ON THE HORNS OF OXEN. 
528 
of magnesium, chloride of sodium, phosphate of lime, oxide 
of iron, and silicic acid. The analysis gave the following re- 
sults : — 
Carbon 50.46 50.83 — 
Hydrogen 6.65 6.68 — 
Nitrogen — — 16.23 
Oxygen and sulphur 26.66 26.26 — 
Diluted sulphuric acid and horn . — Twelve parts of water 
and four parts of sulphuric acid were boiled with one part of 
horn filings for three days. The sulphuric acid was saturated 
by excess of milk of lime, the liquid boiled again for twenty- 
four hours with the precipitate, the latter pressed, the liquid 
neutralized by sulphuric acid, then filtered, and a solution of sugar 
of lead added, till every excess of sulphuric acid was removed. 
The excess of lead was removed by sulphuretted hydrogen, the 
liquid boiled with the precipitated suphuret of lead, and a 
slightly coloured liquid filtered from it, which, on being evapo- 
rated, yielded crystals. These were washed, then boiled in 
water with a small quantity of potash and carbonate of potash, 
and the carbonate of lime having been filtered off, the liquid 
was saturated with acetic acid, and the solution allowed to be- 
come cold. The crystals of tyrosin were purified by solution in 
water and spontaneous evaporation, by the aid of charcoal. 
When air-dry they form a coherent mass with a silk-like lustre, 
consisting of long conglomerated needles, which are themselves 
composed of small needles grouped in the form of stars. They 
burn on platina foil without leaving a residue, but emitting a 
smell of burnt hair ; they are soluble in ether or absolute alcohol, 
with great difficulty only in cold water, rather readily in boiling 
water, and very readily in alkalies and mineral acids. From a 
solution in ammonia, they reappear, upon the spontaneous eva- 
poration of the latter unaltered, but in a larger form. The 
crystals of tyrosin from horn possess the same properties as the 
tyrosin obtained by Liebig from casein, and by Bopp from 
fibrin and albumen ; they were dried at 100° and analyzed, and 
the results agree perfectly with those obtained by Warren de la 
Rue in the analysis of the tyrosin from cochineal and lead, con- 
quently also to the formula C 18 Hn N0 6 . 
Carbon 59.36 18 = 108 59.67 
Hydrogen 6.34 11 — 11 6.08 
Nitrogen .. , 7.88 1 rz 14 7.73 
Oxygen 26.52 6 ” 48 26.52 
100.00 181 100.00 
The leucin was discovered in the mother liquor of the tyrosin, 
when the above described operation was so far altered, that the 
sulphuric liquid, after having been saturated with excess of 
