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mother-liquor of the sulphide of triethylphospine is distinctly alkaline, 

 and yields, after the necessary operations, on addition of dichloride of 

 platinum, the well-known octohedral platinum-salt of methyl-triethyl- 

 phosphonium. On further evaporating the liquid from which these 

 crystals had been obtained, the six-sided tables of the platinum-salt 

 of oxide of triethylphosphine were deposited. 



The principal products of the action of water upon the red crystals, 

 then, are sulphide of triethylphosphine, oxide of triethylphosphine, 

 hydrate of methyl-triethylphosphonium, and disulphide of carbon, 

 which may be partly or entirely converted into sulphuretted hydrogen 

 and carbonic acid. Four molecules of the disulphide of carbon- 

 compound, and two molecules of water, contain the elements of two 

 molecules of the sulphide, one molecule of the oxide, one molecule of 

 the hydrated phosphonium, and three molecules of disulphide of 

 carbon : 



(C 2 H 5 ) 3 PO + !} 2 s3 O + 3 C S 2 . 



Whilst engaged with the experiments involved in the elucidation of 

 this subject, I observed occasionally small well-defined yellow crystals 

 disseminated among the mixture of white and red needles, which 

 were deposited when the digestion-tubes were allowed to cool before 

 the transformation was terminated. The yellow crystals appeared in 

 greater quantity towards the close of the operation, but were even 

 under the most favourable circumstances obtained only in extremely 

 minute quantity. 



These crystals are almost insoluble in ether, and may therefore be 

 readily separated from the sulphide of triethylphosphine with which 

 they are contaminated. Crystallization from boiling absolute alcohol 

 furnishes them in a state of perfect purity, occasioning, however, a 

 certain loss, which may become very considerable if ebullition be 

 continued for some time. This substance is decomposed at 100, and 

 had therefore to be dried for analysis, in vacuo, over sulphuric acid. 



The yellow crystals were found to contain 

 C 8 H 17 PS 3 . 



The formation of a compound of this formula by the action of 

 water upon the red crystals is easily understood, if we recollect the 



x 2 



