50 Kansas Academy of Science. 



gators into organic and inorganic. The organic ferments are 

 those catalytic agents produced in living cells or tissues or 

 produced by the processes of nutrition of low organisms, 

 which have the property of accelerating the decomposition of 

 complex unstable compounds into simpler substances. The 

 inorganic ferments are those catalytic agents of the mineral 

 world composed of colloidal solutions of the nobler metals, as 

 platinum, silver, iridium, gold, which have the property of 

 accelerating the chemical reactions of two different substances. 

 Here also we deal with chemical reactions which take place 

 even when no ferments are present. Thus far no objection 

 can be safely and permanently maintained against this clas- 

 sification, but to divide the former class, namely, the organic 

 ferments, into two classes or groups, the so-called organized 

 and unorganized, cannot be successfully accomplished. The 

 term organized ferments is applied to those which are con- 

 nected in some way with the life of the cells in which they 

 are produced and which cannot be extracted from these cells.. 

 The unorganized ferments, commonly called enzymes, can, 

 on the other hand, be extracted from the cells in which they 

 are formed, and are able to produce their characteristic ac- 

 tions outside of the cells as well. Those who hold to this 

 classification of organized and unorganized organic ferments, 

 the enzymes, admit that the list of the unorganized ferments 

 is constantly growing at the expense of the organized; that 

 as soon as we will be able to successfully extract the organ- 

 ized from the living cell we will speak of unorganized fer- 

 ments or enzymes alone. Buchner's successful extraction of 

 zymase from the yeast-cell, which is able to bring about the 

 decomposition of glucose into alcohol and carbon dioxid quite 

 as readily as the yeast-cell itself, is a grand demonstration of 

 the certainty of the coming of such events. Ferments play 

 a most important part in the phenomena of assimilation and 

 of disassimilation of foods. Most of the foods which occur 

 in nature at the disposition of men, lower animals or plants, 

 are not directly assimilable; they require the intervention of 

 a ferment in order to be transformed into substances as- 

 similable and suitable for the formation of new tissues. Pep- 

 sin is one of the oldest, if not the oldest, and most thoroughly 

 well known ferment. It was so named by Schwann in 1835, 

 fifty-six years after Spallanzani had shown that the gastric 

 juice can produce chemical changes outside of the body. This 



