4»V
A-
<^ C1"
?S*   e



<*c
« H**r 
■—> ■■ ' ", '■'■■■;■ -
|      Surgeon General's Office
s
INNB7

 
 
 
                     A N
    INAUGURAL  DISSERTATION
                  ON THE
PRINCIPLE OF  ANIMATION:
            SUBMITTED TO THE
          EXAMINATION
                  OF THE
   REV. JOHN EWING, S. T. P. PROVOSTs
                     THE
     TRUSTEES & MEDICAL FACULTT,
                    OF  THE
         UNIVERSITY OF PENNSYLVANIA,
          On the twenty-feventh of May, 1802,
             FOR THE DEGREE OF
   DOCTOR OF  MEDICINE:

         By JOSEPH MACRERY,\
               OF DELAWARE.
Principio caelum, ac tersas, camposque liquentes,
Luccntemquc glojmfi* lunae, titiniaque astra,
Spiritus intubate, totatnque infusa per artus
Men* agitat molem, et magno se corpore miscct.
           //f%VS~        V«G. JEjf. Yl.
^<>.;:-.'<><>t><^<.>e:>.i>c><>c><>«><><><><><>iS><><>C><><>o<>OM!><>!;><

            WILMINGTON:
          PRINTED  BY BONSAL AND NILS!.
1802. 
 
              T O




     JAMES TILTON, M. D.




          PRESIDENT OF THE




MEDICAL SOCIETT OF DELAWARE,




           THIS ESSAY IS




        DEDICATED,




          AS A MARK OF




   RESPECT AND GRATITUDE,




      FOR THE MANY FAVOURS




          CONFERRED ON HIS



  SINCERE FRIEND AND AFFECTIONATE PUPIL,




                 JOSEPH MACRERY. 
 
            ON THE

PRINCIPLE OF ANIMATION.
   ± HE  principle of  animation  has  been
known by a great variety of names.   We have
the           of Hippocrates ; the
of the Platonists and Stoics;  the anima  vegi-
tans of the writers of the middle age ; the
archeus of Van Helmont and Stahl; the aether
of Newton ; " the Form," of Harris ;  the vis
vitas of Haller;  the  materia vitae diffusa of
Hunter ; the nisus formativus of Bluminback ;
and the fire or electricity  of  Hutchinson and
Valli.

   There appears to be two principles during
life, which are continually opposed to each
other.  First the principle of animation, which
by the energy of its unifying  power, is conti-
nually separating common matter from its ele-
mentary state, harmonizing it with itself, and
organizing it into systems : and another prin-
ciple which we call nature, which through the
medium of the chemical, or different affinities,
of different modifications of matter, is perpetu- 
                  (   *  )
ally tending to reduce them to a common (rate.
The usual  process for this end, is fermenta-
tion, putrefaction and gravitation ;  which pro-
cess begins in organized systems,  as soon as
life ends.  Nature is the efficient cause, by the
energy of which the symmetry of the material
world is preserved—is the bond of union be-
tween  the  different parts  of common, as  the
principle of  animation is between different
parts of living matter.  As soon then as  the
matter of living systems looses this participa-
tion of life, it becomes amenable to the  gene-
ral law of physics, and the system is resolved
into its constituent parts.

   In considering the principle of animation, I
shall not only view it as it exists in man,  but
as it exists throughout the whole of the animal
and vegetable kingdom.  Simple life appears
in its most perfect state, in those animated or-
ganized systems, which possess the preserva-
tive, assimitative, reproductive  and procrea-
tive powers, in the highest degree.  From the
earliest ages, life has  been  supposed  by all
men, to depend on a certain vivifying princi-
ple, by the energy, of which, matter is depriv-
ed of its sensible qualities ; is reduced from a
heterogeneous to a homogeneous state, and is
converted  into ,organized animated systems. 
                  (   1  )
These systems,  while they retain the princi-
ple of animation, possess the power of acting
on matter,  and preserve themselves by resist-
ing its different affinities ;  but as soon as this
vivifying principle departs, death takes place;
then matter instead of being acted on by the
system, acts on the system,  and by means of
the different affinities, fermentation and disso-
lution follow.

