78 Production of Acetylmethylcarbinol and 2.3-Butylene Glycol. 



glucose. It would be interesting to find whether the same relationship holds 

 in the case of glycerol and glyceraldehyde. Formic acid (or its decomposi- 

 tion products, C0 2 and H 2 ) and alcohol, which might be formed according to 

 the equation 



C 3 H 8 3 = C 2 H 6 + CH 2 O a> 

 make up 64 — 77 per cent, of the glycerol fermented. 



Summary. 



1. The volatile reducing substance obtained by Pere in the aerobic 

 fermentation of mannitol by B. subtilis and B. mesentericus vulgatus, and of 

 glucose and glycerol by Tyrothrix tenuis, is acetylmethylcarbinol, which is 

 readily volatile in steam, gives the Voges and Proskauer reaction, and forms 

 the phenylosazone of diacetyl. 



2. The action of B. lactis aerogenes on glycerol, under anaerobic conditions, 

 does not give rise to any reducing substance. 



The products of this decomposition have been quantitatively estimated and 

 are as follows : — Ethyl alcohol, formic, acetic, lactic and succinic acids, carbon 

 dioxide, hydrogen and 2.3-butylene glycol. 



[Note added February 29, 1912. — Since writing the foregoing paper our 

 attention has been called to a paper by Fernbach* in which he shows that 

 T. tenuis acts both on glucose and glycerol with the production of non- 

 volatile dihydroxyacetone. Volatile reducing substances were also formed 

 which he regards as a mixture of methylglyoxal and formaldehyde. Since 

 neither of these substances is optically active they cannot be identical with 

 the lsevo-rotatory substance obtained by Pere and ourselves, so that Fern- 

 bach's observations in no way disprove our conclusion that the optically 

 .active, volatile substance produced is acetylmethylcarbinol.] 



REFERENCES. 



(1) Pere, ' Ann. Inst. Past.,' 1896, vol. 10, p. 417. 



(2) Wohl, 'Ber.,' 1898, vol. 31, p. 1800. 



(3) Harden and Norris, ' Roy. Soc. Proc.,' 1912, B, vol. 84, p. 492. 



(4) Harden, ' Boy. Soc. Proc.,' 1906, B, vol. 77, p. 424. 



(5) Grimbert, ' Conipt. Bend.,' 1901, vol. 132, p. 706. 



(6) Walpole, 'Boy. Soc. Proc.,' 1911, B, vol. 83, p. 272. 



(7) Desmots, 'Compt. Rend.,' 1904, vol. 138, p. 581. 



(8) Harden, ' Chem. Soc. Journ.,' 1901, p. 610. 



(9) Harden, Thompson, and Young, 'Biochem. Journ.,' 1910, vol. 5, p. 230. 



(10) Zeisel and Fanto, ' Z. anal. Chem.,' 1903, vol. 42, p. 551. 



(11) Fletcher and Hopkins, 'Journ. Phys.,' 1907, vol. 35, p. 247. 



* ' Compt. Bend.,' 1910, vol. 151, p. 1004. 



