Fat colouring matter and water, 97.8
Organic tissue, 2.2
—————
100.0
No. 2, 997 grammes adipocire, gave twenty-seven residue, or per cent.
Fat colouring matter and water, 97.3
Organic tissue, 2.7
—————
100.0
The fats were then saponified with Potassa; No. 1 by Chevreul’s
process, and No. 2 by Heintz’s process with alcohol. The soaps were
precipitated several times, by solution of common salt; no ammonia nor
cholesterine were detected during the process; a heavy, flocculent
soap fell during the melting, which was examined, and found to be a
soap of alumina, oxide of iron and magnesia; probably from impurities
in the salt. No glycerine was present (by direct experiment) in either
of the specimens. An examination for volatile fatty acids, gave
negative results for number one, and a very slight trace in number two
of volatile fatty acids, acetic and butyric, and one or two minute
floating oil drops, most probably from the alcohol employed.
The fats thus obtained, were very dark in colour, and when cooled,
after being melted in a capsule on water, solidified with a smooth,
waxy surface, with the fibres of crystallization vertical. At the point
of crystallization, the expansion pushed up, and broke the soft cake of
fat in the centre. No. 1 weighed 237 and No. 2, 644 grammes.
No. 1, (the melting point of which was 57.5°, the solidifying point
52°) was melted with an equal weight of alcohol, and on cooling,
filtered and pressed; a very dark liquid ran through, a drop of which,
evaporated on a glass slide, gave dendritic, stellate, polarizable
crystals. To the residue weighing 177 grammes, 100 grammes of
alcohol were added, and the fat which separated, together with some
depositing from the last filtrate by standing, were added to the
fat of the previous operation; the fat which separated from this
solution of 177 grammes, melted at 59°-60°, and solidified at 53°-54°.
The dark-coloured alcoholic liquid, filtered from these fats, was
saponified by an alcoholic solution of potassa; the alcohol expelled
by boiling with water, and after transferring to a retort, was boiled
with sulphuric acid. The distilled water, examined for volatile fatty
acids, gave negative results. The fat was very dark in colour, melted
at 55°, and solidified at 50°, though it was difficult to determine
these points exactly, as the change exhibited itself very gradually. A
portion of this fat was converted into a potassa salt, and precipitated
by chloride of barium; the filtrate from which, treated with
hydrochloric acid, gave a small quantity of a yellow fat, not further
examined.
The baryta salts were treated by ether, and the residue by boiling
alcohol. The ethereal, alcoholic solutions, and the residue, were
severally decomposed by hydrochloric acid. The ethereal solution gave
a small quantity of oleic acid, in very dark drops. The alcoholic
solution fat was also small in quantity, and dark. It fused at 61°-62°,
and solidified, as well as could be judged, at 45°. The residual fat,
which was the largest in quantity, yellow, and of a waxy surface,
melted at 43°-46°, and solidified at 45°-40°.
The purification of fat No. 2, was now undertaken, and experimented
upon more particularly than No. 1, since this specimen of adipocire
conformed to the shape of part of the human frame.
1^o. An equal weight of alcohol was added, and the fat, which weighed
644 grammes, was dissolved by heat; on cooling it was pressed, and as
the filtrate deposited more fat on standing, it was pressed again, and
the fat added to the former. The dark-coloured filtrate was bottled,
and the fat melted. It was of smooth and waxy surface, and weighed 511
grammes.
2^o. The fat from 1^o was melted with 170 alcohol, and the same
operation performed. Residue weighed 327 grammes.
3^o. Added 124 alcohol to this fat. In this all the liquor was absorbed
by the pressing cloths; the fat weighed 335 grammes.
4^o. Added an equal weight of alcohol and melted; pressed after two
days. The liquid by this time, was light yellowish; the fatty crystals
in white flakes or scales; the smaller ones transparent under the
microscope, and polarizable. A portion of the fat was melted, and
observed cooling under the microscope with polarized light; as the
solidification approached, a beautiful play of prismatic colours took
place, and the drop shot into crystal interlaced lamellæ. A drop
melted with alcohol, and let cool, gave the peculiar dendritic curved
appearance of margaric acid.