  Before we enter into the  consideration of
what this vivifying principle is, it will be ne-
cessary in the first place,  to take some notice
of an hypothesis that has lately been promul-
gated, which proclaims  life to  be a forced
state ; an effect  merely of causes which are
dead !—for if this be true, a vivifying principle
is out of the question, and  our  labor  is at
an end.

  Doctor Brown, an eccentric  genius of the
last century,  was  the author of  this hypo-
thesis.  He asserts  that the action of stimuli
on  the excitability  of the  system produces
excitement, which is life.   Excitability he de-
fines to be a something residing in the nervous,
and muscular fibres, which has  the  capacity
to be acted on by stimuli ; but he is unable
to determine whether it is a  quality or a sub- 
                  (  8   )
stance ; and  further maintains, that a certain
determinate portion is allotted to every living
system.  If this were really the case, mankind
would pass on from their birth, to their death,
in a continued course of wakefulness. In order*
to get clear of this, and other facts, that militate
against the above hypothesis, he  asserts that
there is a continual production, exhaustion
and accumulation of this principle during life.
Thus he is forced to contradict himself in the
most fundamental axioms of  riis  theory.*—
Stimuli he defines  to  be  certain  substances
that have the  power of acting on the principle of
excitability, which, he says, is not life, for "life
is the sole effect of stimuli ?"—-From a view
then  of  this doctrine  it would appear, that
the excitability decreases in proportion to the
increase of excitement, and vice versa.   Of
course, in infancy and  youth,  where there is
much excitement there should be little excita-
bility ;  and in  old age, when there  is but little
excitement,  there would be a total  accumula-
tion Of excitability. If this were the real state
of things, instead of having " a continual ten-
dency to death,"  we would have a  continual
tendency to life ;  from the increase of excita*
bility in the ratio with the decrease of excite-
ment, and life might be perpetuated ad  infini-
tum  by  the  proper  application of stimuli. 
                  (   ».)
Thus we would be forced to live instead of be
ing " forced to die."  Brown's notion of vital
action must have been strangely confused. In
the first place, he  defines excitability to be  a
capacity in the organized system, to produce
motion, or excitement  on the application of
stimuli.  This is life.  We have many familiar
examples of this mode of action. A steel spring
has the capacity to be acted on, to produce
motion;  a stone has the capacity  to be acted
on ; a top has the capacity to be acted on ; all
move when the stimulus is applied, but no life
is produced.  Capacity  implies  passiveness,
and is therefore much  more applicable to dead,
or common, than to  living  matter.  Yet it is
obvious, that he grounded his system on the
action he  saw common matter display.   The
animated, organized system, retains its vitality,
not by its capacity to be acted on, by stimuli,
but by their capacity to be acted on, by its vital
assimilative powers.  As soon as death takes
place,  this order is inverted, the  system then
posesses  the capacity to  be  acted on by  air,
heat, and the other stimuli; the product is not
life; but putreiaction, fermentation and the re-
solution  of the  system into  its   constituent
parts.   Indeed,  Dr. Brown  appears  to have
begun where  he  should have  ended.   He
                    B 
                ■(  10  )
makes life the effect of the action of matter on
inanimate organized systems ;  when it is well
known, that the action of matter on such sys-
tems, invariably  produces  disorganization,
and decomposition. Instead of making action
the effect of life, he makes life the effect of acti-
on ; "for in action (excitement)," says he " the
true cause of life consists, the effect of the ex-
citing powers  acting  on  the  excitability."
Life therefore does not consist in the excitabi-
lity alone, or in the exciting power alone, but
in both together.  Further, he and his follow-
ers  assert action  to be  the sine  qua non of
life.  But life may, and does exist,  without ac-
tion ; as in  asphixia, and in hybernating ani-
mals.  The seta  equina, wheel polypus,  and
many others may be dried in the sun for years ;
or baked  in an  oven, till they are like dried
gluten,  without hurting  their vital principle ;
and may be revived at any length of time, by
moistening them with water. The seeds of ma-
ny vegetables, retain their vital power for cen-
turies. Action is an effect of organization ; but
organization is an effect of the principle of life ;
organization therefore is  the final,  and not the
efficient cause of life.

