THE EXTRACTIVES OF MUSCLE. 
107 
Calcium sarcolactate, Ca(C 3 H 5 3 ) 2 + 4 or 4£ H 2 0. Soluble in 1 2 -4 parts 
of cold water and in all proportions of boiling water or alcohol. 
These salts are levorotatory, though the free acid is dextrorotatory. 
This is produced by the fermentation 
FlG. 18. — Zinc sarcolactate. — After Kuhne. 
(c) Levorotatory lactic acid 
of cane-sugar by means of a 
special kind of bacillus, 1 and 
is also found in cultures of 
Gaffky's typhoid bacillus in 
a solution of sugar and pep- 
tone. 2 Very little is known 
about it yet. 
In all cases where three 
isomerides exist, as in the 
present case — one optically 
inactive, one levorotatory, 
and the third dextroro- 
tatory — it should be under- 
stood that strictly speaking 
there are only two isomer- 
ides, one dextro- the other 
levorotatory, the third or 
inactive variety being a com- 
pound of the other two. 
This was first shown by 
Pasteur 3 in connection with racemic acid, which is optically inactive. 
By appropriate methods of crystallisation it can be separated into two 
varieties of tartaric acid, one dextrorotatory, the other levorotatory. 
Another method of separating 
an optically inactive material into 1 
its optically active components, 
has been alluded to on p. 32, in 
connection with glutaminic acid 
and leucine. It consists in allow- 
ing moulds, like Penicillium 
glaucum, to grow in a solution of 
the inactive compound: one only 
of its active components is des- 
troyed by the mould, and the 
other remains untouched. In the 
case of optically inactive lactic 
acid, the question has been 
attacked by the method of 
crystallisation of various of its 
compounds, particularly of those 
with strychnine, and also of zinc ammonium lactate. 4 
The mode of formation of lactic acid in muscles has been the subject 
of numerous researches. That the acid is sarcolactic acid has been 
1 Seliardinger, Monatsh. f. Ohem., "Wien, Bd. xi. 
- Blachstein, Arch,, de sc. biol., St. Petersbourg, tome i. p. 199. 
"Ana. de. chim., Paris, Ser. 2, tome xxiv. p. 442; xxviii. p. 56 : Oompt. n ml. Acad, 
d. sc, Paris, tome xxxvi. p. 26: xxxvii. p. 162; Ann. d. Phrjs. u. Chem., Leipzig, Ed. 
lxxx. S. 127 ; xc. S. 49S, £04. 
4 Purdie and Walker, Trans. Chan. Soc. London, 1892, p. 754 ; 1893, p. 1143. 
Calcium sarcolactate. — After Kiilme. 
