material would go to the “dentos” (the place where it usual- 
ly is needed), not the “dentos” to the filling material. In other 
words, the metal filling being positive must waste away and be car- 
ried by the current to the “dentos” and be deposited upon it either 
in the form of salts or of metal, and the dentine will remain intact. 
The whole of page 204 is devoted to contradicting his former 
statements, and to promulgating a few electrical impossibilities. 
One instance will suffice: “The electrical action between two sub- 
stances is none the less on account of the resistance offered to the 
passage of the current.” 
Now. it is a well-established fact among electro-metallurgists 
that the negative element is only considered as acting the part of a 
conductor, and resistance to the passage of a current stops the 
action. 
On page 205 he says, “A piece of muscle impacted between two 
teeth will produce considerable of a current, which is usually so an- 
noying that removal of the substance seems an immediate necessity 
to the individual.” 
Of course, when an electrician has the cause to investigate, this 
annoyance could not be produced by the simple effect of mechanical 
pressure. 
On page 208 the doctor recommends the use of tin and gold, and 
describes the method of using them : “But the better method to use 
tin and gold in the same cavity is to employ cylinders of tin only, 
and of gold only, always keeping the tin next to the walls of the 
cavity and using only gold in the centre of the plug.” I will sim- 
ply state that the interposing of tin between gold and the substance 
of the tooth as a protector of the dentine from the action of the gold 5 
(if such action existed) would not affect the polarity in the least; 
the tin would act merely as a conductor. But if I wished to form a 
little cell or electric combination in the mouth by the simple contact 
of two metals, I could hardly devise a better method, for gold being 
one of the most negative metals, a feeble action might take place 
between the two. 
Currents produced by contact alone are always extremely weak. 
A much stronger current would take place between an amalgam of 
zinc and one of silver, placed in the same position, for, although 
silver is not as negative a metal as gold, it possesses the highest 
conductive power of all metals. The tooth-substance would not be 
a factor in the case, for we all know that tooth substance is com- 
posed of salts, which always impede electric currents, the gelatine 
and water being the only material in the tooth that could act as a 
conductor. A desiccated tooth would be a complete insulator. 
Gold is not attacked by any single acid (except selenic), does not 
tarnish in dry or moist atmosphere at any temperature, and is not 
affected by sulphur, iodine or phosphorous Tin, on the contrary, 
tarnishes or oxidizes slowly in moist atmosphere. Its oxides com- 
bine with vegetable acids, and its salts in solution will attack and 
combine chemically with the substance of the teeth. Its power to 
chemically unite with tooth-substance is only equaled by mercury 
and silver. When new compounds are formed by the chemical affin- 
ity of elementary bodies, and change of molecules takes place, or 
when compounds are recompounded by the same agency, organisms 
may be destroyed or built up. In either case passive or active elec- 
tricity may be evolved. This law of chemical affinity is beautifully 
illustrated in the incubation of an egg. It is well known that the 
body of an egg contains neither phosphoric acid nor lime, but both 
these substances exist in the shell, which becomes thinner and thin- 
ner during the whole time of incubation, till the living embryon ap- 
propriates a sufficient quantity for the formation of its bones; 
part of the albumen combines with the shell for this purpose, and 
another portion forms the feathers. 
It is also remarkable that though phosphate of lime is always 
present in the urine of adults, it is not found in the urine of infants ; 
the rapid formation of bones in the first periods of life appropriates 
all of this salt. So we can rest content, if the phosphate 
of lime is present in the urine, that the supply is greater than the 
demand for it in forming tooth-substance. 
What Dr. Chase and his co-laborers wish to prove is, that gold, 
from its power to resist chemical action, is to be considered the 
worst material for filling teeth, because it is one of the most nega- 6 
tive of metals.—that is, that the dentos is dissolved and goes over 
to the negative metal ; but by his own confession his instruments do 
not indicate that dentos is a positive element in his oral battery. 
Dr. W. C. Barrett, of Buffalo, New York, in his very able review of 
the so-called ‘‘New Departure,” very successfully quotes Dr. Palmer 
against himself. In a paper read before the State Dental Society 
of New York, in 1874, Dr. Palmer says, “A porous tooth contain- 
ing an amalgam plug has in it the elements of a minute but intense 
battery capable of decomposing not only the plug but the tooth 
around it.” This early statement of Dr. Palmer’s proposes an im- 
possibility, for gold, silver, platinum and tin, fused together and 
then reduced to filings and afterwards amalgamated with 60 per 
cent, of mercury, would not and could not polarize to form an 
electric combination, much less a “battery.” The molecules of 
each separate metal would be positive and negative to each other 
in such a confusion of infinite quantities that they would neutralize 
each other’s action. I know of no means of forming an electric 
combination in the mouth except by filling a superior tooth with a 
zinc amalgam and an inferior opposite one with a silver amalgam, 
so that they would come in contact. Then I admit that a circuit 
would be formed through the moist tissues of the mouth from the 
zinc to the silver, and, in case of an acid condition of the fluids of 
the mouth, electric excitement would take place every time the two 
metals came in contact;—if the fluids were neutral, electric excite- 
ment would take place feebly. 
