174 MODERN SCIENCE READER 



from 1896, appeared in the year 1903. It is entitled "Die 

 Zymasegdrung: Untersuchungen uber den Inhalt der Hefe- 

 zellen und die biologische Siete des Garungsproblems." The 

 authors' names are Eduard Buchner, Hans Buchner, and 

 Martin Hahn ; and it became evident something noteworthy 

 had happened. It was briefly this: Buchner, unhampered 

 by any prejudice concerning the connection of vitality with 

 fermentation, betook him to see what was really inside the 

 yeast cell. Accordingly, he mixed a small quantity of 

 barm with very fine sand, and he then subjected the whole 

 to enormous pressure. This hard quartz crushed the little 

 yeast cells to merest pulp, and therefrom flowed a wonder- 

 working fluid. It was found that Buchner 's liquor effected 

 exactly the same fermentation in a saccharine solution as 

 did yeast itself. This research of Buchner 's actually 

 proved what was long ago conjectured by Liebig, Traube, 

 Berthelot, and Hoppe-Seyler, namely, that the intra-molec- 

 ular transformation of sugar into alcohol and carbon 

 dioxide is due to an enzyme secreted within the yeast cell. 

 This capital demonstration forms a fitting climax to a 

 long series of speculations on collateral fermentations. We 

 will call to mind the main results achieved by toilers in 

 these different fields of research. In the year 1841 two 

 French chemists, Payen and Persoz, succeeded in isolating 

 from germinating barley a substance which seemed to 

 possess an unlimited capacity for saccharifying starch. 

 They called this substance diastase. Later on, in 1860, we 

 find Berthelot experimenting with yeast, and he isolated 

 the substance to which Bechamp, in 1864, gave the name 

 zymase. Thirty years after Donath changed this name to 

 invertin, and we thus clearly have species of chemical sub- 

 stances which, when abstracted from living organisms, are 

 able to effect certain well-defined fermentations. Mean- 

 while, it has been shown that many processes of higher life 

 appear to be governed by these soluble, unorganized fer- 

 ments, or, as Kuhne, in 1878, proposed to call them, 

 enzymes. Incidentally, I should here mention that, like 