5^o. The fat by this time weighed 300 grammes; it was melted with an
equal weight of alcohol, and pressed the following day. Residue, 253
grammes.
6^o. This was melted with 250 alcohol; the liquid from the press was
very little less coloured than the last; the residue weighed 227
grammes, and was brilliant white, with a tinge of yellow; the fracture
showed large crystals, and could not be distinguished from the product
of the stearic candle factories. When melted, it cooled with raised,
uneven surface, and was completely soluble in ether. When the ethereal
solution was suffered to separate spontaneously, the first fat which
made its appearance melted at 60°, solidified at 55°, and the fat
extracted from the rest of the ether gave exactly the same points.
The following are the melting points yielded by the fatty residues of
the foregoing alcoholic crystallizations:
Fat melts solidifies
2^o 58° 53°
3^o 58° 53° a 52°
4^o 58° 53° a 52°
5^o 58° a 58.5° 53°
6^o 60° 55° a 54°
The examination of the liquids separated from the above
crystallizations, was now taken up. Their colour was from a very deep
reddish brown (No. 1^o) down to light yellow, and nearly colourless
(No. 6^o.) In 1^o, 2^o, and 5^o, crystals had deposited by standing,
and as 2^o was not corked like the rest, the deposit here was abundant;
it was re-melted with addition of as much alcohol as had evaporated,
and was suffered to stand for several days longer, when a drusy
crystalline deposit made its appearance. The following are the melting
points for these two precipitates:
Precipitate in 1^o melts 62°-63° solidifies 44°5-40°
Precipitate in 5^o melts 51°-56° solidifies 44°5-43°
The fat deposited in 2^o melted at 58°, and solidified at 52°, and
the fat separated from the _liquid_ of this bottle, melted at 59°5,
solidified at 53°, but continued translucent down to 33°. After the
above melting points, 1^o and 5^o were observed, the same fat was
raised slowly to the melting points, and then kept for a considerable
time in the thermostat, at 100°, the points were again determined, and
found to be the same.
The liquids separated from the fats 1^o-6^o, gave the following results:
The fat from Liquid melts solidifies
1^o 36°-46° 41°-?
2^o 39°-41° 37°-35.5°
4^o[6] 59°-62° 40.5°-35°
5^o 62°-66° 58°-53°
6^o 53°-56° 41°-?
The melting point of liquid 2^o, does not accord with that above
stated, but I note the experiments as they were observed, merely
mentioning that I observed carefully, and am not conscious of having
made an error. The above points seem vague, but it was impossible to
fix a point definitely, as a cloudiness persisted up to the highest
degree stated, so I prefer to give the limits of certainty. In 1^o and
6^o the solidifying points, 41°, were taken when the liquid in the
capillary tubes seemed to become solid, but it remained translucent
for a long time below this point, and 6^o only became opaque (and that
gradually) when suffered to stand in the air.
We are reminded here of Duffy’s observations upon certain isomeric
transformations of the fats, (Quar. Jour. Ch. Sec. V. 197.) He
noticed that stearine heated 1° above its point of solidification,
became transparent, but soon after resumed its opacity; and Heintz
made a similar observation. Duffy attributes this to an isomeric
transformation of the fat by the heat; but it seems to me simpler until
an isomerism be more distinctly proven, to assume a mixture of fats,
which unite to form a definite compound under the circumstances, and
which has the above mentioned property.[7] Heintz’s researches on the
fats should make us look with suspicion upon fats as pure, that are
only purified by crystallization.
Duffy’s remarks were made upon the glycerine compounds of the
fatty acids; it appears from the above examination of the liquids
1^o and 6^o, as if something similar took place with the fatty
acids themselves, although, with one or two exceptions, in other
determinations of melting points noted in this article, I have not
observed the same phenomenon of transparency.
