280 A CHEMICAL, STUDY OF 



ciystallinc principle. jSTegative results followed tests for formates, acetates, malates, 

 tarti-ates, citrates, phosphates, oxalates, alkaloids, and glucosides. 



The amount of glucose present in the aqueous extract was too small to determine 

 quantitatively. iN^egative results for tannin. 



Extract (4), the Yellow Base of the Leaf. 



The residual powder from the alcoholic maceration was dried and replaced in the 

 ]iercolator. Cold distilled water was allowed to percolate slowly through the powder. 

 The aqueous extract was slightly acid in reaction. A known measure of it was evapo- 

 rated, dried, and weighed. The ash was determined from a part of the aqueous extract 

 residue. 



TOTAL SOLIDS. 



Aqueous residue dried between 100° aud 110"^ C 11.35 per cent. 



ash 3.10 



Oum. 



One volume of the aqueous extract was mixed with two volumes of stronger 

 alcohol. The precipitate was collected, washed with 66 per cent, alcohol, dried, and 

 weighed. The ash was calculated from incinerating the precipitate, and deducting the 

 filter. 



Weight of precipitate by stronger alcohol j'ielded 3.850 per cent. 



ash yielded 0.G76 



Carhhydrates. 



The filtrate and wash alcohol from the gum precipitate were concentrated at a Ioav 

 temperature. The residual liquid was mixed with four volumes of stronger alcohol, when 

 a precipitate formed, and was rapidly filtered off. The carNiydrates were dissolved in 

 water, hoiled with dilute acid, and the liquid rendered alkaline and heated over a Avater 

 l)ath with Fehling's solution. The amount of carhhydrates was estimated gravimetric- 

 ally in the usual way. It gave 2.95 per cent. 



CarhJiydrate Filtrate. 



The filtrate residue was examined for glucose, and traces of it were present. The 

 filtrate residue was precipitated with acetate of lead, and the lead precipitate was dis- 

 solvofl in watci- and decomposed by sulphuretted hydrogen. The lead sulphide fil- 

 trate was tested qualitatively for organic acids, and a turbidity formed on adding to the 

 filtrate lime-water. It was not completely cleared by acetic acid. 



Negative results followed tests with alcoholic methyl-violet solution for mineral 

 acids. The aqueous extract contained no tamiin. Calcium oxalate was determined in it. 



