The Last Word 263 



Carbonic acid, 4*5 per cent. 



Oxygen, 12 '8 per cent. 



Nitrogen, 827 per cent. 



A simple calculation shows that for every 

 two unit-volumes of oxygen used up, one unit- 

 volume of carbonic acid has been formed, 

 Experiments conducted on parallel lines led 

 to the same results. One may probably 

 gather from this that oxidation is associated 

 with a breaking up and giving off of carbon 

 dioxide (Koklenstoffabspaltung}. 



Whether the oxidation is preceded by a 

 splitting off of glucosides has not been definitely 

 determined. Lazarus certainly affirms that a 

 glucoside (cacaonine) occurs in fresh beans, 

 being composed of sugar, cacao -red and 

 the alkaloids caffeine and theobromine. 1 

 Schweitzer 2 has confirmed this, and also iso- 

 lated an enzyme capable of splitting glucoside. 

 These experiments require repeating and 

 checking, however. 



The behaviour of the beans having white 

 nibs differs from that of those with bluish-red 

 cotyledons, in that the devitalizing temperature 

 of the oxidase stands at about 5 to 10 C. 

 higher. In other respects the conditions are 

 the same. The tannin-containing cells of the 

 white beans are just as much developed, as 

 may be shown by treating sections with tannin 



1 Review, Botanisches Centralblatt, 1893, Bd. Ivi, 

 p. 296. 



2 Pharmaceutisch Zeitung, 1898, Bd. xliii, p. 381. 



