A CHEMICAL STUDY OF THE SECRETION OF 
THE ANAL GLANDS OF MEPHITIS ME- 
PHITICA (COMMON SKUNK), WITH RE- 
MARKS ON THE PHYSIOLOGICAL PROP- 
ERTIES OF THIS SECRETION 
BY 
THOMAS B. ALDRICH, Ph. D. 
From 
' HE JOURNAL OF EXPERIMENTAL MEDICINE 
Vol. I, No, a, 1896 A CHEMICAL STUDY OF THE SECRETION OF THE 
ANAL GLANDS OF MEPHITIS MEPHITICA (COM- 
MON SKUNK), WITH REMARKS ON THE PHYSIO- 
LOGICAL PROPERTIES OF THIS SECRETION. 
{From the Laboratory of Physiological Chemistry of the Johns Hopkins University.) 
THOMAS B. ALDEICH, Ph. D. 
The subfamily Mephitince, to which the skunk belongs, is repre- 
sented in the United States by three genera : Spilogale, Conepatus, 
and Mephitis. Mephitis includes all of the large common skunks 
of the United States except the so-called ‘‘badger” skunks along 
our Southern boundary, which belong to the genus Conepatus. 
Three species are referred to Mephitis : M. macrura, M. putorius, 
and M. mephitica. The latter species is found from Hudson’s Bay 
to Guatemala, but is more frequently met with in the Northern and 
Eastern States. 
Before considering the secretion itself it will be well to describe 
briefly the anal glands or pouches, common not only to the sub- 
family Mephitince, but also to the family Mustilidce. The two 
pouches in which is secreted the fluid emitting the offensive odour 
that has made the skunk notorious are situated on either side of the 
rectum close to the anus. They are oval in shape, the longer diam- 
eter from an inch to an inch and a half, surrounded by a muscular 
envelope and opening into the rectum just inside the sphincter by 
single ducts which terminate at the top of prominent nipplelike 
papillae. The papillae are situated at the bottom of recesses, and 
when not protruded are nearly concealed from view by folds of the 
mucous membrane. By gentle pressure the fluid in the sac may be 
forced out through the duct in a very fine stream. 
There is still prevalent an erroneous idea that the secretion is 
identical with the urine or is in some way connected with it. That 
Copyright, 1896, by D. Appleton and Company. 2 
The Secretion of the Anal Glands of Mephitis Mephitica 
there is no connection whatever between the sacs and the <mnito- 
urinary passages has been shown by Wyman* and Chatin.f The 
latter especially has made a thorough anatomical study of the anal 
glands of Conepatus mapurito. His observations may be summed 
up as follows : Below the muscular layer—that is to say, within the 
general muscular envelope—is found the follicular or glandular 
portion proper of the organ ; it is not regularly distributed around 
the central reservoir, as in most carnivora, but occupies only a 
limited portion of the surface of the receptacle. The follicles are 
rather large and of a reddish-brown colour; their numerous well- 
developed culs-de-sac measure on an average 055 millimetre in 
diameter, and are variously rounded, ovoidal, club-shaped, etc. The 
reservoir is lined with a comparatively thick wdiitish tunic composed 
of dense laminated tissue and elastic tibres. 
Dr. L. F. Barker, Associate in Anatomy in the Johns Hopkins 
University, has kindly furnished me with the following analysis of 
a series of sections from tissues obtained from the common skunk, 
which were prepared for me in the Pathological Laboratory by Dr. 
George W. Dobbin : 
“ The sections go through the wall of the sac in different parts, 
and have been stained in hsematoxylin and eosin. The wall consists 
of an internal mucous membrane, a submucous coat, a muscular coat 
of striped fibres, and an external fibrous coat. The masses of glands 
are situated in the submucosa. Leading from the reservoir to the 
outside is a duct lined by stratified epithelium which opens at the 
apex of the papilla or nipple. 
“ Tunica Externa.—This is thin, consisting of fibrous tissue poor 
in cells. A fewr fat-cells are present in places, and large veins are 
met with in transverse and longitudinal section. 
