234 Dr. A. W. Hofmann on the Phosphorus Bases. [Mar. 21, 



are, however, obviously, in consequence of the volatility and oxidability of 

 the compound, far less persistent. The vapour of ethylphosphine bleaches 

 cork like chlorine ; very peculiar, too, is its action on caoutchouc, which in 

 contact with it becomes translucent, losing its elasticity. Chlorine, bromine, 

 and nitric acid inflame the compound. Ethylphosphine combines with 

 sulphur and carbon bisulphide, though far less energetically than tri- 

 ethylphosphine ; nor are the compounds thus produced crystalline, like the 

 corresponding derivative of triethylphosphine j as yet they are but im- 

 perfectly studied. 



Like the monomethylated base, ethylphosphine unites with chlor-, brom-, 

 and iodhydric acids to saline compounds. The solution of the chlor- 

 hydrate yields with platinum perchloride a double salt, crystallizing in 

 fine crimson-red needles, which resemble freshly prepared chromic acid. 

 The most beautiful salt of ethylphosphine is the iodhydrate. It forms 

 white four-sided tables, which, in a current of hydrogen, may be sublimed 

 even at the temperature of boiling water. The aspect of the substance 

 forcibly recalls that of ordinary sal ammoniac. Analysis showed that 

 this salt possesses the composition assigned to it by theory, viz. : — 

 C 2 H 8 PI = (C 2 H 5 ) H 2 P . HI. 



The iodhydrate easily dissolves in water, but not without being entirely 

 decomposed. In dry air the crystals of the salt are permanent ; but even 

 when breathed upon they are altered, the decomposition being indicated 

 by the powerful odour emanating from the salt, which, when dry, is 

 perfectly inodorous. When a crystal is thrown upon water, it is seen to 

 disappear with evolution of gas. Alcohol dissolves the iodhydrate, but 

 only with partial decomposition ; in ether it is insoluble. The only sol- 

 vent in which the salt was found to be soluble, though likewise but 

 sparingly, is concentrated iodhydric acid. Addition of ether to this solu- 

 tion causes the salt to separate in large, well-formed tables, having often a 

 length of 1 centimetre ; they are generally very thin, their surface pre- 

 senting magnificent iridescence. 



Diethylphosphine. 



C 4 H u P = C a H 5 P. 



H J 



Transparent, colourless, perfectly neutral, mobile liquid, floating upon 

 water, in which it is insoluble, powerfully refracting light. It boils con- 

 stantly at 85°, i. e. 60° higher than the primary base. The odour is pe- 

 netrating and most persistent, very different from that of ethylphosphine, 

 distantly resembling that of triethylphosphine. The diethylated com- 

 pound attracts oxygen with far more energy than the primary base ; and 

 more than once have I seen this compound bursting into flame on opening 

 a bottle. Diethylphosphine combines with sulphur and carbon bisulphide ; 

 these combinations, like those of the monoethylated base, are liquids. 



