THE EXTRACTIVES OF MUSCLE, 



107 



Calcium sarcolactate, Ca(C 3 H 5 3 ) 2 + 4 or 4J H 2 0. Soluble in 12*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 



1 



(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 raceinic 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 

 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 

 ylaucum, to grow in a solution of 

 the inactive compound ; one only 



FIG. 18. Zinc sarcolactate. After Klihue. 



|f jt 

 | * 



Hi 



V! 



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 FIG. 19. Calcium sarcolactate. After Kiihne. 



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 Schardinger, Monatsh. f. Chem., Wien, Bd. xi. 



2 Blaclistein, Arch, de sc. lioL, St. Petersbourg, tome i. p. 199. 



3 Ann. de. chim., Paris, Ser. 2, tome xxiv. p. 442 ; xxviii. p. 56 ; Compt. rend. Acad. 

 d. sc., Paris, tome xxxvi. p. 26; xxxvii. p. 162; Ann. d. Phys. u. Chem., Leipzig, Bd. 

 Ixxx. S. 127 ; xc. S. 498, 504. 



4 Purdie and Walker, Trans. Chem. Soc. London, 1892, p. 754 ; 1893, p. 1143. 