“ Tunica Muscularis.—The muscular coat varies considerably in 
thickness, being about four millimetres in its thickest part and one 
millimetre in its thinnest part. It consists .of bundles of long striated 
muscle fibres, which in places run all in one direction ; at other parts of 
* Proc. Boston Soc. of Nat. Hist., 1844, i, p. 110. 
f Ann. des Sciences nat. [s], 18*74, xix, p. 100. Thomas B. Aldrich 
3 
the wall the fibres of the outer part run at right angles to those of the 
inner. The individual muscle fibres are of large size, are exquisitely 
cross-striated, and show spindle-shaped nuclei in the periphery of the 
fibre quite like those of human muscle. The internal perimysium 
carrying blood vessels is everywhere delicate. 
uTela Suhmucosa.—This consists of a .rather loose mesh work of 
fibrous tissue intervening between the mucous membrane and the 
muscle. In it are situated the masses of glands. These are not 
evenly distributed throughout the wall of the sac, but occur in 
masses in various parts, being particularly abundant at the fundus 
of the reservoir. In the submucosa, arteries of medium size and 
larger veins are situated; and near the glands, between them and 
the muscle, bundles of raedullated nerve fibres of considerable size 
are to be made out. 
“The masses of glands themselves showT gland tubes cut in vari- 
ous directions transversely, longitudinally, and obliquely. They ap- 
pear to be coil glands, although they may branch. The amount of 
connective tissue between the coils is insignificant, there being just 
enough to carry a rich supply of blood capillaries. Sections of the 
glands show the tubules to be lined by cubical epithelium; the 
nuclei of the cells are situated rather nearer the proximal than the 
distal ends of the cells. They are round, or slightly oval, and stain 
intensely in hseraatoxylin. The distal portion of the protoplasm 
stains rather more feebly than the proximal portion, the latter taking 
a deeper tint in hsematoxylin and tending to be slightly granular. 
The lumen of the tubule varies in different parts. In places it is 
wide, in other places reduced to a narrow slit. Between the proxi- 
mal ends of the epithelial cells and the basement membrane long, 
spindle-shaped nuclei can be seen whose long axis is, as a rule, paral- 
lel to the course of the gland tubule. These are evidently the nuclei 
of smooth muscle fibres. The basement membrane itself appears 
delicate and homogeneous. Here and there within a mass of tubules 
an artery or vein of considerable size may be met with. 
“ Tunica Mucosa.—This consists of an epithelial covering and a 
tunica propria. The epithelial covering consists of several layers of 4 
The Secretion of the A not Glands of Mephitis Mephitica 
epithelial cells, the deepest layers tending to be cubical, the more 
distant layers to be polyhedral in shape. As a rule, the layer is 
from four to five cells deep. All of the cells distal to the proximal 
row show a network within the cell protoplasm, the meshes of which 
are filled up by clear hyaline droplets. The appearances in these 
cells resemble very closely those to be seen in the cells of sebaceous 
glands. 
“ The superficial cells of the epithelial layer may be nucleated or 
non-nncleated, and in this layer the protoplasm contains large num- 
bers of irregular masses and particles which stain deeply in hema- 
toxylin, but metachromatically, taking a reddish-brown tint. These 
particles resemble closely those seen in the granular cells at the 
periphery of the stratum germinativum (Malpighii) in human skin 
(kerato-hyalin—Waldeyer). In places on the surface or desqua- 
mated from it can be seen a layer of cells which hang together, 
which are almost entirely devoid of chromatic substance and look 
like pale vesicles united edge to edge. 
“ The tunica propria of the mucous membrane is a little less than 
1 millimetre in thickness, and consists of bundles of white fibres 
which for the most part run parallel to one another, taking a some- 
what wavy course, Nuclei of connective-tissue corpuscles are visible 
between the bundles, and small blood vessels are also present in this 
layer. There are no distinct papillae to be made out in the wall of 
the reservoir, although they are present in the duct leading from the 
reservoir through the papilla to its apex. 
“ The Papilla or Nipple.—ln transverse section this is seen to 
be lined by stratified epithelium resting upon a distinctly papillated 
tunica propria. The papilla is rich in voluntary muscle fibres, the 
mucous membrane lining it being surrounded by two rows of bun- 
dles of fibres which run parallel to the long axis of the duct. Exter- 
nal to these is a tolerably thick layer of muscle fibres which run for 
the most part circularly, although some of them run obliquely. No- 
where in the papilla or in the reservoir can smooth muscle be made 
out except, as before described, in the structure of the glands them- 
selves. Outside the voluntary muscle of the papilla is a firm fibrous Thomas B. Aldrich 
5 
coat. In the connective tissue of the papilla and here and there 
among the epithelial cells branched pigment cells are visible. 
“ The histologist must be struck by the resemblance of the struc- 
ture of the glands in the wall of the reservoir to that of the ordinary 
sudoriferous glands of the skin. Indeed, it is not inconceivable that 
these glands of the skunk may represent curiously modified sweat 
glands. As to the nature of the reservoir with its curious epithelial 
lining, it is difficult to decide. If the glands in the wall of the 
reservoir of the skunk should turn out to be homologous with sweat 
glands, the relation of the reservoir to sweat pores will have to be 
considered. In this connection, the curious character of the epithe- 
lium cells lining the reservoir, reminding one somewhat of the struc- 
ture seen in sebaceous glands, must not be forgotten ; and any at- 
tempt to explain the origin and the character of the secretion should 
consider not only the products of the glands in the submucosa, but 
also the part, if any, played in its formation by the epithelium of the 
reservoir itself.” 
