(: 3108) 
The solution of the enzyme in salt was prepared by shaking 1 
part of the prepared leaf-powder with 20 parts of a 10 per cent 
solution of salt, for 20 minutes. 
There remains, therefore, no doubt that the action deseribed is 
due to an enzyme and such a one whose action is analogous or 
identical with that of emulsin. | 
The substance which is decomposed under the influence of the 
enzyme must, therefore, be a glucoside. Then: 
1. It is decomposed (hydrolysed) by enzymes. 
2. One of those enzymes is emulsin which, as is perfectly well 
known, is an enzyme capable of decomposing glucosides. 
3. This hydrolysis is accompanied by a large increase in copper- 
reducing power. 
4. By the action of acids, dextrose is formed. ') 
Although the said glucoside possesses properties which differ from 
those usually ascribed in the literature to indican, I think it is as 
well to retain that name for the glucoside. 
Although I had no time to attempt the isolation of indican, some 
of its properties may be described here. 
1. Acid oxidating agents convert it into indigo which, in turn, 
is oxidized by an excess of the reagent. 
2. It is soluble in alcohol but not in ether and cannot be removed 
by means of ether from neutral or acid solutions. 
3. It may be preserved for an indefinite period if kept sterilized. 
4. It is stable at the boiling heat. 
5. It is very stable in the presence of strong alkaline solutions 
at not too high a temperature. 
6. With concentrated acids it forms red products, particularly 
on warming, if excess of acid be avoided. A knowledge of these 
products will be of the greatest importance for the study of the so- 
called indigo-red which occurs in samples of natural indigo. 
7. An excess of ferric chloride gradually decomposes indican 
completely, without formation of indigo. 
8. Indican reduces an ammoniacal solution of silver nitrate in 
the cold with separation of metallic silver. 
The first property suggests many means of determining the yield 
of indigo from a given solution of indican. 
My first decisive experiment was made by oxidizing equal parts 
of indican solution with different quantities of an oxidizer (5 KBr + 
1) VAN LOOKEREN CAMPAGNE, Landwirtschaftliche Versuchstationen, Bnd. 45 pg. 195 an, 
