996 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



being very pale greenish-yellow, and the darkest, brown with a faint tint of green ; the 

 chief intermediate shades being grass-green and pale and deep olive-green. The lighter 

 coloured ether extracts were usually derived from the later percolates, and the dark 

 coloured from the earlier percolates of the same seeds. The extract is translucent and 

 clear, but after standing for some time a nearly colourless sediment usually separates, which 

 disappears when the extract is heated to 120° F. Ethyl alcohol, amyl alcohol, acetone, 

 chloroform, ethyl and petroleum ether, and bisulphide of carbon dissolve the extract freely. 

 It has an oleaginous odour, and when dissolved in ether and washed by shaking several 

 times with water, it has an oleaginous taste without bitterness. The well- washed ether 

 extract does not possess any toxic action, nor indeed any other action than that of a 

 bland oil. Its viscosity, and in the paler specimens, its appearance and other characters, 

 are very similar to those of olive oil. The specific gravity, determined in a pale yellow 

 or greenish-yellow oil, was found to be 0'975, in a pale green oil 0*954, and in a dark 

 greenish-brown oil 0'9267. The two former or light-coloured oils, when heated to 120° F., 

 and then allowed to cool to the temperature of the laboratory (about 60° F.), became 

 semi-solid and uniformly opaque, although previously to this heating they had remained 

 for more than twelve months liquid, and, with the exception of a slight deposit, clear 

 and translucent, in the same laboratory. When microscopically examined in the opaque 

 condition, the oil was found to contain numerous small aggregations of slender, needle- 

 shaped crystals. 



In several of the analyses, when the ethereal solution of the oil and other substances 

 was shaken with water a thick and persistent emulsion or magma was produced, from 

 which, however, the greater portion of the ether, holding oil and chlorophyll in solution, 

 gradually separated itself. After this emulsion had been decanted and washed by shaking 

 with ether, it was found to contain a small quantity of active principle and of resin, and 

 a considerable quantity of mucilage and of a substance possessing the characters of 

 caoutchouc. While, as will afterwards be stated, neither common or anhydrous ethyl 

 ether dissolve appreciable quantities of the previously separated active principle, when 

 the seeds are percolated with ether, or when the alcoholic extract mixed with water is 

 shaken with ether, a very small quantity of the active principle appears in the ethereal 

 solution. It may, however, be entirely removed from the ethereal solution by shaking it 

 several times with water. 



Alcohol Extract. 



On evaporating, with the aid of a gentle heat, the concentrated tincture of the seeds 

 previously freed from substances soluble in ether, or a watery solution of this tincture, a 

 sweetish mucilaginous and somewhat nutty odour is developed. The extract then assumes 

 the appearance of a translucent brownish-yellow or yellowish-brown hard substance, 

 having some tenacity. If it be further dried by being placed in vacuo over sulphuric acid, 

 it gradually loses its translucency, and becomes opaque, lighter in colour, and brittle. 

 The extract is intensely bitter. It is freely soluble in water and in rectified spirit, 