The exceedingly disagreeable odour possessed by the secre- 
tion of the Mephitince,* and the difficulty attending its collection in 
sufficient quantity for an exhaustive study have deterred investi- 
gators in the past from studying this most singular and interesting 
fluid. 
If one were bold enough to start the investigation, objections 
were invariably raised, and thus all further research was stopped. 
At least this was Loew’s f experience, who says : “ On an expedition 
through Texas in 1872 I had frequent opportunity to collect a suffi- 
cient quantity of this secretion to establish its chemical constitution, 
but all my companions protested against it, declaring the odour 
which clung to me to be unbearable. On my return to Hew York 
city I started a few chemical tests, with the little I had collected, 
when the whole college rose in revolt, shouting, £ A skunk, a skunk 
* I am informed by Dr. 0. Hart Merriam, Chief of the Division of Mammalogy and 
Ornithology, Washington, D. C., that the secretion of some other members of the family 
Mustilidce is, if possible, more offensive than that of the skunk. The secretion of the mink 
is not so diffusible or penetrating, but it is more nauseating. 
f Aerztliches Intelligenzblatt von Munchen, June 10, 1879, p. 252. 6 
The Secretion of the Anal Glands of Mephitis Mephitica 
is here ! ’ I had to abandon the investigation.” * This, no donbt, 
has been the experience of others who have attempted to study 
either the secretion or the glands. I have been more fortunate than 
my predecessors in being surrounded by those who, for the cause of 
science, would endure even the odour of a skunk in close proximity. 
Had it not been for this forbearance on their part, I should un- 
doubtedly have suffered the fate of others. 
Lassaigne,f Swarts £ (in Wohler’s Laboratory), and Loew # have 
all made the secretion of the skunk the subject of chemical research, 
but it is to be regretted that the origin of the fluid investigated by 
the two former was unknown. | 
Lassaigne separated the secretion into a heavy and a light oil. 
Swarts found it to consist of a colourless portion boiling between 
105° and 110° C., and a heavy yellow oil boiling between 195° and 
200° C. In the residue he recognised a nitrogenous basic body 
wdiich, from its volatility, he concluded to be either methylamine or 
ethylamine. 
According to Loew, the secretion consists of at least two bodies, 
one of which is richer in sulphur than the other, possesses properties 
similar to the oil obtained from garlic (.Knohlauchol), gives with the 
metals salts, and is violently attacked by concentrated nitric acid; 
the other oil contains nitrogen and gives rise, under certain condi- 
tions, to a base which smells like trimethylamine. 
The results of these investigators amount to very little from a 
chemical point of view. Nothing definite as to the real chemical 
nature of this secretion has hitherto been determined. 
The material for this investigation was obtained principally from 
the State of Maine; a small quantity, however, came from Long 
Island. With one exception, it came in the sacs, which were emp- 
tied as soon as received. The quantity of fluid in the sacs varies 
* From a letter to Prof. Abel, 
f Cited by Swarts. 
\ Liebig’s Annalen, 1862, cxxvii, p. 266. 
# Op. cit., p. 252. 
|| It is very probable that the secretion of the other members of the subfamily Mephitince 
differs very little from that of M. mephitica. Thomas B. Aldrich 
7 
greatly; some were found empty, others contained as much as 5 
cubic centimetres, or even more if they were very much distended. 
I presume the age, vigour, and size of the animal, also the method 
employed in capturing, will explain this variation. 
The length of time that elapsed before the sacs reached the labo- 
ratory varied from twelve hours to several days. In those cases 
where no especial care had been taken to prevent decomposition 
the sacs still gave no evidence of change. It is probable that the 
secretion preserves from immediate decomposition not only the tissue 
in contact with it, but also that in the immediate neighbourhood. 
ISTo differences that could be attributed to decomposition were ob- 
served in any case, the odour and colour of the secretion from the 
different sacs being approximately the same. 
Physical Properties of the Fluid. 
Obtained from the sacs a few hours after the death of the ani- 
mal, the secretion is a clear, limpid fluid, of a golden-yellow or light- 
amber colour, of a characteristic, penetrating, and most powerful 
odour, and having a specific gravity, at ordinary temperature, less 
than water (0'939). 