  The Dr.  maintains, that the whole pheno-
mena of  life, depend on the operation  of sti- 
                  (   11  )
muli—on a  certain arrangement of  matter,
constituting the principle of excitability : but
he never  enquired how this  arrangement was
formed,  and by what power it was produced.
He must have supposed that bodies are formed
in a manner  somewhat similiar to the  chrys-
talization of  salts ;  and then life created by
the action of matter on organized systems,
which were before inanimate.  This is indeed,
a  " forced state," as he calls it. Organization
is generally  supposed to be  an effect of life.
But here we  see life an effect of organization,
and posterior to it; or in other words,  the ef-
fect preceding the cause.  This  doctrine fa-
vours not a little of Atheism ; as it proclaims
the creation, and existence of an effect without
a cause ; for if life is neither in the excitability,
nor in the stimuli,  but is produced by their
action on each  other, it should be a tertium
quid, or neutral compound.  But that liie is
any thing like  a  compound of these agents,
none  of his supporters will pretend to assert.

   Philosophers and  physiologists have gene-
rally agreed in placing the vital principle in the
brain and nerves,* constituting the principle of
sensibility; or  in  the  muscles, forming the
principle  of  irritability.  If we  take but a
slight view of the vital principle, as it is found 
                 (  12  )
through the whole of animated existence,  we
will find at once,  that irritability must be the
principle of animation ; for a great part of the
animal, and the whole  of the vegetable king-
dom,  have neither brain nor nerves ;  yet they
have all irritability, although not all muscular
fibre,  for   irritability  may,   and  does  exist
without it.  Even in  man,  and some of the
higher  orders of animals,  where these two
principles are very intimately interwoven, they
may,  and do exist independently of each other
for some  length  of time; as in foetus' born
alive without heads ; and when, what is com-
monly called death has taken place, the sensi-
bility has merely left the body, the vital or irri-
table principle still exists.   In this  state the
lymphatics continue to absorb.  A muscle cut
from  the body, trembles and palpitates.   The
heart contracts for some length of time after it
is separated from the system, and the intest-
ines, when torn from the body, and placed on a
table, continue to roll and move on each other,
until  they become stiff and cold.  It  is owing
to the remains of  life in the  muscles, that the
body maintains whatever situation it is placed
in at  death, until the organization fails,  and
decomposition begins to take place.  This de-
composition occurs sooner or later, in propor- 
                 (  13   )
tion as the irritable or vital principle has been
expended before death.  In some cases it be-
gins immediately.  Oxen  over-driven before
they are slaughtered, and the bodies of per-
sons killed by electricity or poison, soon be-
come putrid.  This vital  principle exists in
some affections of the body, independent of the
sentient, even while what is called life conti-
nues  ; as in palsy.  It survives its separation
from  the brain, as in frogs and turtles, which
live weeks and months without their  heads;
and even its connection  with the rest of the
system, as in animals that continue to live after
being cut into a number of pieces, as in polipi
and sea anemones.  Those functions called
vital, as the circulation by which the system
lives, depend entirely on the irritable principle,
and continue  an unwearied course  of action
through life.  Whereas a state of rest is indis-
pensibly necessary, to those which depend on
the nerves and volition.   The mind and nerv-
ous system, so far from being necessary to
simple and perfect  animal life, appear to be a
real burden, and enemy to it; simple animal
life subsists much better  without them : for
whenever volition interferes,  it deranges the
animal functions,  and tends to destroy the pre-
servative prin ciple.  This appears to  be the
reason, why the vital functions are removed as 
                  (   1*  )
far as  possible beyond the reach of volition ;
but still this principle has such power in man,
as frequently to destroy life, and always has the
effect to weaken it.  So that we  generally find
the living powers  to be in the inverse ratio of
the intellectual, which are often strongest in the
most rickety, decrepid and deformed systems.
Newton, Pope, and many other celebrated ge-
nius', might be adduced in proof of this asser-
tion.   Indeed,  no  kind of exercise  appears to
wear out the vital  powers sooner than that of
the mental faculties.   The organs of the vital
functions have  such a small portion of nerves
distributed to them, that  their very existence
was  for a long time denied.  These nerves ap-
pear to serve merely as a connecting  medium
with the system; for the vital functions of the
organs which they supply, are carried on best
when the will is quiescent.   After sensibility
has become extinct, and  what  is  commonly
called  death has taken place,  as after suffoca-
tion, by operating on this vital irritable prin-
ciple, we can restore the circulation, reanimate
the  nervous system,  and  recover that  life
which  seemed entirely to have left  the  body.
This, with many other facts, proves the irrita-
ble principle to be the prime mover and source
of life.  The heart when it appears as a punc-
tum saliens in the  midst of the gelatinous em-. 
                 (  15  )
brio, acts wholly by the energy of this princi-
ple, for at this time there is no appearanee of
either brain or nerves.  The source then of all
the actions  of life  is irritability ;  its diminu-
tion debility ; its absence death.   We will,
next in order, consider what this principle is,
and what it depends on.  Some have asserted
that it  depends on the brain and nerves :  but I
hope we have already shown, that sensibility,
and not irritability depends  on the  nerves.
A later, and very generally received opinion is,
that oxygene is the principle of irritability.

