M. Lautemann on the Preparation of Lactic Acid. 385 
while the ammonia is liberated as gas. The mixture is then 
filtered, saturated with sulphuretted hydrogen, filtered and 
evaporated ; on cooling, alanine is obtained in beautiful crystals. 
6 yT4 2 16 Fy4 2\—2 
On Giys }O?+2NHP+2HO=" saiaatis J-O?+ CHO? NECA 
sip : bide Alcohol. Chloride a. 
Chloropropionic ; Amidopropionie aiionine 
ether. acid. 
According to Lautemann*, the following is an advantageous 
modification of Bensch’s method of preparing lactic acid. The 
proportions of sugar, tartaric acid, milk, and cheese are the same ; 
but instead of chalk an equivalent quantity of oxide of zinc (com- 
mercial zinc-white) is employed. The temperature must be 
between 40—50°; the fermentation is complete in eight or ten 
days. The whole mixture is boiled in a copper vessel, filtered, 
evaporated, again filtered, and allowed to stand. On cooling, pure 
lactate of zinc separates. To obtain the free acid the lactate 
is dissolved in boiling water, the zine separated by sulphuretted 
hydrogen, filtered and concentrated. This solution contains man- 
nite and lactic acid; to separate the two it is agitated with ether, 
which dissolves the lactic acid, and leaves the mannite. On eva- 
porating the etherial solution the lactic acid is left behind. 
Kekulé found} that chloracetate of potass, when heated in 
the presence of water, is decomposed with the assimilation of 
two equivalents of water, forming chloride of potassium and 
glycolic acid :— 
C*H? C1 K 0*4+2HO=KCl1+C* H‘ 0°. 
Chloracetate of Glycolic 
potass. acid, 
Heinz has foundt{ that when the same salt is heated in 
methylic alcohol, or, still better, when free chJoracetic acid is 
treated with methylate of soda, chloride of sodium and a new 
acid are formed :— , 
C* H® Cl 04+ C? H3 NaO?= NaCl + C* H® 08, 
Chloracetic Methylate New acid. 
acid. of soda. 
This experiment was undertaken in the expectation of forming 
lactic acid. The new acid is, however, isomeric, and not iden- 
tical with lactic acid. The reaction is capable of great extension ; 
by acting on the homologues of methylic alcohol, a series of new 
acids is obtained corresponding to the higher members of the 
lactic acid series. 
* Liebig’s Annalen, February 1860. 
+ Phil. Mag. vol. xvi. p. 138, 
} Poggendorff’s Annalen, Feb. 1 860. 