The fluid filters readily, sometimes shows a decided greenish 
cast, and in the evening is said to be slightly luminous; but I my- 
self have not been able to verify the last observation. After removal 
from the sac it turns gradually darker in colour, probably on account 
of a slight oxidation. It remains fluid at a temperature of —l3° C. 
There is generally present in the sacs to the extent of one 
gramme or more a yellowish amorphous body, having, as far as I 
have tested, an alkaline reaction, and giving the proteid tests. I 
take this substance to consist in large part of the debris of desqua- 
mated epithelial cells from the inner surface of the sac. Whether 
any chemical function is to be ascribed to this debris I have not yet 
been able to determine. Prismatic crystals have been observed 
when a little of the fluid has remained some time in contact with the 
amorphous body referred to. The secretion standing in a bottle often 
deposits a white flocculent substance. 8 
The Secretion of the Anal Glands of Mephitis Mephitica 
Chemical Peopeeties of the Fluid. 
The reaction of the fluid I found to be neutral; others have found 
it intensely acid ; * but I can not reconcile this statement with the 
character of the chemical bodies found in the secretion. These sub- 
stances without doubt belong to groups that have as one of their 
characteristic properties a neutral reaction. 
The vapours of the fluid are highly inflammable and burn with a 
luminous flame, giving off sulphur dioxide. 
Absolute alcohol, ether, and chloroform dissolve the fluid readily. 
Concentrated sulphuric acid dissolves it, but not without producing 
some changes, as the colour changes to a deeper hue. The body is 
thrown out of the alcoholic and concentrated sulphuric-acid solu- 
tions on dilution with water, in which it is practically insoluble. 
The odour in these solutions is but little changed. 
A fifty-per-cent solution of sodium or potassium hydroxide dis- 
solves the fluid partially, the peculiar odour disappearing almost en- 
tirely. From this solution the oil is liberated on dilution with much 
water ; the addition of dilute sulphuric acid brings bach the original 
odour. The same facts may be shown in the following way: 
A strip of filter paper moistened with an aqueous solution of lead 
acetate and suspended over the natural secretion takes on a bright- 
yellow colour; held over the secretion that has been dissolved in a 
fifty-per-cent solution of potassium hydroxide, no change is noticed, 
though it may be in time somewhat darkened in colour ; but if this 
potassium-hydroxide solution is acidified by the addition of sulphuric 
acid, the bright-yellow colour is again seen in the filter paper held 
over it. Paper moistened with copper sulphate is acted on in the 
same way, only that the colour is not so pronounced. 
The dilute sulphuric-acid solution, or the aqueous solution, for it 
is soluble to a slight extent in water, reacts toward an iodine solu- 
tion similarly to the corresponding solutions of alkyl-sulphides.f 
Bromine acts like iodine. 
* Merriam. Mammals of the Adirondacks, p. 'ZB. 
f Abel. Zeit.f. physiol. Client., xx, pp, 2'71-2'73. Thomas B. Aldrich 
9 
An alcoholic solution of the secretion gives with alcoholic solu- 
tions of lead acetate, mercuric cyanide, mercuric, platinic, or auric 
chloride, for the most part amorphous precipitates. The lead com- 
pound is yellow in colour, the mercuric compounds are white, and 
the platinic and gold chloride compounds are orange. Mercuric 
oxide reacts either directly in the fluid, or in an ethereal solution of 
the same very energetically, as does also concentrated nitric acid; 
both form crystalline compounds. An alcoholic solution of ferric 
chloride gives with the corresponding solution of the secretion a 
light-green colour. 
These physical and chemical properties just referred to warrant 
the assertion that one or more raercaptans, or thioalcohols, are pres- 
ent in the secretion. 
Fractional Separation of the Secretion. 
Being convinced of the presence of raercaptans in the secretion, 
fractional distillation suggested itself as the best method to use in 
their separation. Accordingly, the filtered secretion was distilled 
from a suitable bath. With the mercury completely in vapour, a 
clear, colourless fluid constituting about half of the secretion, dis- 
tilled over between 100° and 130° C. The bath temperature was 
generally about 130°, never over 150° C. The temperature then 
fell, though the bath temperature was increased to 180° C. As 
there was no evidence of decomposition, it is natural to suppose that 
these bodies are in the original secretion, and not decomposition 
products. By this method we are enabled to separate the secretion 
into two sharply defined and nearly equal portions: 
1, The more volatile portion, boiling between 100° and 130° C., 
and which for convenience we will designate A, 
2. The less volatile portion, left after distilling off A, and which 
we will call B. 