That electric currents should be generated in the mouth, and that 
when present they should be destructive of bony tissue, so far from 
being true from a scientific point of view, is not, I think, even 
theDretically possible, for the following reasons : 
1st. The sense of taste is an extremely delicate test of an electric 
current; signals may be tasted which even the most delicate galva- 
nometer will fail to detect. 
2d. Very strong currents of electricity have been used daily for 
months and years as a therapeutic agent in cases of paralysis, and 
it is in constant use as a stimulant to tetanize dormant muscle with- 
out being in the least destructive to bony tissue. 
It is not electricity that does the mischief; it is defective filling 
with gold and a change of molecules in other materials used for 
filling teeth, and this takes place when no current could be percept- 
ible. Diffused electricity may take place on the decomposition of 
any substance, but it must be remembered that in this instance 
electricity is the result, and not the cause, of molecular change. 
In the June (1877) number of the Missouri Dental Journal, on page 223, Dr. Chase sums up the results of his experiments and 
observations, and embodies them in the following sentences : “Gold 
is not oxidizable in the mouth, and in itself may be said to be per- 
manent, but the tooth suffers more from that fact. It is the 
tooth-substance that does not last; the metals of which plugs aie 
made last long enough. Their slow surface chemical disintegration 
is desirable in an acid condition of the mouth. A plug that will 
not do this is a greater enemy to dentos than one that will.” These 
sentences need no comment. 
In the Journal of July 15 of the same year the doctor gives 
freely the results of his experiments in dental alloys, and publishes 
three formulas. The first formula contains equal parts of gold, 
silver, and tin, amalgamated with 80 per cent, of mercury, or, if 
20 parts of tin filings are added, 60 per cent., which makes 146 2-3 
parts of tin, silver, and mercury, and 33 1-3 parts of gold. This 
amalgam, while it contains so small a proportion of gold, is far 
richer in that metal than any alloy in the market, for where platinum 
is used it only takes the place of gold or divides the honors with 
that metal. 
Now, why use gold at all ? If gold is incompatible with tooth- 
substance, so is platinum. Why use these expensive metals in such 
connection? Are there no fears that this seductive and dangerous 
gold will corrupt the virtues of the other four metals? Is it not a 
short-sighted liberality to use it in such connection when it is use- 
less ? But if it be dangerous to the integrity of tooth-substance, 
is it not culpable ? 
When Thomas Fletcher produced the platinum and gold alloy, it 
was an improvement on Dr. Townsend’s amalgam of tin and silver, 
as much so as Dr. Townsend’s amalgam was an improvement on the 
zinc and tin amalgams in use forty years ago ; and I can assure 
you it was no spasmodic fit of emotional generosity that induced 
Fletcher to add the gold and platinum to the silver and tin of 
Townsend and smelt them together, producing a more intimate con- 
nection of their particles than could have been obtained in the filings 
of the separate metals. The wide difference of expansion and con- 
traction of the several metals under thermal influence is to a trifling 
extent compensated thereby. This was his object, and this is why 
test-tubes were introduced. The elements that are constantly 
present in the body, that unite directly with silver, tin, and mercury, 
were no consideration with Thomas Fletcher, and, as far as this 
controversy has gone, I am not aware that they have been introduced 
by any one. I, therefore, with the tenderest regard for electricity, 
beg leave to present for your consideration, sulphur, iodine, and 8 
phosphorus, a trinity of elements which have a great attachment 
for silver, mercury, and tin. But more especially do I recommend 
them to the attention of the advocates of this new doctrine. 
Sulphur. 
