Sometimes asafœtida is imported as a fluid honey-like mass, apparently pure. We presume that such is that of the first gathering, which Kämpfer says is called milk. The drug is often adulterated with earthy matter which renders it very ponderous; it must be granted that an addition of such matters may often be necessary in order to enable the drug to be transported. This earthy or stony asafœtida constitutes at Bombay a distinct article of commerce under the name of Hingra.
By exposure to air, asafœtida acquires a bright pink and then a brown hue. The perfectly pure tears display when fractured a conchoidal surface, which changes from milky white to purplish pink in the course of some hours. If a tear is touched with nitric acid sp. gr. 1·2, it assumes for a short time a fine green colour.
When asafœtida is rubbed in a mortar with oil of vitriol, then diluted with water and neutralized, the slightly coloured solution exhibits a bluish fluorescence. The same will be observed, to some extent, if tears of the drug are immersed in water and a little ammonia is added. The tears of asafœtida when warmed become adhesive, but by cold are rendered so brittle that they may be powdered. With water they easily form a white emulsion.
The drug has a powerful and persistent alliaceous odour and a bitter acrid alliaceous taste.
Chemical Composition—Asafœtida consists of resin, gum and essential oil, in varying proportions, but the resin generally amounting to more than one-half.
As to the oil, we have repeatedly obtained from 6 to 9 per cent. by distilling it from common copper stills. It is light yellow, has a repulsive, very pungent odour of asafœtida, tastes at first mild, then irritating, but does not stimulate like oil of mustard when applied to the skin. It is neutral, but after exposure to the air acquires an acid reaction and different odour; it evolves sulphuretted hydrogen. In the fresh state, the oil is free from oxygen; it begins to boil at 135° to 140° C., but with continued evolution of hydrogen sulphide, so that we did not succeed in preparing it of constant composition, the amount of sulphur varying from 20 to 25 per cent. We found it to have a sp. gr. of 0·951 at 25°, and a strong dextrogyrate power. If one drop of it is allowed to float on water it assumes a fine violet hue by vapours of bromine.
The essential oil of asafœtida submitted to fractional distillation yielded us, at 300°, a considerable proportion of a most beautifully blue coloured oil. By very cautiously oxidizing the crude oil, we obtained a small amount of extremely deliquescent crystals of a sulphonic acid. Sodium or potassium decomposes the oil with evolution of gas, forming potassium sulphide; the residual oil is found to have the odour of cinnamon.
The resin of asafœtida is not wholly soluble in ether or in chloroform, but dissolves with decomposition in warm concentrated nitric acid. It contains a little Ferulaic Acid,
| C₆H₃ |  | OCH₃ |  | CH·CH·COOH, |
| OH |
discovered by Hlasiwetz and Barth in 1866, crystallizing in iridescent needles soluble in boiling water; it is homologous with Eugetic Acid,