An apparatus so arranged as to detect any gas that might be 
given off under 100° C. gave a negative result. The three lower 
raercaptans—methyl (B, F.), 6° ; ethyl (B. F.), 36° ; normal propyl 
(B. P.), 67°; and iso-propyl (B. P.), 57° to 60° C.—were thus 10 
The Secretion of the Anal Glands of Mephitis Mephitica 
shown to be, in all probability, absent. We are therefore compelled 
to seek our mercaptans among those with boiling point near or over 
100° and still under 130° 0. 
Fraction A. 
A is a mobile colourless fluid lighter than water and having a 
very unpleasant penetrating odour, scarcely to be distinguished 
from that of the original secretion. It gives, without exception, all 
of the reactions of the original secretion. 
After drying over calcium chloride for twenty-four hours it was 
distilled fractionally. Three fractions were obtained : 
1. a, boiling between 100° and 110° C. and constituting about 
one half of A. 
2. /3, boiling between 110° and 120° and constituting one fourth 
of A. 
3. 7, left in the bulb after distilling off the two former and con- 
stituting one fourth of A. 
These three fractions—a, /3, and 7—give the mercaptan reactions ; 
that is, they unite with mercuric oxide, mercuric cyanide, and lead 
acetate to form compounds characteristic of the mercaptans. /3 was 
found to contain less sulphur than a, a result to be expected if a 
higher mercaptan were present. For the purpose of identifying the 
mercaptan in fraction a, several analyses were made. 
Sulphur Analysis. 
A quantitative determination, according to Carius, of the per- 
centage of sulphur gave the following results : 
I. 0'1535 gramme gave 0-3955 gramme BaSO*. 
11. 0-2453 “ “ 0-6250 
Calculated for Pound. 
C4II9SH. I. 11. 
S 35-55 per cent. 35-St per cent. 34■ 98 per cent. 
In each analysis the sulphur is found too low. This may be 
readily explained by assuming the presence in small quantity of 
either amyl mercaptan, the sulphur contents of which are about 
thirty-three per cent, or of one of the higher sulphides. Thomas B. Aldrich 
11 
Lead Butyl Mercaptide, (C4HaS)2Pb. 
This compound was prepared by adding an excess of a saturated 
alcoholic solution of lead acetate to the alcoholic solution of the 
fraction a. It was obtained in beautiful glistening, yellow, rhombic 
plates, which, recrystallized from alcohol, washed with alcohol and 
ether, and dried in vacuo over sulphuric acid, gave the melting point 
85° to 90° C. The compound is very unstable, decomposing readily 
into the corresponding mercaptan and sulphide of the metal. Possi- 
bly this instability may explain the great range of its melting point. 
Dilute hydrochloric acid as well as dilute sulphuric acid decom- 
poses it, and more readily on heating. Prepared as given above, 
carbon, hydrogen, and lead determinations were made: 
I. 
0-2255 
gramme gave 
0-2106 
gramme 
C02 and 0-0802 gramme H20.* 
II. 
0-2453 
u u 
0-22'7'Z 
u 
U U 
0-0858 
u u * 
I. 
0-2033 
u a 
0-1584 
u 
PbS04 = 
53 • 22 per cent of Pb. 
II. 
0-1265 
a a 
0-09Y4 
u 
“ = 
53-02 
u u 
Calculated for 
Found. 
(C4H#S)aPb. 
I. 
II. 
C 
25 
•00 
25-45* 
25-31* 
H 
4 
•68 
3-95* 
3-89* 
Pb 
53 
•64 
53-22 
53-02 
This body is precipitated as an amorphous compound, though 
Mercuric Chloride Butyl Mercaptide, (C4H9S.IIgCI). 
inclined to crystallize, when alcoholic solutions of mercuric chloride 
and of fraction a are brought together. It is practically insoluble 
in cold alcohol, sparingly soluble in hot, from which it crystallizes 
in glistening white plates. Recrystallized from hot alcohol three 
times and dried in vacuo over sulphuric acid, it decomposes partially 
without melting when heated to 185° C. This compound, being stable 
in the air and having been recrystallized a number of times, gave 
results which compare more favourably with the theoretical figures. 
I. 0"2'746 gramme gave 0*1963 gramme of HgS = 61-62 per cent, of Hg. 
11. 0-1658 “ “ 0-1192 “ “ =6l-94 “ “ 
Calculated for Found. 
C 4H9S.HgCI. I. n. 
Hg 61-63 61-62 61'94 
* These results were obtained from the analyses of the lead mercaptide prepared as 
described on page 335 12 
The Secretion of the Anal Glands of Mephitis Mephitica 
Mercuric Butyl Mercaptide, (C4H9S)aHg. 