There is no other element so widely distributed in the animal, 
vegetable, and mineral kingdoms as sulphur. Nature employs it in 
most of her operations. She presents, it under many forms among 
fossils ; charges with it the waters known as sulphurous ; mineralizes 
with it most of the metals forming iron pyrites, galena, cinnabar, 
blende, and silver glance ; causes it to pass into the vegetable and 
animal fibres, and forms an infinite number of combinations with 
the earths. Sulphur is present in horse-radish, cresses, and many 
other vegetables, and is a constituent of the volatile oils of mustard, 
garlic, and assafoetida, and of albumen and other proteids. It is 
always evolved, in combination with hydrogen,' from animal sub- 
stances during their putrefaction; and the change which silver 
undergoes when immersed in mustard or an egg shows the presence 
of sulphur, and the strong affinity it has for that metal. When 
taken into the system with food, or exhibited as a medicine, it pen- 
etrates to the extremities of the most minute vessels, and impreg- 
nates all the secretions. It shows a tendency to unite with mercury 
equally as strong as its affinity for metallic silver, for there are 
instances on record of persons having been subjected to mercurial 
medicine for a short time, and upon the outward application of sul- 
phur ointment for a few hours, the spot where the ointment was 
applied became quite black This was occasioned by the mercury 
exuding through the pores of the skin to unite with the sulphur, in 
consequence of its affinity for that substance, and a true ethiops- 
mineral was formed. A beautiful illustration of this principle is 
shown in one process of parting gold and silver: The silver being 
in excess, the two metals are melted and rolled into thin plates ; 
then a layer of sulphur and a plate are alternately disposed, where- 
upon the sulphur unites with the silver, forming a sulphuret of 
silver in the form of a black powder, which is washed out, leaving 
the gold in a spongy condition, but pure. Sulphur does not unite 
with metallic gold or platinum, but it will form an auric sulphide 
when united with the cyanide of gold. 
The constant presence of sulphur in the system, and the intense 
chemical energy of sulphur for silver and mercury, render these 
metals unfit for the purpose of saving teeth. The small amount of 
gold and platinum present in Fletcher’s or any other alloy, gives 
no protection to silver or mercury from the invasion of sulphur. 9 
Sulphuret of silver and of mercury is formed in the cavity of the 
tooth in which an amalgam filling is placed, for the reason that the 
fluids in the tooth-substance convey the sulphur to the silver. Any 
amalgam filling removed will be found to be black where it comes 
in contact with tooth-substance, I care not how the amalgam may 
have stood the test for leakage in glass tubes before using. , When 
we reflect on the complicated structure of a tooth, and consider 
the facts that a constant circulation is sustained as long as vitality 
remains, and that even in a dead tooth the same canals permit the 
fluids of the body to pass through its substance, the pleasing thought 
of a moisture-tight filling, that will not allow any moisture between 
itself and the bony walls which surround it, becomes a mere phan- 
tom. Oxygen has been accused of darkening amalgam and tin 
fillings on the outside. It does its share where the fillings are 
exposed to the atmosphere, but sulphur attacks them all over. Sul- 
phur will sever its connection with rubber after it has been vulcan- 
ized to unite with silver, if silver is placed in contact. 
Iodine. 
Iodine, next to sulphur, is one of the most widely diffused of 
elementary bodies. It vaporizes at the ordinary temperatures ; it 
is found in some minerals combined with mercury and silver; unites 
readily with the different salts, but enters into combination directly 
with metallic mercury, silver, tin, copper, and zinc, forming the 
iodides of these metals. Aside from its natural presence in the 
system, it is used largely as a therapeutic agent (stimulant, absorb- 
ent, emmenagogue, and alterative). From its known affinity for 
mercury, it is used in collutories for relieving mercurial sore mouth; 
and in cases of chronic mercurial poisoning the administration of 
iodine furnishes the most effective means of eliminating mercury 
from the system, thereby curing paralysis, neuralgia, and other 
symptoms of poisoning from this metal, for all soluble salts of mer- 
cury are poisonous. 
Phosphorus. 
This non-metallic element is widely diffused; it enters largely 
into combination with the oxide of calcium (lime) and magnesium 
in the formation of bone; and in the dentine of the human teeth 
the phosphate of lime and magnesia constitute 68 per cent., and 
in the enamel 86 per cent. Phosphorus unites readily with metallic 
salts, and unites slowly with metallic silver, mercury, tin, copper, 
and zinc, but it will not unite with metallic gold or platinum. Chloride of Sodium. 
This compound of muriatic acid and sodium, when reduced to 
dryness, forming the chloride of sodium, is found native in exten- 
sive beds, and enters largely into'all organized bodies, and is essen- 
tial to the digestion of food. A great deal has been said and 
written in regard to the combination of this salt with the mercury 
contained in an amalgam filling, forming the chloride of mercury 
(calomel), and the corrosive chloride of mercury (corrosive sub.). 
