All attempts to get the osdzone of the sugar ty the 



method of Fischer failed^ pr oh uuly on account of the small 



(luantity of the sugar present. The plant, it will he rememher- 



ed was originally extracted with ether in which rhamnose is 



practically insoluble. The above described testa, however, 



can leave no doubt as to the identity of the sugar. 



Additional evidence that the sugar is rhamnose was ob- 



2 

 tained by a method described by Maquenne as follows: 



"The production of methyl furfurol in the dehydration 

 of isodulcite furnishes a very simple means of charac- 

 terizing this sugar in mixtures which contain it; it is 

 sufficient, for example, to distil 50gm. of q.uercitron 

 wood with as much sulphuric acid and about 150gm. of 

 water, then to rectifj- the liquid obtained in order to 

 get several drops of the crude furfurol, which on addition 

 of alcohol and concentrated sulphuric acid gives immedi- 

 ately the green coloration characteristic of methyl 

 furfurol. This procedure is applicable to extracts 

 as well as to entire plants, and has the advantage that 

 it dibes not require the separation of isolulcite, the 

 cjrystallization of which is often very slow and at times 

 impossible when it is mixed with other very soluble 

 substances," 



The experiment was tried with the crude ether extract 



of the plant according to the directions of Maquenne, and the 



green color with alcohol and sulphuric acid was obtained from 



the thicker oily portion of the distillate. This test can 



3 

 be made with hydrochloric acid as well as with sulphuric. 



1. Berichte XX, pp. 1089 » 1091, 1188, 2566, 



2. Ann. de Chim. et de Phys. (6) XXII, 93 (1891), 



3. Biochem. der Pflan. I, 210. 



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