HANDBOOK FOR BIO-CHEMICAL LABORATORY. 45 



readily, which are soluble in water and most of them in alco- 

 hol. The zinc salt dissolves in 58 to 63 parts of water at 

 14-15 C. and contains 18.18$ water of crystallization, but is 

 insoluble in alcohol. The calcium salt dissolves in 9,5 parts 

 water and contains 29.22$ (= 5mol.) water of crystalliza- 

 tion, 



Sarcolactic Acid, 

 PARALACTIC ACID, C 3 H 6 3 orCH 3 .CH(OH).COOH, 



Preparation* Dissolve Liebig's extract of meat in 4 parts 

 of water and then add 8 parts 90$ alcohol, stirring all the 

 while, The mixture is allowed to stand and settle, and the 

 clear supernatant liquid is separated by decanfation. To re- 

 move any lactic acid from the insoluble residue, mix it with 

 twice its weight of warm water and precipitate by adding 4 or 5 

 times its volume of alcohol. The alcoholic solutions thus ob- 

 tained are evaporated on the water-bath to a thin syrup, and 

 this latter again precipitated by the addition of 3 or 4 times its 

 volume of alcohol. The alcoholic solution is now evaporated 

 to dryness, the residue mixed with water, some dilute H 3 S0 4 

 added, and then shaken several times with ether. On evapo- 

 rating the ethereal solution a residue is obtained which con- 

 sists of a mixture of sarcolactic and fermentation lactic 

 acids. 



To separate the two above acids they are dissolved in water 

 and boiled with zinc carbonate or zinc white, the solution 

 filtered, and the filtrate evaporated until crystals commence to 

 form. The liquid is now treated with 4 or 5 times its volume 

 of 90$ alcohol ; after some time the liquid becomes turbid 

 and deposits needles, consisting of zinc sarcolactate, the zinc 

 salt of the other acid remaining in solution. The crystals are 

 collected on a filter, washed with absolute alcohol, dissolved 

 in water, decomposed by H 2 S, filtered, concentrated, shaken 

 with ether, and the pure acid obtained on the evaporation of 

 the ethereal solution. 