I confess that I do not see how such a compound can be produced 
in the human mouth, for the sulphate of mercury must first be 
formed with sulphuric acid, then boiled to a dry powder, the salt 
added afterwards and the two rubbed together, and then sublimed 
with a gradual heat, when the vapors of perchloride of mercury 
arising are condensed in the cool part of the apparatus, which vapors 
are the chloride of mercury. A very simple or mild chloride of mer- 
cury can be formed by rubbing metallic mercury with salt, but such a 
combination would be mechanical, and, I think, harmless. If, 
however, the sulphuret of mercury had formed around large amal- 
gam fillings, and had combined with the salt in the system, or with 
that taken into the mouth, there would certainly be produced a 
chloride of mercury of a very mild character; as all soluble salts 
of mercury are poisonous, and it being a well-established fact that 
some persons are more susceptible to the influence of mercury than 
others, if there were no other reasons for discarding the use of 
this metal in the mouth, then the fear of this combination alone 
should be sufficient to throw it out from the list of filling materials. 
In the selection of filling materials, to secure a good result it is 
indispensable that the filling should fit the walls of the cavity per- 
fectly, and that it should exclude completely all those external 
agencies which induce decay ; that it should be solid and undivided 
in all its parts, fitting it to resist all pressure likely to be brought 
to bear against it; and, finally, that it should resist to the fullest 
extent chemical action, thermal influence and attrition. 
So long as we are confined to the use of metals for filling 
material, there is no metal or combination of metals or substances 
that has yet been found that can take the place of gold for that 
purpose. It possesses more of the valuable properties of the force 
of cohesion (hardness, elasticity, malleability, ductility, etc.) than 
any other metal; it is capable of receiving and retaining additional 
powers of cohesion by the application of coercive force ; and when 
combined with small quantities of its sister-metal, platinum, its 
hardness and elasticity are greatly enhanced by the joint action of adhesion and cohesion ; in fact, the force of cohesion in gold is so 
powerful, that at ordinary temperatures it will unite under coercive 
force almost equally as "well as iron or platinum under the influence 
of heat. Like platinum, it is not influenced by any single acid or 
alkali; it does not tarnish in moist or dry atmosphere at any tem- 
perature, and it is not affected by sulphur, iodine, or phosphorus. 
All metals lose their natural coherence when alloyed, and when 
amalgamated with mercury the standard of cohesion is further 
reduced. Silver and mercury do not oxidize in the atmosphere at 
ordinary temperatures, but when the silver is amalgamated with 
mercury the silver oxidizes, owing to its having lost much of its 
cohesive force. Platinum and mercury do not unite,—the hardest 
metal to fuse and the metal which is in a fused state at ordinary 
temperature have no sympathy for each other. Copper will not 
unite with mercury, but will unite with the nitrate of mercury, and 
the combination will then receive additional quantities of the metal 
mercury. 
On contact, gold and tin, either separately or combined, unite 
with mercury perfectly, and give up their cohesive properties in 
their combination with the mercury ; for this reason the amalgam 
does not harden, and the gold and tin lose all their individuality in 
the combination. 
Silver and zinc, either separately or combined, unite readily with 
mercury; they lose much of their cohesive force, expand in harden- 
ing, destroying the fluidity of the mercury, and losing all their 
own peculiar properties. 
Cohesion of Amalgams. 
The superficial expansion of a metal is equal to twice its linear 
expansion, and the cubical expansion to three times the linear. 
The metals used by the dental profession are the following, the 
most expansible standing first in order: mercury, zinc, tin, silver, 
copper, gold, platinum. 
Mercury is so expansible that it is classed among the liquids, and 
vapor arises from it even at the freezing-point of water in sufficient 
quantitity to whiten gold-leaf; the temperature of the human body 
(98 ° F.) is sufficient to overcome the whole of its cohesive force. 
Thus mercury, tin, and silver, forming nearly the whole body of 
amalgam fillings, must be measured by their cubical expansion 
under the influence of heat, and a corresponding contraction under 
the influence of cold. 
Expansion and Contraction of Metals. Conduction. 
The thermal conductivity of some of the metals in use by the den- 
tist stands in the following order : silver, copper, gold, tin, platinum 
and bismuth. The resistance offered by mercury to the conduction 
of heat is far less than that of water, it, however, offers more 
resistance to the conduction of heat than bismuth, which stands the 
lowest in point of conduction in the table of the conductivity of 
metals. Mercury is therefore an intermediate body, occupying a 
position between liquids and solids in its power of conduction, as 
well as in its power of coherence. 
