Dr. A, Schulte im Hofe 77 



thought the German word "Gang" would be better, 

 i.e., " Passage," but here again there probably is 

 some technical term, and I believe "tunnel" is 

 best.] 



WHEN I was in British India some seven- 

 teen years ago, I turned my attention to the 

 study of indigo fermentation, believing that 

 the experience I had gained in the sphere of 

 industrially applied fermentation would prove 

 of .particular value to me. From all that I 

 had read and heard about the manufacture of 

 indigo, I had come to the conclusion that 

 micro-organisms played an important role in 

 the production of indigo from Indigofera 

 tinctoria, but I was very soon able to prove, 

 however, that the process known as " ferment- 

 ation " in the manufacture of indigo has 

 nothing to do with the formation of com- 

 mercial indigo, and that, in fact, the latter 

 can be obtained from the plants even 

 when the fermentation process is entirely 

 omitted, because, as a matter of fact, the 

 formation of indigo depends on a process of 

 oxidation. 1 



When, some years later, I took up the study 



1 Dr. A. Schulte im Hofe: " Indigokultur und 

 Fabrikationin Britisch Indien," Der Tropenpflanzer, 1902, 

 pp. 70 to 128. " Studien uber den Gehalt der Indigofera 

 tinctona au Indican, sowie liber die Gewirmung des 

 Indigo." " Berichte der Deutschen Pharmazeutischen 

 Gesellschaft," 1902, p. 19. 



