ENZYMES. 41 



Other cleavage processes are certain so-called fermentation processes, 

 which are connected with the presence of living organisms, fungi and 

 bacteria of various kinds. Among these we include chiefly the alcoholic 

 fermentation and butyric acid fermentation of carbohydrates. Accord- 

 ing to the view based upon PASTEUR'S investigations it has been gen- 

 erally considered that these processes are phases of the life of these 

 organisms and the name organized ferments or ferments have been given 

 to such organisms, especially to the ordinary yeast fungus. 



A ferment, according to this view, is a living organism. By the name 

 enzyme, as introduced by KUHNE, we mean a product of the chemical 

 processes in the cells, which is active without the life of the cell and which 

 can be separated from the cell. The decomposition of invert sugar into 

 carbon dioxide and alcohol in fermentation is considered as a fermentative 

 process closely connected with the life of the yeast fungus. The inver- 

 sion of cane-sugar previous to fermentation is on the contrary, an enzymotlc 

 process which is brought about by a body or mixture of bodies which 

 are formed in the fungus and which can be removed from the fungus 

 and are still active after the death of the fungus. Consequently fer- 

 ments and enzymes are capable of manifesting a different behavior toward 

 certain chemical reagents. Thus there exist a number of substances, 

 among which we may mention arsenious acid, phenol, toluene, salicylic 

 acid, boracic acid, sodium fluoride, chloroform, ether, and protoplasmic 

 poisons, which in certain concentration kill ferments, or at least retard 

 their action, but which do not noticeably impair the action of the enzymes. 



The above view as to the difference between ferments and enzymes 

 has lately been essentially shaken by the researches of E. BUCHNER : 

 and his pupils. He has been able to obtain from beer-yeast, by grind- 

 ing and strong pressure, a cell-fluid rich in protein, and which when intro- 

 duced into a solution of a fermentable sugar caused a violent fermenta- 

 tion. The objections raised from several sides that the fluid expressed 

 still contained dissolved living cell substance has been so successfully 

 answered by BUCHNER and his collaborators that there is at present 

 no question that alcoholic fermentation is caused by a special enzyme or 

 mixture of enzymes called zymase, which is formed in the yeast-cell. 



As from the yeast-cells so also from other lower organisms, indeed 



1 E. Buchner, Ber. d. deutsch. chem. Gesellsch., 30 and 31; E. Buchner and Rapp, 

 ibid., 31, 32, 34; H. Buchner, Stizungsber. d. Gesellsch. f. Morphol. u. Physiol. in 

 Miinchen, 13 (1897), part 1, which also contains the discussion on this topic. See also 

 E. and H. Buchner and M. Hahn, Die Zymasegarung, Munchen (1903); Stavenhagen, 

 Ber. d. deutsch. chem. Gesellsch., 30; Albert and Buchner, ibid., 33; Buchner, ibid., 

 33; Albert, ibid., 33; Albert, Buchner, and Rapp, ibid., 35; in regard to the opposed 

 views see Macfadyen, Morris, and Rowland, ibid., 33; Wroblewski, Centralbl. f . Physiol., 

 13, and Journ. f. prakt. Chem. (N. F.), 64. 



