1868.] 



of E thy lie Mustard-oil. 



73 



The reactions occur in the inverse order when sulphocyanide of methyl is 

 produced. Here the process commences with the reaction between bisul- 

 phide of carbon and ammonia, hydrosulphocyanic acid being formed with 

 separation of sulphuretted hydrogen. 



C S 2 +H 3 N=H 2 S-f-CHNS. 



Hydrosulphocyanic acid and methylic alcohol, lastly, furnish water and 

 sulphocyanide of methyl. 



CHN8 + CH 4 = H 2 + C 3 H 3 NS. 



This inverse order, in which the reactions succeed each other, gives a de- 

 finite direction to our speculations as to the arrangement of the atoms 

 within the molecules of the two compounds. If bisulphide of carbon, 

 S C S, in contact with methylamine, H 3 C N H a> is found to disengage 

 sulphuretted hydrogen, we cannot doubt that the carbon-atom of the bisul- 

 phide, meeting, as it were, with its two freed attraction-units those liberated 

 in the nitrogen atom, associates with this nitrogen-atom, and consequently 

 that it must be by the nitrogen that the carbon of the methyl-group is 

 chained to trie carbon of the bisulphide. On the other hand, if in hydro- 

 sulphocyanic acid we may conceive the hydrogen to be in union with the sul- 

 phur, we are, after this hydrogen has been converted into water by the hy- 

 droxyl of methylic alcohol, also justified in considering the sulphur-atom as 

 the link of connexion between the two carbon-atoms of the compound, the 

 attraction-unit, w 7 hich lias become available in the carbon-atom, being satu- 

 rated by the free atomic power of the sulphur. The relative position of 

 the atoms in the molecules of the two compounds would thus be indicated 

 by the following diagram — ■ 



Methylic mustard-oil. Sulphocyanide of methyl. 



H II 



I I 

 H — C — N = C = S, and H— C— S— C=N ; 



I I 

 H H 



or more concisely in the subjoined formulae — 



H 3 C \ N H 3 C 1 „ 



If this conception be correct, it is obvious that whenever nitrogen and 

 sulphur are found together in a molecule, this molecule must be capable 

 of existing in two different forms, one corresponding to methylic mustard- 

 oil, the other to cyanide of methyl. 



In a paper which I hope shortly to submit to the Royal Society, I pro- 

 pose to show how far this conception is supported by experiment. 