New and original research requires a singular independence of 
mind, and, unfortunately for the cause of progress, such minds are 
at all times rare. The electro-chemical theory for the destruction 
of tooth-substance in contact with gold only lacks the facts to sus- 
tain it, but when men need facts to sustain a favorite or plausible 
theory, they are not long in seeing the facts required; everything 
becomes clear in the uncertainty; a little experiment, a little 
straining of the eyes, and all is seen that they believe they ought 
to see. And thus they sail on an unknown ocean, trusting to hypo- 
thetical charts, to compasses of their own invention, in which the 
essential feature is the omission of that magnet which can alone 
give security. 
Yet for ages this has been the only seamanship deemed necessary 
or practical in the history of medicine and its many specialties. 
And how many still trust to it implicitly ! Thanks to the inroads 
that physical science has made on our domain, the dawn of a better 
day is fast approaching, and the next generation must witness dis- 
closures not less startling than those which have electrified the 
present day. In the meantime what we want is a careful classifi- 
cation of existing facts (physics, not metaphysics), their exact rela- 
tion to each other, the great aim being to discover a genuine 
sequence of phenomena traced link by link to a definite cause. 
The opinions advanced by Professors Flagg and Chase, and Dr. 
Palmer, are acquiesced in, either actively or passively, by many of 
those with whom they are working, as well as by others wTho are 
but slightly acquainted with the subject themselves, but who very 
naturally look up to the professors in their scientific character as 
authorities in all such matters. Were these simply theoretic opin- 
ions, they might very safely be left to the ordinary action of that 
silent criticism which quietly hands over to oblivion so many errors. 
But when we find them taken up by active, energetic men, and used 
as an important portion of their working machinery to increase the 
sale of mercurial compounds for filling material, they must be met in a formal and emphatic manner; and this becomes all the more 
necessary when we find them countenanced by writers in the same 
profession who have little, if any, monetary feeling in the matter, 
but who have simply been misled by superficial considerations. 
In recapitulating some of the observations recorded in this essay, 
I desire to call attention to the following propositions: A voltaic 
battery cannot exist except in the manner directed by Professor 
Volta, the inventor or discoverer. It consists of an equal number 
of pieces of zinc, silver, and pasteboard ; the pasteboard pieces are 
soaked in a solution of chloride of sodium, and then are piled with 
the metals in the following manner: zinc, silver, pasteboard, and so 
on, in the same order, the uppermost plate being of silver, and the 
undermost plate of zinc. These exterior plates, to each of which 
a wire is attached, form the terminals or poles of the pile. This 
was the first form of those instruments now so well known by the 
general name, “galvanic battery.” The word battery is not appli- 
cable to any arrangement of elements present in the mouth. An 
electric battery is a collection of distinct cells, each cell so arranged 
in its elements as to secure an electric current and each cell so joined 
to the others as to secure an unity of action in the whole, thus 
forming a battery. 
The methods of construction of batteries for the generation of 
electricity are various and peculiar, both in regard to the material 
used and the arrangement. Thus we have a Smee’s, a Grove’s, and 
a Daniell’s battery, each bearing the name of its inventor; and 
when “Dentos and Gold” shall be proved to form an electrical com- 
bination, and be proved to be a battery, it may also bear the name 
or names of the inventors. 
Resume. 
If vapor rises from mercury at the freezing point of water in 
sufficient quantity to whiten gold-leaf, an amalgam filling subjected 
to the heat of the human body (98 ° F.) must gradually part with 
its mercury by vaporization. This can be demonstrated by select- 
ing a few old amalgam fillings, and, after accurately weighing 
them, submitting them to a heat sufficient to evaporate mercury. 
This being done, let the mass cool and again weigh, when it will 
be found to weigh as much as it did before heating. As a further 
test of the divisibility of mercury under the influence of heat, take 
one hundred parts of Fletcher’s alloy, add sixty parts by weight of 
mercury, and allow it to harden; then submit it to a sufficient heat 
to vaporize the mercury, and weigh the residue, and there will be 
found one hundred parts,—the mercury having disappeared. Therefore, when an individual, either by bad counsel or a false 
economy, has been subjected to mercurial or amalgam treatment for 
diseased teeth, we find that fifty parts of the mercury out of the 
sixty used in forming the amalgam are vaporized by the heat of the 
body in a few years, and taken into the system in small but regular 
quantities,—the most potent manner of administering mercury for 
a constitutional effect. Should not this be sufficient to induce every 
conscientious practitioneer to discard all amalgams from the list of 
filling materials, and be the means of inducing others to be less 
presumptuous in their speculations, and more honorable and reso- 
lute in their practice. APPENDIX. 
Read before the St. Louis Dental Society, February 15th, 1881. 
