OF THE TAGUA NUT 543 



that a little fixed oil was obtained by the agency of solvents. Distilled with 

 water, no trace of any volatile oil was noticed. Heated with hot water, or allowed 

 to stand some time in contact with cold water, some soluble matter was taken up 

 which was obtained again by evaporation. Rubbed in a mortar with water, a 

 milky liquid was obtained, which gave only slight traces of coagulable matter by 

 boiling ; and yielded a soluble precipitate when heated with acetic acid. Both 

 alcohol and ether, when boiled on the powder, took up a very little matter. 

 Caustic potash ley, when boiled on it, became yellowish in colour, and when 

 supersaturated with muriatic acid, precipitation ensued. Muriatic acid, boiled on 

 the powder, also acquired a yellow tint. 



Having, in preliminary trials, satisfied myself as to the general nature of the 

 constituents, the following method of analysis was adopted : 



A portion of the powder was rubbed dry in a mortar to reduce it to a finer 

 state of comminution. It was then rubbed for several minutes at a time, with 

 successive portions of cold distilled water. The milky liquids, after settling for 

 a few minutes, were poured out of the mortar and allowed to subside farther for 

 a night, and what subsided was added to the mass of solid matter. Another por- 

 tion of water was also left a night on the powder, and well rubbed on it next day, 

 and then strained through two plies of thick muslin, and allowed to subside for 

 half an hour. The whole of the milky liquids were then boiled for a few minutes. 

 A very slight appearance of coagulation ensued, and a very little matter speedily 

 subsided, which, from the manner in which it was obtained, was evidently a trace 

 of vegetable albumen. 



The residual solid matter was now triturated with boiling water, and left all 

 night with the liquid : and this process was repeated several times with new por- 

 tions of boiling water. A milky liquid was again obtained, which remained so, 

 even after every thing mechanically suspended had been deposited by rest. 



To the emulsion which had been boiled and separated from the albumen, 

 as well as to that prepared with boiling water, acetic acid was added as long as 

 a precipitate was formed. Next day the precipitate had subsided, and the liquid 

 was clear, or very nearly so. In a day or two it was collected on a weighed 

 filter, and dried by the heat of a salt bath and weighed. Treated with ether, 

 nothing was taken up. 



This substance, from the manner in which it was procured, as well from its 

 leading characters with reagents, appeared to be either identical with, or nearly 

 allied to, legumin, or what has lately been called vegetable casein. Its solution 

 as has been seen, is not coagulated by heat, and in this respect it differs essentially 

 from albumen. On the other hand, it is precipitated by acetic acid, precisely as 

 an infusion of peas, which has deposited its starch, is precipitated by that acid. 

 Farther, it is more or less soluble in caustic potash ley, and it is an azotised sub- 



