ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 501 



charbon disease, all the animals took this, viz. Chabert's disease, and 

 six of the number died, while the four which were the first to receive 

 the injection survived, owing to the liquid at the top of the vessel 

 used containing fewer bacteria than that at the bottom, which was 

 used for the last six animals ; the traces of the inoculation left upon 

 the surviving four similarly depended in their importance on whether 

 the animal was injected first, second, third, or fourth ; thus the fourth 

 had an abscess which had not closed at the time of writing. In fine 

 this and a following experiment show that — 1. Chabert's disease is 

 distinct from bacteridian charbon. 2. The virus of the latter does 

 not vaccinate against the former. 3. Algerian sheep are just as 

 subject to Chabert's disease as the French breed. 4. The amount 

 of virus employed has an important bearing on the results. 5. How- 

 ever slight the effects of the first inoculation may be, they confer 

 immunity from the disease. 



Manufacture of Vinegar by means of Bacteria.* — According 

 to Pasteur, the formation of vinegar from alcohol is due to the 

 vegetation of Mycoderma aceti. Liebig, however, maintained that it 

 is due to chemical and not physiological action, since no Mycoderma 

 aceti could be detected by microscopical examination on a shaving 

 from the bottom of a vinegar generator which had been in use for 

 twenty-five years. Mayer and De Knierym, however, distinctly 

 proved that the ferment exists in great quantity on the shavings of 

 the vinegar generator. 



E, Wurm has carried out the manufacture accordiug to the 

 directions of Pasteur (sowing the Mycoderma by a wooden spatula), and 

 most satisfactory results have been obtained. When the vinegar has 

 reached the required strength, it is drawn off into vats, where it is 

 clarified and freed from Mycoderma. The precautions to be observed 

 are — the sowing of pure bacteria, a uniform temj)erature of 30*^, and a 

 well regulated addition of alcohol. The chief advantages of this 

 process are its cheapness and the great economy of space, and a much 

 greater yield. 



The generation of " vinegar eels " is of great inconvenience, since 

 by their motion they destroy the pellicle of the Mycoderma and 

 prevent its reforming. If they multiply to any great extent, the 

 temperature of the liquid falls, but by preventing the cooling, the 

 parts of the pellicle destroyed may be reproduced, in which case the 

 eels take refuge in the upper parts of the vessel, and form a ring of 

 viscosity above the layer of bacteria. In this process, however, they 

 have not time to multiply so as to become injurious, since the vats 

 are emptied every ten to fourteen days. The Mycoderma used for 

 sowing must not come from a liquid infected with eels. 



The microscopical examination of the ferment shows that three 

 different forms can be observed. Whether they are from the same 

 organism in different stages of development, or three dilferent organ- 

 isms capable of producing acetic acid, remains to be proved. 



* Pharm. Journ. (Trans.) xi. (ISSl) pp. 132-4. See Joum. Chem. Soc. 

 (Abstr.) xl. (1881) pp. 128-9. 