   The necessity of oxygene in  respiration,
has been explained by Godwin,  and several
others.   But Dr. Girtanner  is  the first who
openly maintained  oxygene to be irritability,
the proximate cause of life !  As the Dr. is the
founder of  this hypothesis, and may be  con-
sidered its principal supporter, I will just state
a few  of his leading principles, as nearly in his
own words, and in as concise a manner as pos-
sible.

   Axiom 1st.  " The irritability of organized
bodies is always in a direct ratio of the  quan-
tity of oxygene they contain,"

   This  is by no means true, even in man, for 
                 (  i«   )
we find that the system is more highly irrita-
ble in the foetal state, and shortly after, than at
any other period of our existence ;  the blood
of the foetus is of a darker colour than that of
the adult, this is easily  accounted for, when
we consider that it receives its oxygene sole-
ly from the mother, by means of a tedious cir-
culation, through the medium of the placenta,
where the blood, as is evident from the black
colour of the placenta,  has  already became
venous.   Even for some time after birth,  al-
though the system  is  highly  irritable,   the
blood is but  partially oxygenated ; owing to
its imperfect transmission through the lungs.
The foramer ovale sometimes continues open
for a year, or more, without  any apparent
inconvenience.   And with  respect  to  the
greater part of the animal, and the whole of
the vegetable kingdom,  oxygene  so far from
being the  principle of irritability, or life, is
thrown out from their whole  surface as noxi-
ous  and dead; at the  same time  that they
thrive, and grow in proportion to  the quan-
tity of azotic, and carbonic acid gas, in which
they are inveloped.

  Axiom 2d.  " Every  thing that increases
the quantity of oxygene in organized bodies,
increases at the same time their irritability." 
                  (   17  )
   To illustrate and substantiate this position,
 he adduces the phenomena attending on the ac-
 tion of the mercurial salts, and oxydes upon
 animals, the symptoms of which are the same
 as in  the scurvy;  which he asserts is a di-
 sease of super-oxygenation.  But all thephe-.
 nomena of scurvy, as well as its cure, prove it
 to be a disease of de-oxygenation.   And oxy-
 gene  when accumulated  in organized inani-
 mate systems, instead of rendering them irrita-
 ble produces fermentation and decomposition.

   His theory of vital action is as follows.—
 "All substances which come in. contact, with
 the living  fibre, may be comprehended under
 three  classes."

   1st. " Substances which have the same affi-
 nity to  oxygene with the irritable fibre, are
 inert:"

  2d. " Substances which ha^e a less affinity
to oxygene than the fibre has, surcharge  it
with oxygene, and produce the  state of accu-
mulation :  these may be  called negative sti-
muli."

