184 ANNUAL KECORD OF SCIENCE AND INDUSTRY. 



atmospheric pressure, while the vapor tension of the solid ni- 

 trous oxide is less than one atmosphere, 1 A, February 28, 

 1873, 103. 



ACTION OF SILICATE OF SODA OX FERMENTATION. 



According to MM. Rabuteau and Papillon, silicate of soda 

 has a very decided chemical action in checking alcoholic fer- 

 mentation, in this respect being somewhat similar to borax, 

 although much more energetic. A small quantity of the sil- 

 icate will entirely arrest the fermentation of wine, as also of 

 milk. 3 B, October 10, 1872, 222. 



CONTROVERSY BETWEEN PASTEUR AND FREMY. 



M. Fremy, the well-known opponent of the theoretical views 

 of Pasteur in regard to fermentation, etc., claims to have pro- 

 duced alcoholic, lactic, and butyric fermentation, and to have 

 caused fermentation in the heart of organic cells, in the ab- 

 sence and without the possible access of atmospheric germs. 

 He also claims to be able to show that alcoholic, lactic, and 

 butyric fermentation are not derived from germs, and trans- 

 formed one into the other, or produced with the same organ- 

 isms and the same fermentable liquors. 



Pasteur promptly responds to this, by saying that the germ 

 of the yeast from grapes is the Mycoderma mni ; that grape 

 yeast differs from beer yeast, properly so called, in the fact 

 that it has not a single cell of the beer yeast; that grape 

 yeast is identical with beer yeast of low fermentation ; and 

 that the Mycoderma vini is one of the germs most common 

 in the air, particularly in the summer; although it appears 

 to have two modes of life. In mother liquors, it seizes the 

 oxygen of the air, and makes it serve for its nutrition, and 

 delivers it in the state of carbonic acid ; in ferments, it de- 

 velops itself free from air, and becomes alcoholic and grape 

 yeast. 3 A, October 5, 1872, 281. 



ALCOHOLIC FERMENTATION. 



Schnetzler informs us that alcoholic fermentation, with 

 the evolution of gas, is caused by living cells of the fungus 

 known as Saccharomyces, present in the ferment, and that 

 there are cases in which other species of fungi, as Mucor, As- 

 2:>ergiUus, and PefiiciUiiim, present in the same liquid, produce 



