276 



M. Janssen on the Solar Protuberances. [Feb. 4, 



In the presence of an excess of sulphuric acid, the water-molecule eli- 

 minated is without influence upon sulphoxide of carbon. 



I have still to say a few words respecting the behaviour of ethylic 

 mustard-oil with nitric acid, although the experience acquired in the 

 several experiments I have described could not possibly leave any doubt 

 on the nature of this reaction. Here, again, the ethyl-group separates, 

 united with nitrogen, in the form of ethylamine, from the molecule, while 

 the carbon and sulphur of the group C S are burnt and eliminated in the 

 form of carbonic and sulphuric acids. The same deportment is exhi- 

 bited by the homologues of ethylic mustard-oil, and also by the allyl- 

 compound. 



The products which are generated by the action of nitric acid upon 

 sulphocyanide of ethyl and its homologues are known. According to the 

 experiments of Muspratt, sulphocyanide of ethyl yields with nitric acid 

 ethyl-sulphurous acid, 



Accordingly there is also in this case elimination of the ethyl-group, in the 

 form of a sulphur-compound. 



In conclusion it may be stated that I have examined the action of 

 several other chemical agents, and more especially of the alkali-metals 

 and their hydrates, on the two classes of isomeric compounds. Most of 

 the experiments, however, which I have made in this direction are not yet 

 completed, and I will here only briefly allude to the elegant transformation 

 which sulphocyanide of ethyl suffers in contact with metallic sodium. A 

 powerful reaction ensues, cyanide of sodium and sulphide of ethyl being 



It affords me great pleasure to mention the energy and intelligence with 

 which Dr. Bulk has assisted me during the performance of the experi- 

 ments described in this paper. My best thanks are due to him. 



III. " On the Solar Protuberances." By M. Janssen. In a Letter 

 to Warren De la Rue, F.R.S. Communicated by Mr. De la 

 Hue. Received February 2, 1869. 

 " Je voulais vous ecrire depuis longtemps pour vous faire part de mes 

 travaux et vous remercier des bonnes et puissantes introductions que je 

 vous dois. J'attendais que j'eusse quelque chose de complet a vous pre- 

 senter, et j'ai ete ainsi entraine peu a peu. 



Action of Nitric Acid upon Ethylic Mustard-oil. 



formed. 



+ Na Na=2 Na C N + 