  3d.  " Substances which have a greater affini-
                     C 
                 (  IB   )
ty to oxygene than the fibre has, deprive it of
oxygene,  and produce the state of exhaustion :
these may be called positive stimuli."  Ac-
cording  to axiom 2d, 'then, negative stimuli
Oxygenate the  fibre-,  and destroy life by not
supporting action.  I would ask, do cold and
hunger,  which are negative stimuli (for they
operate in the way all other negative stimuli
are supposed to do, by not supporting action)
Oxyginate the fibre ?  And is it likely, that the
salts, and calces of metals, as red precipitate,
corrosive sublimate, lunar caustic, and  white
arsenic, which he supposes are negative stimu-
li, induce inflammation, and spacelus by oxyd-
ing the fibre ? Where then is the positive stimi-
lus to produce the infiammatio n ? Or must we
suppose the oxygene acts on itself? As those
seem to think who believe it to be not only
the principle of irritability,  but the agent that
acts on it! !  A negative stimulus, one  would
naturally  suppose,  when taken  into  the  sto-
mach,  would cause an accumulation of irrita-
bility in the whole of that organ ; and the ac-
tion of any stimulus would produce a general
inflammation.  But the  fact is,  that in  death
from arsenic, the inflammation is nearly limit-
ed to  the spot  in  contact  with  the  arsenic,
which  is generally gangrenous.   And further,
we know that the use of the oxygenated muri- 
                 (  19   )
ate of Potash, several of the acids, and many o-
ther substances, that contain more oxygene,
and  part with it more readily,  have none  of
these effects.   Even the breathing of pure oxy-
genous gas, but gently increases the heat of
the body, without inducing any kind of inflam-
mation.—

   The 3d axiom I believe to be equally false
with the 2d.  In it, he asserts, that all substan-
ces are stimulating in proportion to their great-
er, or lesser affinity for the oxygene of the irri-
table fibre; and that the  action of the  living
fibre, is the effect of the combination of its oxy-
gene with the stimulating substance.  Here I
would ask, is it likely, that pieces of broken
glass,  particles of sand,  thorns  or  pins,  all
which stimulate when they come in contact
with the irritable fibre, induce action, pain and
inflammation, by combining with its oxygene,
by a superior chemical affinity ? Can any proof
be given  of  their having suffered a chemical
change ?  Does volition combine with the oxy-
gene of tlu  muscles of our limbs when  we
choose to walk ? Is it probable, that the dead-
ly poisons, from the animal or vegetable king-
 dom, which when applied in a very small quan-
 tity to any part of the body, destroy instantane-
 ously the irritability of the whole system, thus 
                  (   20  )
 annihilate life, by combining with all the oxy-
 gene of the irritable fibres ? We have no evi-
 dence of such strange effects from the affinities,
 as Gertanner supposes here.  And if  it were
 even possible for us to see the operation going
 on, we would find it difficult to credit our sen-
 ses. The ingenious professor Barton, has as-
 certained by experiment that camphor increas-
 es the life and irritability of plants.  The effect
 was permanent.  Many other substances which
 are not supposed to contain oxygene, act very
 powerfully  in  restoring and augmenting the
 irritability,  of both plants and animals.  Pro-
fessor Humboldt has proved, by a great variety
 of ingenious and well conducted experiments,
made on the hearts,  and other irritable parts
of animals,  that oxygene is not the irritable
 principle ;  for that the irritability of the fibre
may be increased,  and renewed by substances,
which do not contain oxygene ;  and  even af-
ter the application of oxygene had ceased to
produce any effect.  Some of these  substan-
ces are  electricity,  the  alkalies, phosphorus,
opium, and hydrogene.   I have repeated seve-
 ral of his experiments myself, and have found
precisely the the same results.—