A few experiments were now made with the alcoholic liquid 6^o. A
concentrated alcoholic solution of acetate of magnesia added to this
liquid, produced no precipitate, but micaceous crystalline scales fell
on adding acetic acid, and upon adding more acetic acid, and heating,
besides these crystals, an oil floated on the surface, which solidified
on cooling, and which behaved like a fat, and gave the melting point of
palmitic acid, viz.: 62° (solidifies gradually from 47° to 39°.) The
crystals gave a small quantity of ash when burned on platina foil, and
on being decomposed by hydrochloric acid, gave a fat with the melting
point of stearic acid 72°-73°, and solidifying at 60°-55°. The mother
liquid contained too little fat to experiment upon. To another portion
of the liquid 6^o, alcoholic acetate of magnesia was added without
addition of acetic acid, and the solution evaporated in a retort. The
first crystals which appeared contained a fat which fused at 65°-68.5°,
and solidified at 62°-58°.
The solid crystalline fat No. 6 which was removed from the liquid 6^o,
and which was the most highly purified result from the crystallization
of this specimen of adipocire, was now examined more particularly;
an alcoholic solution was made upon which to try the different
experiments. Fifteen grammes of the fat required 300 of alcohol of
93 per cent. to keep it in solution; but before having added so
much alcohol, on standing for a short time 0.656 grammes of pearly
crystalline scales fell, which had a melting point of 62.5°, and
solidified at 55.5°. The fat of the liquid after these crystals had
fallen, when precipitated by water, melted at 58°-61°, and solidified
at 55.5°: these crystals, recrystallized from alcohol, melted at 62.5°,
and solidified at 58°-57°; these were dissolved a third time, in
twenty times their weight of 93 per cent. alcohol, which deposited, on
standing, less than a milligramme of tufted crystals of the form of
palmitic acid, of which it had the melting point 62°: more alcohol was
added to the solution, and it was divided by fractional precipitation
with acetate of magnesia and the addition of a little ammonia with
heat, into two portions, weighing 0.256 and 0.164 grammes, and they had
the same melting point. This fat appears, therefore, to be palmitic
acid, one of the acids into which Heintz divided margaric acid. The
crystals deposited from alcohol do not at all resemble those of
margaric acid, but under the microscope are lamellar. These two fats
were converted respectively, by an excess of nitrate of silver, into
silver salts, 0·24725 gave 0·074 Ag. = 29·93 per cent. and 0·14275 gave
0·04175 Ag. = 29·25 per cent., which corresponds to the percentage of
silver in the palmitate of this base.
C_{32} 192.00 By calculation. Mean of two Exper.
H_{31} 31.00
O_{4} 32.00
Ag. 107.97 29.7 29.5
——————
362.97
There is no doubt, therefore, of the presence of palmitic acid in the
fat of human adipocire. The second crop of crystals which fell from the
mother liquid of those just examined, contained a fat melting at 62°,
in all probability palmitic acid also. A determination of the silver
of the salt of this fat was lost in the following curious manner: The
silver salt was in lumps, as it had dried on the filter, and after
it had stood for a short time at 100 in a watch glass, thinking to
facilitate the escape of water, by pulverizing it in an agate-mortar,
it became so exceedingly electric, that of the whole quantity of silver
salt from 0.651 grammes of fat, I was not able to collect the smallest
portion for analysis; whether the powder was attempted to be removed by
steel, platinum, glass, a feather, or paper, on the first touch it flew
into the air, and alighted upon the table: I have often noticed this
behaviour in organic silver salts, and perhaps it would be worth while
to try whether one of them could not favourably replace the amalgam on
the cushion of the electrical machine.
The following experiments were made upon the alcoholic solution
of the fats, from which the above portions of palmitic acid were
separated. Enough alcohol was added to this solution to prevent any
further deposit by standing, for which, as was before stated, 300
alcohol were required for 15 fat. Its percentage of fat was determined
by evaporating the alcohol from a known quantity, and weighing the
residue; the melting point of this fat was 60.°5 to 61°. This melting
point was again determined after saponification, to ascertain whether
a fatty ether might not have been formed, and was found to be the
same. The alcoholic solution of acetate of magnesia was also titled
so that the necessary quantity might be added to the fat solution
by measurement: the fat under consideration should be, by Heintz’s
experiment, a mixture of stearic and the so called margaric acids,
together with impurities.
