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indiean-solution, there is at least required of the different crude 
enzymes 2 milligrams of Indigofera, 20 of Polygonum and Saccharo- 
myces sphaericus, and 60 of emulsine. 
COU NGL U SAB NS. 
The splitting of the indican by the cell can occur in two ways: 
by ferment-action of the living protoplasm itself (katabolism), and 
by enzymes. 
All examined bacteria, which act on indican, split by katabolism 
and hence are in dead condition inactive. The most important among 
them are the common ferment-bacteria (Aérobacter) of sugar-containing 
plant infusions. 
All indican-plants and some species of alcohol-ferments contain 
indigo-enzymes and consequently can decompose the indican in dead 
condition too. Indigo-enzymes originate only at abundant access of 
air. Five of these enzymes proved specifically different, with tem- 
perature optima of 61° (Zndigofera), 55° (emulsine), 53° (Phajus), 
44° (Saccharomyces sphaericus) and 42° (Polygonum). For all of them 
the action is favoured by free acid to an amount of 0.5 cc. normal 
per 100 ce. of the employed indican-solution; more acid, like alkali, 
opposes the action. 
Indigofera decomposes the indican only by enzyme-action; in the 
case of Polygonum tinctorium and Phajus grandiflorus the indican 
is decomposed partly by katabolism, partly by enzyme-action. 
In the leaves of Phajus grandiflorus indican is localized in the 
colourless protoplasm of mesophyll and epidermis, the indigo-enzyme 
exclusively in the chlorophyll-granules. 
Chemistry. — “Indican — its hydrolysis and the enzyme causing 
the same.” By J.J. HazewinxeEL, Director of the experimental 
station for Indigo at Klaten (Java). (Communicated by Prof. 
S. HOOGEWERFF). 
The following investigations were done by me in November 1898. 
After the investigation was closed, I received by the mail the trea- 
tise of MARCHLEWsKI and I then went to Buitenzorg to consult 
Dr. van Rompureu about these researches. 
I first thought it would be better, in the interest of the Javanese 
indigo growers to keep the results of my work a secret, but having 
been informed by Prof. BEIJERINCK that he also had taken up the 
