BY R. GUEIG SMITH. 121 



The purified siilt from Bad. nietarabiauin ^vas found to be 

 dextro-rotatory, indicating that the acid contained laevolactic 

 acid. The zinc salt of the acid produced by Bact. acacice was 

 prepared and re-crystallised. It contained 13-1 % of water of 

 crystallisation driven off at 140° C. As optically inactive lactate 

 of zinc contains 3 molecules of water of crystallisation, equal to 

 18-18 %, and the active salt 2 molecules, equal to 12-9 %; it is 

 evident that the acid consists chiefly of an active acid. The 

 specific rotation of the hyd rated zinc salt was found to be [a^] =- 

 + 5-58°, and of the acid to be [au] = -3-69*^. According to 

 Schardinger the si3ecific rotation of laevolactic acid is — 43^, and 

 according to Purdie the pure hydrated zinc salt of laevolactic 

 acid has a rotation [00]= +6-81'. The lactic acid formed by 

 Bact. acacice therefore consists chiefly of laevolactic acid, and this 

 undoul)tedly also holds for Bact. metarahimmi. 



The mother liquor from the calcium lactate was evaporated 

 almost to dryness and treated with strong alcohol. Crystals 

 separated from the alcohol. These gave no odour of acetic acid 

 on treatment with sulphuric acid. The analysis showed the 

 following figures : — 



0-0912 grm. gave 0-0542 grm. CaCO. = 23-78 % Ca. 

 Calcium aspartate contains ... ... 23-13 % Ca. 



The precipitate was probably the calcium salt of aspartic acid, 

 doubtless derived from the residual asparagine upon boiling the 

 culture medium with barium hydroxide. 



The method which was employed in the separation of the non- 

 volatile acids is practically that of Schoorl; in the preliminary 

 experiments it had been found to be most satisfactory. Malic 

 acid could not be detected in the cultures. 



The acids in the culture of Bacf. metarabluum were identical 

 with those obtained from Bad. acacice, with one exception. In 

 place of lauric acid a mixture of a solid acid and another, fluid 

 at the laboratory temperature, was obtained. This was peculiar 

 because in the preliminary test the insoluble fatty acid was lauric 

 and identical with that yielded by BacL acacioi. The (quantity 

 was, however, too small to separate the constituents. 