Before proceeding to the fractional precipitation by acetate of
magnesia, the alcoholic fatty solution was treated with an excess of
acetate of magnesia, and an excess of acetic acid (aided by a little
warmth) added; the resulting liquid was then evaporated over sulphuric
acid (removing the crystals as they formed) in order to ascertain what
effect this treatment would have upon the melting points. On cooling,
a small quantity of a powdery precipitate fell, and after standing
for a couple of hours over sulphuric acid, the liquid crystallized
rather suddenly, to plates or scales, the melting point of which, after
treatment with acid, gave 62°; recrystallized from hot alcohol it
melted at 62°5-63°.
[Transcribers note: Missing text.]precipitate the whole, was added; to the
filtrate an excess of the magnesia solution was added, and the fat
remaining in the filtrate from this precipitation was separated, as
was also that of the other two precipitates. The following results and
melting points are in their order as determined:
(_a_) 0·351 melts 61°
(_b_) 0·527 melts 61°
(_c_) 0·085 melts 53°
loss 0·173
—————
1.136 grammes.
(_a_) and (_b_) were united, dissolved in alcohol, enough alcoholic
solution of acetate of magnesia to precipitate the half added, and
after standing for a couple of days, the precipitate was filtered off,
and ammonia added to alkaline reaction to the filtrate. The first
magnesia salt was translucent, and fused by heat to a transparent
liquid, which by more heat gradually grew darker, finally black, and
left a residue of magnesia. The melting point of the fat of this
substance was as before, 61°.
The second magnesia salt was white and amorphous; it presented the same
relations to heat as the first, and contained a fat of the same melting
point, 61°. These fats were both brilliant white, lamellar, and of
rough surface. The first magnesia salt contained a per centage of 7·59
MgO (0·25025 gave 0·019) and the second contained about double the per
centage of magnesia, viz.: 14·91; for 0·28 salt gave 0·04175 magnesia
by incineration.
Neutral palmitate of magnesia C_{32}, H_{31}, O_{3} MgO gives by
calculation 7·6 per cent. magnesia, and basic palmitate C_{32}, H_{31},
O_{3} 2 MgO gives 14·15 magnesia, which approaches the nearest to the
magnesia salt of the above fatty acids.
The experiments of fractional precipitation of the normal solution
of fat 6°, were conducted in the same manner, and with the following
results, in which (_c_) and (_d_) represent the fatty acids of the two
magnesia salts, and (_e_) that of the portion not precipitated by an
excess of acetate of magnesia:
(_c_) 0·474 melt pt. 59.5°
(_d_) 0·440 melt pt. 61.5°
(_e_) 0·356 melt pt. 58.5°
loss during the ex. 0·010
—————
1·280 grammes of fat.
The magnesia salts from which the fats (_c_) and (_d_) were separated,
gave as follows:—(_c_) 0·227 gave 0·01675 = 7·38 per cent. magnesia;
and (_d_) 0·1735 gave 0·012 = 6·92 magnesia. On comparing the melting
points of these fats, and making allowance for want of a more perfect
separation from impurities, there can be little doubt that they are
neutral palmitates of magnesia, as was before ascertained. According
to Heintz (Zoochemie, p. 1072,) stearic acid is C_{36}, H_{36},
O_{4}, and the magnesia salt contains by calculation, 6·9 per cent.
of that base. The foregoing experiments upon the two specimens of
human adipocire were intended preliminary to a more thorough research
into their nature, by Heintz’s method; but this process requires such
a large quantity of substance in order to effect the separation of
small quantities of whatever new acid might be present, and the amount
of material dwindled so in the many necessary crystallizations from
alcohol to separate the dark-coloured impurities, and especially, since
the determinations and reactions already made, were so confirmatory
of what has lately been done in working upon the solid fatty acids,
I preferred placing aside the substances thus obtained for a future
examination, when the separation of fatty acids shall have become more
simplified, as it must be before long.
