FERMENTS AND ENZYMES. 9 



which are products of the chemical work within the cell, and which after 

 they are removed from the cell still have their characteristic action. 

 Such bodies for example, malt diastase, rennin, and the digestive fer- 

 ments are capable in the very smallest quantity of causing a decom- 

 position or cleavage in very considerable quantities of other substances, 

 without entering into permanent chemical combination with the decom- 

 posed body or with any of the cleavage or decomposition products. These 

 formless or unorganized ferments are generally called enzymes, according 

 to KUHXE. 



A ferment in a more restricted sense is therefore a living being, 

 while an enzyme is a product of chemical processes in the cell, a product 

 which has an individuality even without the cell, and which may be 

 active when separated from the cell. The splitting of invert-sugar into 

 carbon dioxide and alcohol by fermentation is a fermentative process 

 closely connected with the life of the yeast. The inversion of cane- 

 sugar is, on the contrary, an enzymotic process caused by one of the bodies 

 or a mixture of bodies formed by the living ferment, which can be separated 

 from this ferment, and still remain active even after the death of the latter. 

 Consequently ferments and enzymes are capable of manifesting a differ- 

 ent 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, 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 1 

 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 

 Munchen, 13, 1807, part 1, which also contains the discussion on this topic. See also 

 E. and H. Buchner and M. Hahn, Die Zymasegarung, Miinchen, 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. 



