/ 2 The Fermentation of Cacao 



to set in again from the surface downwards. 

 All these results will probably lead to the 

 acknowledgment that an oxydase assists in 

 producing the brown colouration of the beans, 

 and that this is brought about by the oxidation 

 of the tanriic substances. Whether a decom- 

 position of the glucosides takes place prior 

 to oxidation has still to be investigated and 

 ascertained. The behaviour of beans with a 

 whitish break, i.e., Criollo beans, differs from 

 the beans having purple cotyledons, i.e., of the 

 Forastero variety, inasmuch as the devitalizing 

 temperature is 5 to 10 higher (for Criollo 

 beans), but in other respects the conditions 

 are the same. Here, again, we have the same 

 tannic substances formed in the white cells, 

 as can be proved if sections of the beans are 

 examined. Under the microscope the cells 

 containing the tannic substances can be 

 distinguished in the purple (Forastero) beans, 

 on account of the purple-coloured matter 

 they contain, which matter also is of a tannic 

 character. 



Comparing the results of all these experi- 

 ments led to the discovery that the oxida- 

 tion of tannic substances increases very quickly 

 in weak alkaline and neutral reaction, and that, 

 on the other hand, with an increased propor- 

 tion of acid, the influence of the oxydase 

 diminishes to a corresponding degree. The 

 concentration of the acid which is noticeable 

 in the pulp (some tfe to i normal) causes, 



