=... , 
ME forBenis on Urines Saft 
oz. df. gr. 
Muriatic falts 2 6 digworic= aii OreMic 
Phofphoric falts - =. 3 §° 
Lithicvacid and phofphat of lime; with excefs of 
acid 2 2 whnis +le70ngO! 25 
Animal extractive matter = 4; (3: 40 
The neutral falts, when purified by cryftallifation, are ge- 
nerally very fufible; but this circumftance varies much, 
according to the greater or lefs proportion of phofphoric falts, 
more particularly the phofphat of ammonia, on which their 
fufibility in a great meafure depends: inftead of inelting, this 
faline matter fometimes decrepitates when fuddenly heated, 
owing to an excefs of the muriatic falts: of thefe laft it may 
be obferved, that the muriat of potafh isin general the moft 
prevalent, and is eafily diftinguifhed from the muriat of foda, 
by its cryftallifing in fome degree by cooling, and by its 
affording cream of tartar on the addition of acid of tartar. 
In recent urine the ammonial falts bear a.very {mall pro- 
portion ; but when it has become ftale or putrid, they are 
much more abundant. The phofphat of ammonia is the 
principal, although we have likewife met with the muriat 
of ammonia. 
(A.) The lithic acid and phofphat of lime are generally 
depofited, at leaftin a great meafure, after the urine has be- 
come cold and ftood for fome time : the quantity of the firft 
varies exceedingly, but that of the laft we have found, for 
the moft part, nearly the fame, the proportion being about 
1 grain to 2ounces. Thefe fubftances may be eafily diftin- 
guifhed, by diffolving them in twice their weight of nitrous 
acid, diluted with a little water, and evaporating to drynefs ; 
the dry mafs when hot will affume a beautiful deep rofe or 
crimfon colour, when the lithic acid is prefent, but will 
continue white if heated even to rednefs, or have only a 
flight greenifh tinge when there is nothing but phofphat of 
lime. Their relative proportions may be afcertained by ex- 
pofing the mixed mafs for fome time to a red heat in a cru- 
Vou. II, R cible ; 