Gentlemen:—At the twentieth annual session of the American 
Dental Association, I caused to be presented a short paper on 
“Oral Electricity and the New Departure,” and, although not a 
member of the association, the censors did me the honor of decid- 
ing that it should be read before that body. The paper was accord- 
ingly read by the secretary and elicited some discussion, and, I re- 
gret to say, excited a spirit of coarse arrogance in one of the mem- 
bers, sadly out of -place in a deliberative body of scientific 
gentlemen. 
On this occasion I purpose to continue the subject by reviewing 
my reviewers. I find in the January number of the Dental Adver- 
tiser (a journal devoted principally to the interests of Mr. Thomas 
Fletcher) a criticism by Thomas Fletcher, F. C. S., on a paragraph 
in my paper read in Boston. It is as follows : 
“Dr. J. R. Patrick, of Belleville, 111., forwarded a paper to the 
above meeting, which was read by the secretary, and amongst other 
matters, contained the following : 
‘When an individual, either by bad counsel or a false economy, 
has been subjected to mercurial or amalgam treatment for diseased 
teeth, we find that fifty parts of the mercury, out of the sixty 
used in forming the amalgam, is vaporized by the heat of the body 
in a few years and taken into the system in small but regular quan- 
tities—the most potent manner of administering mercury for con- 
stitutional effect. Should not this be sufficient to induce every 
conscientious practitioner to discard all amalgams from the list of 
filling material, and be the means of inducing others to be less pre- 
sumptuous in their speculations, and more honorable and resolute 
jn their practice V 
“Save us from our friends ! If Dr. Patrick knew anything 
about this subject, he would know that there is not and never was, 
except in the imagination of the ignorant, the smallest atom of 
truth in his statement. Such champions for gold plugs simply 
bring ridicule on their own cause, and Dr. Patrick cannot bring the 
smallest proof to back his statements. 
“To test the question of evaporation of mercury from plugs, I 
made twelve, each of 200 grains weight, of different alloys, varying in proportions from 10 per cent, to 80 per cent, of mercury. These 
plugs I placed in the main steam pipe leading from the boiler to 
our steam engine, which was running on an average 14 hours daily 
—the whole of the steam used passing over the plugs. At the end 
of one month four of the plugs were removed. One was partially 
fused and the weights were respectively, 200.00, 20‘0.05, 200.10 and 
200.40 grains. There was no loss, but an increase in weight 
from surface oxydation. At the end of three months the remain- 
der of the plugs were removed and all showed a trace of increase in 
weight from the same cause. 
“I pray Dr. Patrick to digest the above, and in future to make 
statements which he is in a position to prove, if he wishes his state- 
ments to have any value. 
“Thos. Fletcher, F. C. S. 
“Warrington, England.” 
In regard to the paragraph that Mr. Fletcher criticises, I will 
simply state that it contains the least amount of objections to the 
use of amalgam fillings contained in the whole paper; and the 
objection contained in the paragraph criticised by Mr. Fletcher is 
based on the following facts : 
1st. After cleansing some old amalgam fillings, I submitted 
them to a fusible heat for a sufficient length of time to evaporate 
any mercury that they might contain, at the same time causing a 
current of air to pass over the melted mass, in order to drive off any 
mercurial vapor that might arise, when, upon cooling, I found the 
fillings had lost less than ten per cent, of the quantity of mercury 
usually employed in the formation of amalgam plugs. That it was 
mercury which was lost I knew by the vapor that had condensed on 
the gold leaf which I held over the melted amalgam. One mass of 
amalgam fillings sustained no loss when fused, and did not whiten 
gold leaf. The precaution in using gold leaf upon which to con- 
dense and retain the vapor of mercury, and the current of air to 
drive it off when it arises is to prevent the mercury Jrom return- 
ing to the mass upon cooling, which it is as sure to do (if this precau- 
tion is not taken) as the column of mercury in a thermometer upon 
cooling will return to the bulb from whence it arose. The column 
of mercury confined in the capillary tube of a thermometer rises in 
a metallic state only because it is in a vacuum, but the same metal 
unconfined would rise in the form of vapor ; and while this is true 
of all bodies under the influence of heat, it must ever be remem- 
bered, in the discussion of this question, that mercury is the one 
most susceptible to this influence. 2d. The many cases reported 
to me by reliable and competent dentists, independent of the few cases in my own practice, where many large amalgam fillings had 
been employed to arrest decay, in which the mucous membrane, and 
particularly the edges of the gums presented an appearance approx- 
imating to ptyalism, keeping the gums in a chronic state of irritation; 
and this too when a reasonable amount of cleanliness had been 
exercised. Upon removing the amalgam fillings and substituting 
gold, the mouth and gums assumed a healthy condition, and all that 
fetor peculiar to ptyalism entirely disappeared. 
