524 
SECOND REPORT—1832. 
chemistry has received of late years are contained in the valu¬ 
able work of Tiedemann and Gmelin on the phenomena of di¬ 
gestion*. They examined with much minuteness the various 
fluids concerned in the process of digestion; and in particular 
they investigated very closely the constitution of the bile, and 
found in it many substances not previously detected. According 
to them, the bile of the ox contains 9T5 per cent, of water, and 
the remainder consists of a volatile substance having the smell 
of musk, cholesterine, resin, bile asparagine, a crystalline sub¬ 
stance they have since named taurine , picromel, colouring- 
matter, a substance resembling gluten, caseous matter, ptya- 
line, or salivary matter, albumen, mucus from the gall-bladder, 
osmazome, an extractive matter insoluble in alcohol, together 
with bicarbonates, acetates, oleates, margarates, cliolates, sul¬ 
phates and phosphates of potash and soda, common salt, phos¬ 
phate of lime, and a little carbonate of ammonia. 
MM. Tiedemann and Gmelin consider all these substances to 
exist ready formed in the bile ; Berzelius f, however, whose ex¬ 
tended researches in animal chemistry are well known, thinks 
it more likely that some of them are formed by the action of the 
various reagents employed in extracting them from the bile. 
Urea. —A very interesting discovery lately made by Wohler, 
is the artificial formation of urea. If cyanate of silver be treated 
with a solution of sal ammoniac, or cyanate of lead with caustic 
ammonia, a substance is obtained in transparent, colourless, rect¬ 
angular four-sided crystals, which contains the elements of cy¬ 
anic acid and ammonia, but which contains no ammonia, and 
possesses all the properties of urea. Wohler has since suc¬ 
ceeded in forming a cyanate of ammonia possessing the charac¬ 
ters of a salt. The following formulas show the identity of 
composition of urea and cyanate of ammonia with one atom 
water. 
Urea. Cyanate of ammonia. 
2C+2N+4H+20... = (N + 2C) + 0 + (N + 3 H) + (H + O) 
Uric acid. —-Uric acid, according to Dr. Prout, consists of 
6 C + 2 H + 3 0 + 2 N. Kodweiss J has lately analysed it under 
the direction of Liebig, and obtained carbon 39*79, hydrogen 2, 
nitrogen 37*4, oxygen 20*81 = 10 C-f3 H + 4 O +4N. The 
atomic weight =5*298. 
Cyanurate of urea. —He has also found that the sublimate 
obtained by the dry distillation of uric acid, which was shown 
by Wohler to consist of cyanuric acid and urea, is not a mixture 
but a compound of these two substances, which may also be ob- 
* Die Verdauung nack Versuchen: Heidelberg, 1826. 
O 
+ Arsberattelse, 1827, p. 311, | Pogg. xix. p. 1. 
