44% Experiments on Urine. 
eible; in which cafe, the lithic acid. will either burn out or 
evaporate, leaving the phofphat 1 in.a pure fiate. 
The quantity of extractive matter is more variable thar 
that of any other fubftance—hyfterical or crude urine (as it’ 
has been called) containing hardly any, while that of con- 
coction abounds with it. This matter yields, by diftillation, 
water containing the carbonat of ammonia; this earbonat 
in a concrete flate; a foetid empyreumatic oil; a little phof- 
phorus; and laftly, a refiduum of animal coal difficult to 
incinerate: in fhort, nothing more than the ufual produéts 
from animal fubftances. If tox oz. of this extract be added 
1 oz. of the concentrated nitrous acid, diluted with an equal 
quantity of water, a violent effervefcence, accompanied with 
heat and the difengagement of nitrous gas, will take place : 
when the aétion has ceafed, and the liquor become cold, a 
number of fhining {eales, or cryftals, refembling the acid of 
borax, will be depofited, which, when well dried on blotting- 
paper, will be round to weigh from 5 to 7 dr. or fometimes 
more, the proportion varying according to the quality of 
the extract and the method of conduéting the procefs. The 
figure of thefe feales appears to be that of flat rhomboids ; 
they have a fmooth greafy feel when preffed between the 
fingers; are foluble in-much greater quantity in hot than 
cold water, and alfo in fome degree in alcohol : although re- 
peatedly wafhed with this fluid, and dried on blotting-paper, 
they itill retain acid properties, and firongly redden the fyrup 
of violets; they are readily taken up by the fulphuric and 
muriatic acids without commotion; but with the nitrous 
acid they produce a kind of effervefcence, and form very fo- 
Jnuble neutral falts, whofe properties have not been fufficiently 
examined. Their folution in water does not precipitate lime- 
water, nor the muriats of lime or barytes, nor the nitrats of 
filver or mercury, in any fenfible degree, nor has it any effeét 
‘ upon the fulphat of iron or acetite of lead; they do not, 
therefore, contain phofphoric or oxalic acid: when thrown 
upon a red hot iron, they melt and evaporate in white 
fmoke, 
