TUCCA ANGUSTIFOIilA. 270 



Gum. 



One volume of the aqiceoics extract was mixed with two voUimes of stronger 

 alcohol. The precipitate was collected after twenty-four hours, washed with 66 per 

 cent, alcohol, dried, and weighed. The precipitate and filter were incinerated, and the 

 ash estimated. 



Weight of precipitate by stronger alcohol yielded 0.775 per cent 



ash yielded 0.125 



CarhJiydrates. 



The gum fdtrate and wash alcohol were concentrated at a low tempe'rature, and 

 the residual liquid mixed with four volumes of stronger alcohol. The resulting precipi- 

 tate was rapidly filtered and collected. The percentage of carlliydrates was estimated 

 gravimetrically from a copper solution in the usual way. It amounted to 0.525 per 



cent. 



Carhhydrate Filtrate. 



The fiUrafe was evaporated to dryness. A part of the residue was boiled with 83 

 per cent, alcohol. On cooling, a iirecijjitate formed. It was identified by the usual tests 

 as saponin. Another portion of the residue was precipitated with ])asic acetate of lead. 

 The lead precipitate was decomposed by sulphuretted hydrogen, the solution fil- 

 tered, and the filtrate evaporated over a water bath until all odor of sulphuretted 

 hydrogen was dissipated. A part of the lead sulphide filtrate was mixed with lime- 

 water, and a precipitate fornied not completely dissolved by acetic acid. The remain- 

 der of the lead sulphide filtrate was allowed to evaporate over sulphuric acid. The resi- 

 due consisted of a mass of fine crystals radiating from a centre.* 



The crystals gave a very acid reaction when placed on moistened blue litmus 

 paper. They turned black and left a residue when heated on |il,ilimim foil, and the 

 residue was sloAvly dissolved by nitric or hydrochloric aciil. Tlic quantity of residue 

 was very small, and no effervescence was observed. The melting point of the crystals 

 was taken. A small quantity Avas placed in a tube Avith thin walls, and gradually 

 heated ; at 150° C. the substance sublimed, leaving a Avhite, cloudy stain on the inner 

 surfiice of the tube; at 190° C, this cloudy stain changed to a pale green spot, and 

 with increasing temperature to 210° C, no further change was noted. Dry sodium 

 carbonate was added to an aqueous solution of the crystals, and a slight effi-rvesccncc 

 Avas observed. Some iron A\-as scparate<l Avhich possibly Avas in combiiKiiion with the 



• The material nsed in this analysis of the green part of the leaf was quite dry and powdered readily. A previous 

 examination of the/r«*A Uaten gave more satisfactory quantitative resulLs. A gum was extracted which promises to ho 

 of interest for a future study, and the crystals separated from the lead sulphide filtrate arc to be further investigated. 