When mercuric oxide is added to either a or its ethereal solution 
energetic reaction takes place, the oxide disappears, and a white, for 
the most part amorphous body, somewhat soluble in ether, is depos- 
ited. It can be crystallized from its ethereal solution and obtained 
in white rhombic plates. After having been dried in vacuo over 
sulphuric acid, it melted sharply at 94° to 95° C. to a clear colour- 
less fluid. On cooling it solidified to a mass of crystals. 
This compound, like most of the metallic derivatives of the 
mercaptans, decomposes readily; even during the process of recrys- 
tallization from ether, partial decomposition takes place; it turns 
gradually dark when kept for some time. 
0" 1108 gramme gave 0" 1053 gramme C02 and 0-0386 gramme H20. 
Calculated for 
(C4H98)2Hg. Found. 
C 25-40 25-90 
H 4-'76 3-88 
The difficulty of making a carbon determination directly with 
the fraction a will be understood when it is known that a portion of 
the carbon is deposited in the glass bulb before the entire fluid has 
volatilized. It was thus found impossible to burn all of the carbon. 
The results of these analyses are sufficiently near the theoretical 
figures when considered together with the boiling point of a to con- 
vince, 1 think, the most sceptical that the greater part of this frac- 
tion contains one of the butyl mercaptans. 
Primary normal butyl mercaptan is given as boiling at 97° C.* 
The boiling of a. between 100° and 110° C. could be easily explained 
if we assume the presence in small quantity of some higher boiling 
body. This assumption would also explain in general the analytical 
results. lam inclined to believe in the presence of a higher mer- 
captan (say amyl mercaptan) rather than a sulphide. The other 
fraction of A will be taken up at some future time. 
After the above analyses had been made I was fortunate enough 
* When the mercury is completely in the vapour it will be found to boil a few degrees 
above 97°. Thomas B. Aldrich 
13 
to obtain a larger quantity of the secretion. This I treated in the 
manner already described as far as the separation of A and B is 
concerned. From this point A was not at first subjected to fraction- 
al distillation, but shaken up with a fifty-per-cent solution of potas- 
sium hydroxide in order to dissolve out the mercaptans, and then 
repeatedly shaken out with ether to remove any body not soluble in 
alkali. The results show, however, that when the first distillation is 
conducted carefully, A is practically free from any bodies outside of 
the mercaptans, there being very little oil or residue left after the 
ethereal solution is allowed to evaporate. Dilute sulphuric acid was 
then added to the alkaline solution, keeping it in an ice mixture, 
and the mercaptans, free of any possible sulphides, collected with 
ether. This ethereal solution was dried over fused calcium chloride 
for twenty-four hours and then, after filtration, subjected to frac- 
tional distillation ; the same fractions were obtained as before; the 
boiling point and quantity of each fraction remained practically the 
same. 
For comparison, the mercuric mercaptide obtained by adding 
mercuric oxide to an ethereal solution of a was made and recrystal- 
lized from ether. Dried in the usual manner, the melting point was 
found to be the same as the mercaptide previously described—94° 
to 95° C. 
The lead mercaptide was also prepared in the usual manner and 
combustion analyses made. The results of these analyses have been 
already given under Lead Butyl Mercaptide, page 333. 
Synthetical Formation of the Higher Mercaptans. 
Several attempts were made to prepare synthetically a mercaptan 
having an odour and other properties similar to the fraction a or /3. 
The method employed was that used by Klason (.Berichte, xx, 
p. 3904). The alcohols used were iso-butyl alcohol and iso-amyl 
alcohol. The results obtained with iso-butyl alcohol were not satis- 
factory ; there appeared to be decomposition products formed when 
the alcohol was allowed to drop into the concentrated, and fuming 
sulphuric acid. The results obtained with iso-amyl alcohol, how- 14 
The Secretion of the Anal Glands of Mephitis Mephitica 
ever, were very satisfactory. About fifty grammes of pure iso-amyl 
mercaptan boiling between 115° and 120° C. were obtained which 
resembled in all outward appearances the fractions a and ft already 
described, and its odour in concentration or dilution was hardly to 
be distinguished from that of these fractions or from that of the 
original secretion. It gave the mercaptan reactions, and could not 
by any of these reactions be distinguished from the fractions a and 
ft of A. 
I intend in the near future to prepare the normal mercaptans of 
these higher alcohols and compare them with the fractions of A. 
Portion of the Secretion called B. 
B has a neutral reaction, a dark-red colour, and an aromatic and 
less penetrating odour than either A or the secretion. The origi- 
nal colour of the secretion can be nearly brought back by adding 
a volume of alcohol or ether to B equal to A. This seems to 
indicate that very little decomposition had taken place in distilling 
off A. 
