274 
DR. MARCET ON THE IMMEDIATE PRINCIPLES OF 
plex nature. If the above alcoholic extract after having stood for twenty-four hours 
be decanted, and the precipitate collected at the bottom of the beaker thrown upon a 
filter, the deposit presents an olive-brown appearance, a strongly acid reaction, and 
the foetid smell peculiar to faeces. When viewed under the microscope, it appears to 
consist principally of small oily globules, of a yellow-green colour, having a strong 
refracting power, and mixed sometimes with crystals of excretine accompanied by a 
yellow amorphous deposit. This deposit invariably occurred in every healthy human 
evacuation that I examined. After a few hours, it had assumed a gelatinous con- 
sistence ; if it was then boiled with alcohol in a capsule or a glass flask as long as 
it yielded anything to that fluid, and finally filtered through white calico, a substance 
was left behind, insoluble in boiling alcohol. This substance, when heated upon a 
platina knife, first fuses, then burns with a flame evolving an oily smell, and leaves a 
residue of white ashes. The alcoholic filtrate from the above substance, after having- 
been allowed to stand for twenty-four hours, yielded a deposit which fell to the 
bottom of the beaker; the whole vvas next thrown upon a filter, thoroughly washed 
with cold alcohol, and the washings together with the filtrate concentrated on the 
water-bath. The solid substance remaining on the filter was then washed with 
ether and yielded an ethereal solution of a yellow colour and very acid. The residue 
was of a light yellow colour, and, when viewed under the microscope, appeared to 
consist of an amorphous mass free from globules ; dried on filtering-paper, it became 
nearly colourless and of a light friable nature. When heated on a platina knife, it 
first fused and assumed a dark colour, emitting a smell of burning oil ; it afterwards 
burnt with a bright fuliginous flame, and finally left a residue of porous white ashes, 
consisting of phosphate of potash. It did not dissolve in boiling water, but fused 
and floated on the surface ; it was also insoluble in cold alcohol, and when suspended 
in that liquid sunk very slowly to the bottom, appearing to have nearly the same 
specific gravity. It is soluble in boiling alcohol, and on cooling is again preci- 
pitated. It is very sparingly soluble in cold ether, but becomes more so when heat 
is applied. 
I have not yet sufficiently examined the properties of this substance to be able to 
determine whether it is a pure immediate principle; indeed, from my having failed 
in my endeavours to obtain it crystallized, it might be regarded as a mixture of 
several principles. The above-mentioned properties, however, are distinctly defined, 
and under all these circumstances, I am inclined to consider it as a combination of 
phosphate of potash and a purely organic substance. 
The ethereal extract obtained from the above substance deposits by spontaneous 
evaporation a crystalline matter, which has not yet been obtained in sufficient quan- 
tity to admit of its being examined. 
The clear cold alcoholic solution obtained from the olive-coloured acid deposit, or 
the filtrate from the substance just described, having been evaporated down on the 
water-bath, yielded a deep olive-coloured oil, quite fluid when warm, and emitting 
