236 Intelligence and Miscellaneous Articles. 



of sulphuric acid 40 + 1 equivalent of carburetted hydrogen 7, si- 

 milar to that formed by the action of anhydrous sulphuric acid on 

 olefiant gas. — Ann. de Chim. et de Phys., t. lxxii. 



ON HELLENIN. BY M. C. GERHARDT. 



This substance, obtained from Inula hellenium, is to be distin- 

 guished from inulin yielded by the same root. It is readily obtained 

 by treating the fresh root of the elecampane with alcohol of sp. gr. 

 0837 ; when the excess of alcohol is separated by distillation, the 

 concentrated liquor becomes milky by cooling, and deposits abun- 

 dance of crystals. They are purified by redissolving in alcohol and 

 recrystallizing. When the root is distilled with water, downy 

 flocculi, which are very white pure hellenin, are obtained in the 

 receiver ; but the quantity is so small that it is better to employ 

 alcohol. 



Hellenin crystallizes in four-sided prisms; they are perfectly 

 white, their smell and taste is extremely weak, and they are lighter 

 than water. They are insoluble in water, but very soluble in aether 

 and alcohol, and these solutions are precipitated by water. It dis- 

 solves also in all proportions, in essential oils and in creasote. It 

 may readily be pulverized when it is rendered impure by the resin, 

 which always exists with it in the root. Its fusing point is about 

 161° Fahr. ; it boils at 527° to 536°, and volatilizes before it boils, 

 exhaling a very weak odour. At this temperature, however, it is 

 more or less altered, so that the density of its vapour cannot be 

 ascertained. 



When hellenin is fused at a gentle heat, it recrystallizes in a 

 mass on cooling ; but if the heat be continued for some minutes, 

 the mass on solidifying does not possess a crystalline texture, but 

 resembles resin in appearance. The caustic alkalies do not decom- 

 pose hellenin, even when heated, a property which it possesses in 

 common with several substances, such as camphor, the oil of ani- 

 seed, mint, &c. On heating it in a solution of potash, it first fuses 

 and eventually dissolves, and on the addition of hydrochloric acid 

 the hellenin is precipitated without alteration. When heated with 

 hydrate of potash, a great part of it is volatilized, whilst another 

 portion is carbonized ; on dissolving the mixture afterwards in water 

 a slightly brown coloured liquid is obtained, which becomes slightly 

 turbid on the addition of acids. 



Acids act upon hellenin as they do upon the greater part of the 

 essential oils ; concentrated sulphuric acid dissolves it at common 

 temperatures, forming a red coloured solution, without the evolu- 

 tion of any sulphurous acid, provided no heat be employed ; never- 

 theless after a considerable time the mixture becomes black, as if 

 acted upon by heat. The solution then contains a certain quantity 

 of a peculiar acid, to which M. Gerhardt has given the name of sul- 

 pho-hellenic acid. 



When hydrochloric acid gas is brought into contact with hellenin, 

 it absorbs a large quantity of the gas, and a liquid of a violet co- 



