THE EXCREMENTS OF MAN AND ANIMALS. 
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the smell peculiar to fresh evacuations. With the view of obtaining it pure, I first 
dissolve it in ether, in order to remove a solid granular substance of a light consist- 
ence, insoluble in ether and in cold, alcohol, but dissolving readily in hot, and 
forming a solution which yields, when concentrated, a number of round globules. 
These when heated upon the platina knife, fuse, and then burn, evolving a smell of 
burnt meat, and leaving behind a residue difficult to incinerate; but not having 
succeeded in obtaining this substance in a crystallized state, I cannot say more at 
present as to its properties. The oil deprived of the above granular substance, and 
dissolved in ether, was mixed with alcohol, and subsequently lime-water was added ; 
the mixture was then heated upon the water-bath, until a heavy precipitate, consisting 
of a compound of this oil with lime, had been deposited. This precipitate was 
collected upon a filter, thoroughly washed with hot and cold alcohol, and the filtrate 
set aside. The insoluble salt of lime obtained was now decomposed with sulphuric 
acid, and treated with ether, in order to separate its organic constituent. The 
ethereal solution was then well washed with water, to get rid of the sulphuric acid 
it contained, and when evaporated down on the water-bath, yielded a pure fatty 
substance having a constant fusing-point. This substance, dried over sulphuric acid 
at the temperature of the atmosphere, is solid, but fuses invariably between 25° and 
26° Centigrade, showing it to exist in a pure state. When heated on a platina 
spatula, it first fuses, evolving a smell somewhat resembling that of excretine ; it 
next takes fire and burns with a bright flame, which disappears as soon as the 
platina foil is removed from the lamp; a black stain remains, which, by further 
application of heat, is completely removed. When boiled with a solution of caustic 
potash, the substance does not dissolve, but floats on the surface of the liquid. It 
is insoluble in water, but very soluble in ether, sparingly so in cold alcohol, but 
dissolving readily in hot, and not precipitating on cooling. Its solution possesses a 
marked acid reaction. 
It is not easy to determine whether this chemical compound, which I propose to 
name Excretoleic acid , is, or is not an immediate principle of human faeces. I am 
inclined to believe that it exists in them as an acid salt, the base being excretine, or 
a substance whose properties exactly resemble those of excretine, except that it fuses 
apparently at a lower temperature. This base is obtained in the filtrate from the 
precipitate which occurred when milk of lime was used to purify excretoleic acid. 
I have several times found the filtrate, after twenty-four hours, full of a crystalline 
mass, which, viewed under the microscope, resembled excretine, possessing the same 
properties of solubility in alcohol, ether, &c., but fusing at a lower temperature, 
between 70° and 80°, very probably because I had not obtained it in a perfectly 
pure state. When this substance was not found crystallized in the alcoholic filtrate, 
it was obtained by evaporating the solution to dryness and taking up the residue 
with ether, when it crystallized by spontaneous evaporation. 
We have already seen that the addition of milk of lime to the clear cold alcoholic 
2 n 2 
