October 21,1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
323 
being thus treated in a manner specified, it may be 
used for all culinary preparations, and even for 
pastry. For this fact he furnishes the following 
scientific explanation. 
M. Dubrunfaut has practically ascertained, by 
laboratory and manufacturing experiments, that 
fish oil is radically deprived of its odorous principle 
by simply heating it to a high temperature (330° C.). 
He has also found that the fatty acids are volatilized 
in a current of steam at a temperature above 100° C., 
whilst the neutral fats remain perfectly fixed. Fi¬ 
nally, he has found that the neutral fats comport 
themselves in a similar manner to the fatty acids 
under the influence of a current of steam, if they 
have previously been heated to a temperature of 
Lorn 300° to 330° C. 
The manner in which the purification is effected 
is by heating the fat in a frying-pan or other suit¬ 
able utensil to a temperature of about 140° to 150° C., 
then cautiously sprinkling upon it small quantities 
of water. The vapour so caused traverses the fat, 
decomposes the neutral fatty substances,—which, as 
shown by M. Clievreul in the case of hircine, yield 
fatty acids,—the whole of the fatty acids are volati¬ 
lized, and the purification is accomplished. These 
conditions, he says, unite all the elements which are 
favourable to the elimination of the volatile fatty 
acids, which are generally the material cause of the 
odours of fat substances. The product thus ob¬ 
tained is as perfectly purified as the finest lard. 
M. Dubrunfaut had so much faith in the efficacy 
of this method of purification, that he called atten¬ 
tion to the large quantity of candle tallow still in the 
city, and stated that by a modification of the process 
to suit the known constituents of the tallow, the 
whole of it might be so purified as to fit it for use in 
cooking various kinds of coarse flours, such as buck¬ 
wheat flour, and thus secured for the purposes of 
alimentation. The same method might also, he 
stated, be applied to the large stock of colza oil. 
In a second note presented to the Academy* M. 
Dubrunfaut again called attention to the facility 
with which the large stocks of tallow and colza oil 
might be utilized for food, while the mineral oils 
would suffice for the purposes of lighting. On this 
occasion he pointed out the similarity of the origin of 
the kitchen fats and the tallow of commerce, and 
said that the absence from the kitchen fats of the 
repulsive odour of the tallow was due to the method 
of preparation. In the operation of roasting meat 
especially the conditions necessary for the purifica¬ 
tion of the fat—the high temperature and the super¬ 
heated vapour—were realized in perfection. And 
although they were present in a less degree in the 
operation of boiling, still there was a real purifica¬ 
tion. This opinion is supported by the fact that 
tainted fat, undergoing ebullition in a melting-pot 
in the presence of salt water, is purified in propor¬ 
tion as the boiling is prolonged. 
As the result of various experiments in which 
colza oil was treated according to M. Dubrunfaut’s 
method, he reported that the oil lost its characteristic 
taste and odour, preserving only a slight savour that 
was not repulsive, and would not prevent its use in 
culinary operations. 
MM. Wurtz and Willm reported! that they had 
found that when colza oil was submitted to a current 
of steam at a temperature of from 116° to 120° C., an 
odorous and acrid principle was carried off without 
sensibly saponifying the oil,—an inconvenience 
which followed the employment of steam too highly 
heated. Washing with a feeble warm solution of 
carbonate of soda takes away all traces of the fatty 
acids that may have been formed, or have pre-existed, 
in oil of bad quality; but the separation of the soap 
so formed presents some difficulties.* 
M. Fua suggested! a modification of M. Dubrun¬ 
faut’s method, which consisted in melting the fats at 
so high a temperature that the residue of the cel¬ 
lular and vascular tissues were thoroughly exhausted. 
He also expressed an opinion that these methods for 
the purification of fats were preferable to the intro¬ 
duction of either acids, alkalies, or other substances, 
as these foreign bodies had always to be removed 
afterwards. 
DIGITALIS. X 
BY J. MILNER EOTHERGILL, M.D. 
The following particulars as to the composition, che¬ 
mical characteristics, action, etc. of digitalis, are taken 
from the essay on “ Digitalis : its Mode of Action and its 
Use,” by Dr. J. Milner Fothergill, Senior Resident 
Medical Officer to the Public Dispensary, Leeds, for 
which that gentleman received the Hastings medal at 
the recent meeting of the British Medical Association at 
Plymouth. 
Composition .—The leaves of digitalis have been sub¬ 
jected to repeated chemical examination, chiefly by 
foreign investigators. It has been found that there are 
various substances, which can be separated from one an¬ 
other, contained in them. The principal of these is 
digitaline. Indeed, by some it is considered the active 
principle; but of this Dr. Fothergill is not convinced; 
certainly it did not act on frogs so powerfully as the 
tincture of the leaves did. It is, however, frequently 
used. Digitaline is light yellow, inodorous, and crystal¬ 
lizes with difficulty, presenting the appearance of very 
imperfect crystals, if crystals at all, under a pretty high 
magnifying power (x 250). It does not contain nitro¬ 
gen, nor does it neutralize acids. It is a principle, not 
an alkaloid. It is soluble in sulphuric acid, and also in 
hydrochloric acid. The solution in hydrochloric acid 
passes from yellow to a fine green. Homolle considered 
this reaction sufficiently delicate for medico-legal pur¬ 
poses. It is scarcely necessary to state that it is not 
generally accepted as being so. There are also digitalic 
acid, digitalin, digitalose, digitalide, of whose qualities 
we know nothing. There are also tannic acid, sugar, 
and a substance named pectin, chlorophyll and woody 
fibre. 
Chemical Characteristics .—A dark precipitate (tanno- 
gallate of iron, —Pereira) is formed on the addition of 
sesquichloride of iron to the decoction, or to a mixture 
of the tincture and water. A solution of gelatine causes 
a scanty precipitate (tannate of gelatine). Tincture of 
* Somo idea of the importance of this subject to the Pari¬ 
sians under then existing circumstances may be inferred from 
the fact that the stock of colza oil in the reservoirs at Saint- 
Ouen and La Valette was estimated at from 12,000,000 to 
13,000,000 kilograms. This enormous quantity had been ac¬ 
cumulated by speculators who, anticipating a great demand 
for illuminating purposes, had obtained the oil from all the 
markets of Europe. It was the ordinary colza oil of com¬ 
merce, prepared by warmth from the seeds of Brassiest Jfaptis, 
and had not undergone sulphuric purification which, while 
rendering: it combustible, would have unfitted it for alimen- 
tation. 
t Comptes Rendus, lxxii. 59. no -n 
J Abstracted from tbe Hastings Prize Essay, for 18<0, 
published in the British Medical Journal, Nos. 548 to 553. 
* Comptes Rendus, lxxii. 57. 
f Ibid, lxxii. 57. 
