ANIMAL OIL OF DIPPEL. 
245 
preparation employed byM. Dippel and the older physicians. 
He has found that Dippel obtained this oil by distilling animal 
oil without addition, until a black residuum no longer remained, 
so that he submitted it to five distillations at least. This 
process was successively modified in some points by Frederic 
Hoffman and George Model. Still later, it has been directed 
to agitate the black oil of hartshorn with warm water to separate 
the supernatant oil from the aqueous solution which contains 
the major part of the ammoniacal salts contained in the oil, 
and to distil this until it commences to pass over of a yellow 
colour; and finally to distil it alone until it leaves no more 
residue. The author repeated the process of Dippel upon a 
volatile animal oil which had already a clear yellow colour. 
Successive distillations were practised in a retort, by means 
of a salt water bath; the black residue diminished gradually, 
and it was only after being repeated four times that it disap- 
peared entirely. The product of the fourth rectification was 
then as clear as water, its refrigerant power was considerable, 
it had the agreeable smell of cinnamon, and a burning taste — 
afterwards sweet, which recalled that of good cinnamon and 
pepper; yet if preserved any length of time, even in a dark 
place, it recommenced to become yellow. The specific 
gravity of this oil was = 0.S65. Rubbed with caustic potassa, 
it gave rise to the disengagement of ammonia when aided by 
heat. 
The result of this experiment accords with the last re- 
searches of M. Reichenbach, upon the products of dry 
distillation of organic bodies. This skilful chemist has 
demonstrated, in fact, that all sorts of pitch, and consequently 
the oil of hartshorn also, afibrd eupione, creosote, capnomore, 
picamare, ammonia, acetic acid, &c. But by the successive rec- 
tifications of animal oil, the greater part of the substances 
little volatile, such as creosote, picamare, capnomore, as well 
as the peculiar principle easily oxydized, remain by little and 
little in the retort, whilst in the product of the distillation, 
eupione ought to be found in combination with a certain 
quantity of picamare and of capnomore, of which it is difficult 
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