868.] On Homologues and Analogues of Et hylic Mustard- oil. 67 



It is not improbable that ethylic and methylic sulphides, &c, when treated 

 with concentrated sulphuric acid, would form corresponding compounds. 



I cannot conclude this paper without acknowledging the very efficient 

 aid I have received from my assistant, Mr. Charles E. Groves, in the pre- 

 ceding investigation. 



IV. "Compounds Isomeric with the Sulphocyanic Ethers. — II. Homo- 

 logues and Analogues of Ethylic Mustard-oil." By A. W. Hof- 

 mann, Ph.D., M.D., LL,D. Received September 11, 1868. 



In a former liote submitted to the Royal Society some months ago*, I 

 have sketched a series of compounds isomeric with the well-known sulpho- 

 cyanic ethers ; today I shall endeavour to delineate more in detail the 

 bodies the existence of which I then pointed out. 



In order to prepare these substances, which, from their analogy with 

 the essential oil of mustard-seed, I have designated by the name of 

 mustard-oils, the monamines were in the first place treated with bisul- 

 phide of carbon; the alcohol-sulphocarbonates of the monamines thus 

 formed were then submitted to the action of heat and converted, by the 

 loss of 1 molecule of sulphuretted hydrogen, into sulphuretted ureas, which 

 were finally deprived of 1 molecule of monamine by means of anhydrous 

 phosphoric acid. Circuitous as this process may appear, it has the merit 

 of being a general one, furnishing, in fact, the mustard-oils both of the 

 fatty and aromatic series. When working with fatty substances, however, 

 the method may be very considerably curtailed. Let it be ethylic mustard- 

 oil that is to be prepared. 



Even on the threshhold of my inquiry I had hoped to see ethyl-sulpho- 

 carbamic acid split up into sulphuretted hydrogen and ethylic mustard-oil ; 

 experiment, however, proved that the metamorphosis assumes another 

 form, the acid yielding as products of decomposition its two components, 

 ethylamine and bisulphide of carbon. 



(CSrCC^N.Hj^ C 2 H : } N + Cg2 . 



But a transformation which the free acid refuses, the metallic ethyl- 

 sulphocarbamates undergo without difficulty, more especially in the pre- 

 sence of an excess of the metallic solution, a metallic sulphide being 

 formed. 



(C S)"(C a H.) N, H 1 g C 2 H, 1 N M 1 g 



On adding, for instance, nitrate of silver to a solution of ethyl-sulphocar- 

 bamate of ethylamine, such as is produced by the action of bisulphide of car- 

 bon upon ethylamine, a white precipitate of ethyl-sulphocarbamate of silver 

 is formed, nitrate of ethylamine passing into solution. After some time, 



* Proceedings, vol. xvi. p. 254. 



F 2 