Certainly, this is good presumptive evidence that the amalgam 
fillings were the cause of the unhealthy condition of the mouth, and 
gave me full warrant to use the language in the paragraph quoted 
by Mr. Fletcher. I am very well aware of the inertness of mer- 
cury in its uncombined state, but when exhibited in minute mechan- 
ical division, as in the ointments and liniments, or in a state of 
vapor, it produces all the effects on the system peculiar to the metal 
when chemically prepared. Either of these mechanical preparations 
of mercury, if rubbed on the surface of the body or taken into the 
stomach, produces, in consequence of its absorption, the general 
effects of mercury upon the system ; all that is necessary is minute 
division, either by trituration or by vaporization, and the quantity 
of mercury used, either by rubbing or by fumigation, is not so 
important as the amount that is absorbed, for in the law govern- 
ing therapeutics, as in physiological law, it is not the amount one 
eats that nourishes, but the amount that is digested. Persons 
who work with mercury, either in the mines where it is found, or in 
the shops where it is used in manufacture, suffer from ptyalism. It 
is, therefore, not necessary that mercury should enter into chemical 
combination with other elements before it is administered, in order 
for it to produce its peculiar effects. All that is necessary is mi- 
nute division, that it may be readily absorbed. The body contains 
all the elements necessary for chemical combination after the absorp- 
tion has taken place.* 
♦In the discussion which followed the reading of the former paper, Dr. 
W H. Atkinson, of New York, denied the possibility of mercury being 
absorbed into the system without first being combiued with some other 
agent, and cited the case of the workingmen engaged in the manufacture of 
looking-glasses, and ignored thefact that the men so engaged suffered from 
the influence of the absorption of mercury. In reply to this assertion of 
Dr. Atkinson, I will simply refer the reader to the following works : 
National Dispensatory, United States Dispensatory, 13th edition ; A Treat- 
ise on Therapeutics, by A. Trosseau ; and H. Pidoux, revised and enlarged 
by Constantine Paul. As these works are received with some favor by 
men of science, and are deemed reliable upon the subjects of which they 
treat, I hope I will incur no ill-will if I give them the preference, as author- 
ity, to the dicta of Dr. Atkinson. Now, I claim that in the living subject, the human mouth, with 
its teeth well packed with mercurial compounds, furnishes all the 
apparatus necessary for trituration, and the membranes of the mouth 
a sensitive and ready means of absorption, without the assistance 
of the temperature of the body to vaporize the mercury contained in 
the amalgam. 
It may be some consolation to Mr. Fletcher and to all manufac 
turers, dealers and manipulators of amalgam compounds that it is 
no„t the use of these amalgam compounds that I am combating, but 
the abuse ; and the advocacy of the exclusive use of these com- 
pounds by their manufacturers and defenders (which are almost syn- 
onymous terms), and the dogmas which they have promulgated. 
Now I desire Thomas Fletcher, F. 0. S. and all other manufactur- 
ers of alloys to remember that I am not a manufacturer of any form 
of gold, nor am I interested in any way in the sale of any article 
used by the dental profession. I therefore feel that in the discus- 
sion of this question I approached it with clean hands, and with a 
mind ungoverned by the influences of pecuniary benefit, even if I 
have not been able to convince some persons of the truths contained 
in the paper. On the other hand I do know that they who have 
written the most against the use of gold as a filling material for 
teeth are either interested in the manufacture of compounds for the 
formation of amalgams, or have compounds of their own upon the 
marker, * which recalls to my mind those immortal lines of the poet 
Burns. 
But Och ! mankind are unco weak, 
And little to be trusted : 
If self the wavering balance shake, 
It’s seldom right adjusted. 