B differs from A in containing nitrogen and in not reacting with 
mercuric oxide, mercuric cyanide, or lead acetate; it resembles Ain 
giving all the other tests referred to under the secretion. I therefore 
infer the absence of mercaptans from B. This inference was proved 
to be correct, for upon shaking B with a fifty-per-cent solution of 
potassium hydroxide, and subsequently acidifying and shaking out 
with ether, a trace of an oil was obtained which failed to give the 
mercaptan tests. 
The fact that B contains no mercaptans and still contains a large 
amount of sulphur, that it is insoluble in a fifty-per-cent solution of 
potassium hydroxide, that it reacts with mercuric chloride, also with 
iodine and bromine, and that it is violently attacked by concentrated 
nitric acid, justify me in predicting the presence of alkyl sulphides, 
or bodies closely related to them, in this portion of the secretion. I 
am inclined to believe, from certain tests that I have made, that 
these sulphur bodies are combined or mixed with some basic body 
containing nitrogen. Thomas B. Aldrich 
15 
B, together with a basic body isolated from it, will form the sub- 
ject of another article. . 
The Odour of the Secretion. 
It is hardly necessary to say that the odour of the secretion is 
exceedingly persistent, diffusible, and. penetrating. 
The essential principle in the secretion has been attributed to 
various substances, all yl sulphide and the lower mercaptans * being 
the ones usually suspected. 
The great diffusibility and the penetrating property of the secre- 
tion is due to fraction A—that is, to the mercaptans; the perma- 
nency of the odour of the secretion is attributable to B, which tends 
to retain A and at the same time to modify its odour. 
Amount or the Secretion that may be recognised by the 
Sense of Smell. 
In order to test the sensitiveness of the olfactory nerves toward 
the fraction a and thus establish its identity with the more volatile 
and objectionable portion of the secretion, and also its relation to the 
mercaptans, the following experiments were performed : 
A known weight of a was dissolved in 500 cubic centimetres of absolute 
alcohol. To 10 cubic centimetres of this solution another known quantity 
of alcohol was added, and from this last solution 2 or 3 cubic centimetres 
were taken, placed in a bottle similar to one used for washing gases, and 
blown out into a room by means of a bellows. Room capacity, 696 cubic 
metres. 
The weighing took place in another building far from the room used, 
and the person who manipulated the bellows and mixed the portion of a 
with the air in the room had not been in the building where the secretion 
was kept and the weighings made. The mixing was continued for at least 
ten minutes by using large pieces of stiff paper as fans. At a given signal 
persons who had not previously been near the substance entered the room. 
First Trial.—0T of a milligramme of a was mixed with the air of the 
room. The odour was very apparent to all on entering. My power to 
detect the mercaptans had, however, been so blunted by previous contact 
* M. v. Xencki u. N. Sieber, Sitzb. d. kais. Akad. in Wien, Mathem. Classe, Mai, 1891, 
xcviii Abth. 11. b., S. 1; Swarts, Leibig’s Anncden, 1862, cxxiii, S. 266. 16 
The Secretion of the Anal Glands of Mephitis Mephitica 
with the substance that I was unable to detect in this dilution any odour 
whatever, although I could still detect mere traces of other odoriferous 
bodies. OT of ,a milligramme diluted with 696 cubic metres of air allows 
ffoWoowo milligramme to each cubic centimetre. 
Second Trial.—o‘ol of a milligramme of a was distributed through the 
same room several days after the first trial and after the room had been 
thoroughly ventilated. The odour was faintly apparent to all on entering, 
but was not noticeable after they had remained even a short time in the 
room. After they had freed the nostrils of the odour in the open air they 
could again detect it on re-entering the room. In this trial the limit of 
dilution was approximately reached. In this dilution we have in every 
cubic centimetre owoitoodoo of a milligramme. Granting that 100 cubic 
centimetres of this air are necessary to make the odour evident in this dilu- 
tion, we are able to recognise approximately rro o o~ o off °f a milligramme of 
a and about four times that quantity of the secretion. 
E. Fisher * and Penzoldt have found by similar experiments that one is 
able to recognise °f a milligramme of ethyl mercaptan. These 
results prove the nose to be by far the most delicate testing apparatus 
known, for the smallest quantity of sodium that can be detected by the 
spectroscope is nearly two hundred and fifty times larger f than the 
amount required of ethyl mercaptan to rouse the sense of smell. 
