HEDYCHIUM. 75- 



ones set on edge. A few of the cells contain resin and essential 

 oil. The epidermis is composed of several rows of compressed,, 

 nearly empty, reddish -brown cells. From the unaltered condition 

 of the starch it appears that the rhizomes are not exposed to heat 

 in drying. 



A chemical examination of the root was made by Dr. Thresh*^ 

 which proved that the odorous principle exists but in very 

 minute proportion, and to isolate it in a state of purity would 

 necessitate working on a large quantity of material ; but in the 

 state in which he did eliminate it, combined with a small quantity 

 of fixed oil, it was very powerful. He says, "a very small 

 quantity being dropped upon the clothes, renders them highly 

 odorous for a considerable length of time, or if exposed, causes a 

 large room to be pervaded with an odour recalling that of 

 hyacincths." Describing the method of extraction, he says that 

 the odorous principle was entirely taken up by petroleum ether. 

 Dry ether exhausted the rhizome more readily, but extracted little 

 or nothing which was not soluble in the petroleum, and as 

 certain constituents of the plant were found to be more readily 

 isolated from the petroleum solution, the whole of the sample 

 w^as treated therewith. Upon allowing the petroleum ether to 

 evaporate slowly, an abundant crop of large, colourless, tabular 

 crystals was obtained, together with a pale yellowish-brown oily 

 fluid. These crystals, after washing with cold petroleum, were 

 submitted to a series of re-crystallizations in order to remove traces 

 of the odorous matter. They were finally quite odourless, and 

 found to possess the following properties : — Soluble in petroleum 

 ether, ether, alcohol, chloroform and benzene. Insoluble in diluted 

 solutions of potasli, soda or ammonia. Sulphuric acid dissolved it 

 in the cold without production of colour, but if heated the 

 solution became purple red. The alcoholic solution was neutral 

 in reaction, not coloured by ferric chloride or precipitated by basic 

 lead acetate, neither did it reduce silver salts. The melting point 

 was found to be 49° C, and after melting it would remain fluid 

 at ordinary temperatures for days if left undisturbed. The vapour 

 density could not be ascertained, as it was found that at the temper- 

 ature necessary to vaporise it, dissociation took place. By 

 combustion with oxide of copper in a current of oxygen, the 



* Phaim. Joura. [3], xv. p. 361. 