Mr. Fletcher requests me to digest his experiment for the evapor- 
ation of mercury from plugs. I have done so, and were it not that 
*The Standard alloy is manufactured by Eckfelt, Dubois & Co., near Nor- 
ristown, Pa., office No. 106 Eleventh street, Philadelphia. Eckfelt and 
Dubois are the metallurgists and assayers of the Philadelphia mint, referred 
to by J. Foster Flagg, in his paper on the “Basal Principles of the New 
Departure,” and the Co , I presume, is Dr. Flagg, whose office I am informed 
is No. 106 Eleventh street, Philadelphia.” In the July number of the Mis- 
souri Dental Journal of 1877, I find a short article written by the editor, 
Dr. Chase, on “Dental Alloy.” After enumerating the many different alloys 
then upon the market, with their prices per ounce, the article concludes 
with the following remarkable sentence: “What is further needed is about 
three alloys, of gold, silver and tin, containing from 20 to 33 per cent, of 
gold, put upon the market by a party who can command the confidence of 
the entire profession.” Whether that party so earnestly desired was ever 
found I cannot say ; but Dr. Chase aid put a compound upon the market 
soon afterwards. I find F. C. S. following his name, I never should have suspected 
that the description of his experiment had been written by a Fellow 
of a'scientific society. Compare the very rough chemical manipu- 
lation of placing twelve amalgam plugs in a main steam pipe for 
one month, at an average of fourteen hours daily, the heat, or the 
pressure of steam not given, cooling off alternately, ten hours in the 
twenty-four; at the end of that time four taken out. one partially 
fused. Query? Which one? The one with 10 per cent., 60 per 
cent, or 80 per cent, of mercury ? He does not say. Mr Fletcher 
will find, if he reconsiders his experiment, that a plug made with 60 
per cent, or 80 per cent, of mercury, could not well be considered a 
solid, in or out of a steam pipe; for from 20 per cent, to 40 per 
cent, of alloy is hardly sufficient to deprive mercury of its fluidity. 
But the increase by oxidation is the most remarkable feature of this 
experiment, which Mr. Fletcher determines by delicately weighing 
to the fraction of 5-100 or 1-20 of a grain! Now the fractional 
accuracy of Mr. Fletcher in the pursuit of oxygen, challenges my 
admiration ; and it is to be regretted that he did not devote some 
of that accuracy in the pursuit of mercury. For this delicate 
weighing of the plugs after steaming, would not even give the 
amount of oxygen, without each element in the rest of the mass 
upon which the oxidation had taken place was known with equal ex- 
actness ; for mercury (being very mercurial) might have left, and 
oxygen might have taken its place ; what, then, would become of 
the 1-20 of a grain of oxygen? Again, what metallic oxide formed 
on these plugs of Mr. Fletcher’s ? Was it oxide of tin, silver or mer- 
cury ? or was it an oxide of the metal of the steam pipe? Until 
these questions are properly answered, a common pair of steelyards 
would have answered all the demands of exactness for such a steam- 
pipe analysis, and until Mr. Fletcher can present a better analysis 
of the question at issue, he will do well not to presume too much 
on the “ignorance” of the average American dentist. 
As Mr. Fletcher does not give the steam pressure, or the heat the 
amalgam plugs were subjected to, I will take a medium pressure of 
steam, or its temperature, as the maximum heat, say 70 pounds 
pressure or 806.40 F., for my experiment, and I will make five plugs 
of Mr. Fletcher’s gold and platinum alloy with 10, 30, 50, 60 and 
80 per cent, of mercury. I will now place these amalgam plugs in 
one-inch test-tubes, and then introduce a cork into each tube, first 
attaching a small piece of gold foil to each cork, pressing the corks 
with the foil down to within the eighth of an inch of the amalgam. 
I will now place these five test tubes and contents in the sand bath 
surrounding the bulb of a thermometer, and subject them to a heat less than 306.40 F., when at the expiration of one half hour the 
gold leaf will be found whitened by the vapor of mercury * 
I am very well aware that the volatility of mercury is somewhat 
retarded by the admixture of other metals, but this admixture does 
not reduce the mercury to a solid ; and it is only a question of time 
as to the liberation of this volatile metal from the compound with 
which it forms an amalgam. The dissimilar atoms of the com- 
pound unite by adhesion with the mercury with more or less force, 
according to the definite proportions of the elements forming t!:e 
compound ; and their affinity for the mercury, will determine the 
time of its retention. Thus in the distillation of mercury, if pushed 
too far, tin and lead will be carried over with the vapor of mercury, 
whereas, gold and silver under the same conditions would remain in 
in the retort, while the mercury would be carried over to the re- 
ceiver in a free state. 
If what I have written on this subject has contributed in the 
least to extend the knowledge of the nature of materials employed 
in the preservation of the teeth, or if I have presented any new views 
to the profession that may lead to the solution of problems—or have 
shown that agents ever present in the body do act on the baser met- 
als used in filling teeth, forming salts in a manner never before sus- 
pected ; and if by denouncing the pernicious practice of promulgat- 
ing theories and advocating the use of material suited to the 
capacity and ability of individuals, will in any manner assist in 
removing the stumbling blocks that stand in the way of sober deduc- 
tion and progress, I shall feel that I have done something towards 
paying a debt to my profession that may lead to the promotion of 
human comfort. 
*At the expiration of the time the thermometer indicating 220° F., the 
tubes were taken from the bath, the corks removed and the foil examined, 
and all were found to be more or less whitened —Recording Secretary.