RESEARCHES IN ANIMAL CHEMISTRY. 
149 
XLTX RESEARCHES IN ANIMAL CHEMISTRY. 
By Prof. J. Liebig. 
I have latterly made a series of researches on the nature 
of fluids, which belong neither to the sanguineous nor lym- 
phatic vessels. The Academy will permit me to draw its 
attention to the results I have obtained. We know long 
since that the meat of animals recently killed presents a re- 
action decidedly acid. M. Berzelius has attributed this 
property to the existence of lactic acid, without, even to the 
present moment, analytical results having proved the fact 
in an irresistible manner. Many chemists have admitted 
the existence of lactic acid in the urine, in the gastric juice, 
and in the milk, but they supported the conclusion of its 
existence in those liquids, on reactions which do not possess 
great certitude. Even the opinion that lactic acid hinders 
the precipitation of oxide" of copper by the milk of lime, rests 
on an error. M. Strecker has lately shown that the lactate 
of pure copper is perfectly decomposed by the milk of lime, 
and in the supernatant liquid, no reaction demonstrates the 
presence of oxide of copper. It is true that the lactate of 
pure lime dissolves a trace of oxide of copper; but a slight 
excess of lime water precipitates it entirely. 
My researches have aimed at putting an end to this in- 
certitude in respect to the non-volatile organic acid, which 
constitutes a part of the animal organism. 
When the flesh of animals recently killed and beaten into 
a pulp is washed with cold water, a red liquor is obtained? 
which, heated to ebullition, gives a coagnlum of albumen, 
and is almost entirely deprived of colour. The limpid liquid, 
scarcely yellowish, obtained in this manner, possesses a very 
decided acidity and a very aromatic and agreeable flavor of 
boiled beef. When neutralised by barytes water, there is 
precipitated phosphate of barytes and phosphate of mag- 
