ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
559 
Function of Antitoxins.* — Dr. H. A. Cummins suggests tliat the 
principal purpose served by the formation of antitoxins (alkaloids and 
others) in plants is to protect them against the attacks of injurious bac- 
teria in the soil. This is confirmed by the fact that the production of 
poisonous principles varies in the same species with the nature of the 
soil. The antiseptic principles appear usually to be produced as the 
result of irritation of the cells by the entrance of organisms which cause 
fermentation of the juices of the plant, the antitoxin then killing the 
invading organism. 
Advances in the Chemistry of Fermentation.! — In an introduc- 
tory address, Prof. E. Buchner, after reviewing the history of the physio- 
logy of fermentation, alluded to Traube’s idea of the existence in yeast-cells 
of a body capable of exciting fermentation. The ill success of numerous 
experimenters in isolating this fermenting substance from the yeast-cells 
in the same way that invertin was isolated, resulted from the difficulty 
in crushing the thick cell-membrane in all the cells of a large quantity 
of yeast, and therefore of quickly emptying the cells of their contents. 
The author mixed the yeast with quartz sand. After long rubbing the 
mash becomes moist, and the fluid portion of the cell-contents escapes. 
Water is then added, and the whole mass exposed to a pressure of 500 
atmospheres. From the press runs out an almost clear yellow fluid, which 
amounts to nearly half of the whole of the cell- contents. In six hours 
500 cubic cm. of juice can be obtained from one kilogram of beer yeast. 
This juice possesses the property of fermenting carbohydrates without 
the presence of organisms. Mixed with one volume of strong saccharose 
solution, the development of C0 2 begins in a quarter of an hour, and in 
a refrigerator continues for more than 14 days. In this way alcohol is 
formed. Cane-, grape-, fruit-, and malt-sugars are fermentable just as 
well as with a living ferment, but not mannite or milk-sugar. The fer- 
ment, which is designated zymase, has the characters of albuminous bodies. 
It is not living protoplasm, as chloroform does not inhibit its action. 
Under natural circumstances it is apparently excreted by the yeast-cells, 
and becomes diffused in the fluid, and in this way effects the decompo- 
sition of sugar. Zymase is diffusible through parchment paper. By 
precipitation with alcohol it is rendered insoluble in water. When 
heated to 40°-50° there is a copious deposit of albumen, and the filtrate 
has no fermenting power. The ferment is so inconstant that after 
standing for five days in the refrigerator in half full flasks, its efficiency 
disappears. Hence the author thinks that zymase is more closely allied 
to the living protoplasm of the yeast-cells than to invertin, and belongs 
to the genuine or native proteids. 
Butylalcohol Fermentation.^ — Induced by Fitz’s works, Herr 0. 
Emmerling sought in cow-dung and in hay for the ferment which decom- 
poses glycerin in butylalcohol ic fermentation. After frequent failure 
he finally succeeded in obtaining this fermentation from hay grown in 
Alsace. The Butyl-bacillus thus found is identical with that described 
by Fitz, but not with the Granulobacter saccharobutyricus of Beyerinck. 
* Proc. Asiatic Soc. Bengal, 1897, pp. 15-21. 
f Tubingen, 1897, 23 pp. See Bot. Centralbl., lxxi. (1897) p. 38. Cf. this 
Journal, ante, p. 414. 
‘ J Ber. Deutsch. Chem. Geselh, 1897, No. 4. See Centralbl. f. Bakt. u. Par., 
2 te Abt., iii. (1897) p. 322. 
