CHAPTER XXVII 



THE MICROBE OF VINEGAR 



THIS microbe is represented in Fig. 62. In form 

 it is cylindrical, and it appears in single cells, fila- 

 ments and chaplets. The longer diameter is from 

 one and a half to three micromillimeters ; its 

 shorter diameter is about one half this length. 

 This means that many hundred millions of these 

 beings could find plenty of room in a small drop 

 of water. But they cannot live in water. They 

 are aerobic, that is, air-breathing; and can live 

 only in the air. 



All the genuine vinegar in the world is made 

 through the agency of this microbe. Spurious 

 vinegar may be made of chemicals; the genuine 

 only by this living being. The true process con- 

 sists in converting the alcohol of some liquid into 

 acetic acid. Any one of many kinds of liquor may 

 be used for this purpose. The essential requisite 

 is that the liquor used shall, by having been 

 made by the fermentation of certain materials, 

 contain from four to ten per cent, of alcohol. 

 Cider is the best. It contains about eight per cent, 

 of alcohol. By one set of microbes the apple juice 

 is converted into cider; by another set the cider 

 is converted into vinegar. 



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