214 MR. E. SCHUNCK ON THE 



mixed with about twice its volume of ether, which imme- 

 diately turned it milky and produced a deposit consisting of 

 a brown syrup. This syrup was allowed to settle and the 

 whole was left to stand for twenty-four hours. The surface 

 of the syrup and the sides of the glass vessel were then found 

 to be covered with a quantity of small, almost white crystals. 

 These crystals are the same as those referred to above as 

 being obtained in the preparation of indican, when ether is 

 added to the alcoholic solution of the latter. I was at first 

 inclined to suppose that they consisted of a substance which 

 was contained as such in the plant, but I soon discovered 

 that they were a product of decomposition of indican, as they 

 were also obtained from perfectly pure indican, which had 

 been prepared by successive solution in alcohol, water and 

 ether, in the last of which the crystals are insoluble. Indeed 

 no product of decomposition of indican seems to be so easily 

 formed as this. By shaking the liquid from which they 

 were deposited the crystals were easily detached from the 

 sides of the vessel and the surface of the syrup. They 

 were collected on a filter, washed with ether, and then 

 pressed between folds of blotting-paper in order to absorb 

 any of the syrup which might be mixed with them. They 

 were then dissolved in boiling water, and the solution 

 having been decolorised with animal charcoal was filtered 

 and evaporated, when it left a crystalline mass, which was 

 again pressed between blotting-paper and dissolved in a 

 small quantity of boiling alcohol. The alcoholic solution 

 on cooling deposited a mass of small crystals, which had the 

 properties and composition of 



Leucine. 



It crystallised from the alcoholic solution in small flat tables 

 having a pearly lustre, which repelled cold water like a fatty 

 acid but were readily soluble in boiling water. It was insoluble 