(_c_) _Fossil adipocire of Bison Americanus obtained from a metacarpal
bone from Big Bone Lick, by Dr. Leidy._--It was a white powder, and
in pulverizable lumps; amorphous under the microscope; with a talcose
feel, and of density a little below 0·8365, since it barely swims upon
alcohol of that strength, while it sinks in absolute alcohol. Water
will not wet it; with the addition of hydrochloric acid and heat, it is
separated without effervescence, into a mineral solution, and into an
oil which solidifies on cooling to a nearly white fat, a small portion
of which melted on a glass slide solidifies to a confusedly crystalline
mass; a small quantity treated in the same way with absolute alcohol,
crystallizes in plumose and dendritic crystals, like margaric acid.
A portion of the adipocire boiled with absolute alcohol, yields but
a minute quantity to the solvent, and that not of a fatty nature,
showing that the fatty acid is wholly saponified with an earthy base.
The whole quantity of adipocire weighed 0·986 grammes. 0·16325 heated
in a platinum crucible, fuses, burning with a smoky flame and with the
smell of fatty acid, but no acroleine, leaving 0·0165 or 10·1 per cent.
of a perfectly white ash, which hydrochloric acid almost perfectly
dissolves without effervescence, and which consists almost entirely of
lime, with a few minute specks of oxide of iron (seen during the action
of the hydrochloric acid,) and a couple of small grains of sand: there
is a very small trace of phosphoric acid present. The greater portion
of the adipocire, 0·716 grammes, was decomposed by hydrochloric acid
and water, by the aid of heat: the decomposition took place with a
strong smell of rancid tallow, and the fundamental smell observed in
all adipocire was emitted. It was melted and washed several times, at
first with acidulated and finally with pure water. The water from the
washing, when evaporated, gave a certain quantity of brownish yellow
colouring matter. The fat was melted in the capsule in which the
precipitation took place, and weighed 0·618 or 86·31 per cent. of the
adipocire; when melted, a dark flocculent humus-like precipitate was
seen; the fat itself was yellowish, and of a flat, waxy (here and there
warty) surface. It melted at 51°.
The adipocire therefore appears to be a lime soap of one of the fatty
acids, with a trace of phosphate of lime and with flocculent organic
matter, or in per centage approximately,
Fatty acids and a little colouring matter, 86·31
Lime and a trace of phosphate, 10·10
Flocculent organic matter, 3·59
——————
100.00
If the organic matter be neglected and the per centage then calculated,
we will have,
Fatty acids, 89·5
Lime, 10·5
—————
100·0
Now Stearate, Margarate and Palmitate of Lime, respectively contain
a per centage of 9·3-9·7——10·2, of lime, so it is reasonable to
suppose (as there is nothing in its reaction contrary, but everything
favourable to this supposition) that the fossil adipocire is a neutral
lime soap of the usual fatty acids of tallow.
_Experiments upon the decomposition of muscular fibre (bullock’s heart)
with water, with a view to the formation of adipocire._
A portion of raw, and one of boiled muscular fibre from bullock’s
heart, were on March 8th, 1854, placed with water upon a microscope
slide, and covered with thin glass, which was closed with sealing wax
around the edge to prevent evaporation. This was repeatedly observed
during the year, and the attention was directed at times to particular
fibres the better to watch any change. At the commencement of the
experiment, the cross-markings of the fibre were distinct and the fibre
itself was of a delicate rose-colour. I find in my notes of April 8th,
and May 11th, that no change presented itself in either the raw or in
the boiled fibre, except that the cross-markings were more distinct.
On December 6th, 1854, but very little change was noticed, (the raw
fibre was whiter,) the cross-markings in both were more distinct than
ever; by high powers an amorphous precipitate was discovered in the
neighbourhood of some of the fibres--about one third of the water had
evaporated.