The similarity of ethyl mercaptan and the fraction a is very striking in 
respect to ditfusibility and penetrating power, and it is no doubt this portion 
combined with the fractions (3 and y which gives the secretion its all-per- 
vading property. 
Lack of material has prevented the further study of the physiological 
properties of the secretion. I take the liberty, however, of presenting cer- 
tain facts that I have gathered from various sources in regard to these 
properties, in the hope that they will be of general interest. 
The substance is a powerful anaesthetic,£ and has also been used 
as an antispasmodic. When inhaled without the admixture of a 
large amount of air the victim loses consciousness, the temperature 
falls, the pulse slackens, and, if the inhalation were prolonged, the 
results would doubtless prove fatal. 
When recently ejected, the fumes from this liquid are overpower- 
ingly pungent and extremely irritating* to the air passages, and are 
said to be capable of producing oedema of the glottis. It is also said 
to be an efficacious remedy in certain spasmodic affections of the air 
* Liebig’s Annalen, 239, 131. 
f Victor Meyer u. Jacobsen, Lehrbuch der organ. Chemie, p. 225. 
\ Skunk Perfume as an Anaesthetic. Virginia Med. Month,, August, 1881 vol. viii. 
No. 5, pp. 359, 360. Thomas B. Aldrich 
17 
passages. If any of this fluid finds its way into the eye it produces 
intense pain and sets up acute conjunctivitis, which commonly runs 
its course in a week or ten days. Moreover, wTe have reliable ac- 
counts of the entire loss of vision from this cause. 
Swartsf complained while working with the secretion, especially 
when distilling with water vapour, of violent headaches and dysuria. 
His urine was voided with a burning sensation, and deposited a 
brown sediment which smelled like musk, as did also the urine. His 
perspiration for several days retained the odour of the secretion. 
Though 1 have worked with comparatively large quantities of the 
secretion and during a period of three months, I have failed to 
observe in myself the symptoms described by Swrarts. 
As far as the literature of this subject is known to me, the pres- 
ence of the higher mercaptans in the animal organism has never 
before been demonstrated. 
It is true that M. v. Nencki;}; has found methyl mercaptan in 
the urine of those who had partaken freely of asparagus, and also 
among the gases given off during the putrefactive decomposition of 
the proteid ; # and that methyl mercaptan has also been found in the 
urine as the product of a special bacterium,| and also among the 
gases of the large intestine;A but all of these mercaptans, with the 
exception of the one arising from the use of asparagus, owe their 
origin to the putrefactive decomposition of proteids. The mercap- 
tan in the skunk secretion, on the other hand, differs widely from 
the above, as far as its origin is concerned. It is without doubt a 
normal product of the cell activity of the gland. 
The secretion of M. mephitica is not only remarkable for the 
quantity (about thirty per cent) of sulphur which it contains, and for 
this sulphur being in an unoxidized condition, but for the light it 
throws on the normal sulphur metabolism of the animal organism. 
* Merriam, op. cii. \ Op. cit. 
t Archiv f, exp. Pathol, u. Pharmakol., Bd. xxviii, pp. 206-209. 
#M. v. Nencki u. N. Sieber. Monatsh. f. Chemie, Bd. x, pp. 526-531. 
1| Karpins. Virchow’s Archiv, Bd. cxxxi, pp. 210-222. 
AL. v. Nencki. Sitzh. d. kais. Akad. (Wien), Math.-Naturwiss. Classe, 111. Abth., 98, 
pp. 43V, 438. 18 
lhe Secretion of the Anal Glands of Mephitis Mephitica 
Abel* has isolated from the dog’s urine a substance (ethyl sulphide) 
closely related to those found in this secretion, and has expressed the 
belief, founded on certain experiments, that it is a normal product 
of cell activity and not a product of putrefactive decomposition in 
the intestine. My results supplement his and give another instance 
of a highly unoxidized sulphur compound which is formed in the 
breaking down of the proteid molecule, and which is protected in 
some way from oxidation, or if oxidized, is subsequently reduced. 
It is useless to speculate on the immediate forerunners of this 
substance or substances with the little knowledge we at present pos- 
sess. Further examination of this interesting secretion, and further 
knowledge of sulphur metabolism, are required before we can theo- 
rize with much profit. It would, however, be of general interest, 
and no doubt increase our knowledge in this direction, to examine 
the urine of the skunk and determine the condition of its sulphur 
contents, also to conduct a number of feeding experiments for the 
purpose of determining the changes in the sulphur contents of the 
secretion and of the urine. 
I will say in closing that after completing my investigation of 
the secretion I intend to carry on experiments along the lines just 
referred to. 
* ZeitscJir. f. physiol. Chem., Bd. xx, S. 253.