  Oxygene  possesses the capacity to be acted
on by the lungs, and  assimilative powers of
animals, as  carbonic acid gas, and  nitrogene 
                  (   21  )
do by vegetables.  Oxygene is to be consider-
ed in the same point of view then as any other
nutricious substance.   Which substances are
salutary, only so long as the principle of life
has the power of acting on them.   If the  or-
gans were dead, all the oxygene in the universe
would be insufficient  to produce vitality in the
human frame.  Nay, if the chemical action,
which  it is  supposed oxygene exerts on the
system, to produce life, did really take place,
death,  disorganization, and  decomposition,
would be the inevitable consequence.  To say
that oxygene is the principle of life or irritabi-
lity, because its presence is necessary to the a-
nimal economy, is a very unphilosophical  de-
duction.   It might as well be said, that water,
lime, iron, azote, and carbone, were the prin-
ciples of life ; for their presence is equally ne-
cessary in the animal body.  Oxygene, when
vitalized and assimilated to the blood, appears
to constitute the means, by  which it  is fitted
to be conveyed by the vascular system, to the
different parts of the  body.  But this does not
make it the principle of life.   For  water  and
caloric, are equally necessary for this purpose.
Some have supposed that it creates life, in  so
far as it acts as a  stimulus.   If this were true,
it still would not constitute the principle of life, 
                 (  22   )
for we would have fifty others, as alcohol, opi-
um, azote, &c.

   It may now be deemed incumbent on me to
state, what I believe to be the efficient cause
of life.  I will take the liberty here to assert,
that all the phenomena of life and motion, are
owing to the energy of a  subtile, active prin-
ciple, called the electric fluid : which fills the
immensity of space, actuates  every particle of
matter, and is the universal principle of anima-
tion and motion.  Although this may be deem-
ed an absurd hypothesis, both by the oxygen-
ous philosopher,  and the mechanical theorist
of life, yet, by attending to the records of phi-
losophy, we will find, that it has been held un-
der one form or other by the greatest and wis-
est men in all ages.

   Pythagoras admitted  one primary   active
principle,  which he  called a subtile fire,  or
aether :  this he  asserts  animates all  things,
and  is the efficient cause of motion.   Hera-
clitus maintained that fire,  or the aethcrial
principle  which  pervades and  animates the
universe, has within itself eternal and necessa-
ry motion, by the energy of which, all  the
forms of nature are  produced.  Plato asserts,
that the anima mundi, (                    ) 
                 (  23  )
is the cause or principle of motion  (
         ), this  anima mundi he describes as
a fiery principle, essentially active.   Aristotle
maintains that animal heat, (
       ) of which he expressly says all things
are full, is the universal vital principle. Indeed,
almost all the ancient philosophers held  the
existence of a subtile, aetherial, fiery principle,
which is essentially  active,  pervades the uni-
verse, and is the efficient cause of animation,
organization and motion.   The Pythagoreans,
Stoics, Platonists and Peripatetics, called this
principle plastic nature.   Many  celebrated
modern characters have assumed this princi-
ple, as Berkeley, Harris, Cudworth, Monro,
Young, and many others.  Newton ascribes the
 same properties to his aether, that the ancients
did to their plastic nature.   The late import-
 ant discoveries in electricity,  have shown this
 plastic nature, to be one and the same with
 the electric fluid.

   The matter of galvanism, magnetism, elec-
 tricity,  heat and light, appear to be  only  mo-
 difications  of one  and the  same  elementary
 principle, which may  be called the electric
 fluid. " Entia non  sunt  multiplicanda absque
 necessitate." According to Boscovich, life, or-
 ganization and motion, are the effects of attrac- 
                 (  24   )
tion and repulsion.   The electric fluid is now
acknowledged to be the universal principle of
attraction and repulsion,  and of course of all
the phenomena of nature.

   Many arguments and facts might be adduc-
ed to prove the- electric fluid to be the univer-
sal principle of animation and motion, did not
the limits I have prescribed to this imperfect
essay preclude them.
FINIS. 
 
 
Me-dL. Hist,

  3/70
MITHu 
ti  fai
=sstt
t-f^f

:,A
*""l  .
L#'