_A._ On November 14th, 1853, 100 grammes of cheese were placed in a
loosely stoppered bottle, and covered with distilled water, a portion
of the same cheese being reserved for comparison: the water was renewed
as it evaporated.
_Ba._ On November 19th, 1853, one half of a bullock’s heart, weighing
673 grammes, was placed, covered with Schuylkill water, in a
wide-mouthed stoppered bottle.
_Bb._ The remaining half of the heart, weighing 816 grammes, was
covered with mineral water with lemon syrup. It was intended to use
plain mineral water in this experiment, that is, Schuylkill water
saturated with carbonic acid, but the former was sent by a mistake,
which was not discovered until too late. In these cases the fat was
partially removed from the heart, but not to any great extent.
_C._ Boiled six eggs, removed the shells from two, which weighed then
88 grammes; ran pin-holes to the centre in two, which weighed 97
grammes, and left the shells upon the remaining two, which weighed
96 grammes; these were together placed in a glass-stoppered bottle,
and covered with water. These different substances did not delay to
decompose and give out offensive odours, and the eggs especially
maintained their proverbial character in this respect; in fact, on the
approach of the cholera season I was obliged to place the bottle of
eggs on a plate, cover it with a large inverted beaker glass, and heap
the rim of the beaker with hypochlorite of lime. With regard to the
heart, the contents of the bottle containing mineral water, as might be
expected, preserved their lively red colour for a longer time than in
the case of the bottles containing river water.
The appearance of these bottles, on December 13th, 1854, was as
follows:—
The cheese _A_ was converted into a white, thick, grumous mass, lighter
than water, and which when diluted with a little water, presented the
appearance of pus; under the microscope with moderate power, angular
transparent fragments constituted the principal part, and among these,
polarized light showed many broken blade-shaped crystals without a
play of colours; a few globules of oil were also seen. The material
_A_ was removed to a glass-stoppered bottle, more water added, and was
set aside. A portion of the cheese used in this experiment had been
preserved in paper; it was found hard, and on the surface oily. It was
placed aside in a cork-stoppered bottle.
_B._ The bullock’s heart had been so divided, that each half contained
an auricle and ventricle, which were placed in the bottles, (_a_) with
water, (_b_) with carbonic acid water. The appearance of the contents
of these bottles at present is similar, though (_a_) seems to be more
disintegrated. In both of these, the cavities and valves of the heart
maintain, in a measure, their form, and the chordæ tendineæ are in
perfect preservation: the serous covering of the heart is consistent;
and in (_b_) it is, in parts, quite black from sulphuret of iron. The
fluid in both bottles reacts strongly alkaline; when the mass of the
heart is cut open, the muscular fibre appears of a dirty, yellowish-red
colour, and when examined under the microscope, shows the fibre, but
without any of the cross-markings in (_b_). In (_a_), which was more
disintegrated, by the addition of water and a power of 700 diameters,
the fibre could be seen broken in small portions, and giving evident
traces of both longitudinal and cross-breaking up of the sarcous
substance. The fibres of (_a_), treated with hot and cold alcohol
evinced no change; with hot acetic acid they shrunk in dimensions. The
weight of (_a_) dripping with liquid was 330 grammes, that of (_b_) 275
grammes.
_C._ The Eggs.--The water was strongly alkaline; the shelled eggs were
seen in broken, yellowish-white lumps, and a thick deposit at the
bottom of the bottle, gave no evidence of crystallization under the
microscope with polarized light. The liquid from the eggs and from the
two heart experiments emitted rather a disagreeable odour, which was
mingled with an aldehyde smell.
As decomposition had not advanced to its full extent in these bottles,
I preferred setting them aside for a future research, when both the
solid and the liquid contents will be examined. Braconnot’s[8] analysis
of bullock’s heart is as follows:—
Water, 77·03
Fibrine, cellular tissue, nerves, vessels, 17·18
Albumen and colouring matter of the blood, 2·70
Alcoholic extract and salts, 1·94
Aqueous extract and salts, 1·15
——————
100·00