542 Royal Society : — 



tion of an easily accessible derivative of methyl-aldehyde possessing 

 a characteristic composition, and the analysis of which would not 

 be less conclusive than that of the aldehyde itself. The slight solu- 

 bility and the powerfully crystalline tendencies of the sulphaldehyde 

 of the ethyl-series could not fail to indicate the direction in which I 

 had a right to hope that the object which I was aiming at might be 

 accomplished. 



If a current of sulphuretted hydrogen be passed through the me- 

 thyl-alcoholic solution of methyl-aldehyde, the liquid becomes tur- 

 bid after a few minutes, and on allowing the saturated solution to 

 stand for some hours, a body of an alliaceous odour begins to be 

 separated at the bottom of the flask. If the liquid be now mixed 

 with half its volume of concentrated hydrochloric acid, and heated 

 to ebullition, it becomes limpid, and solidifies on cooling into a mass 

 of felted needles of dazzling whiteness. These needles fuse at 218° ; 

 they are volatile without decomposition. Slightly soluble in water, 

 they are more readily dissolved by alcohol, and still more so by ether. 

 For the purpose of analysis they were recrystallized from boiling 

 water, in order to exclude free sulphur, with which they might have 

 possibly been contaminated. The numbers obtained in the ana- 

 lysis of the crystals unmistakeably establish their nature. The white 

 crystals, as might have been expected, have the composition of the 

 sulphaldehyde of the methyl-series, 



CH 2 S. 



The analysis of the sulphur-compound fixes, of course, the pre- 

 sence of the corresponding oxygen compound among the products of 

 the slow combustion of methylic alcohol. 



A more minute examination of methylic aldehyde and its deri- 

 vatives remains still to be made. It will be absolutely necessary 

 to isolate the oxygen-term and to determine its vapour-density, in 

 order to ascertain its molecular weight. If we remember the facility 

 with which the aldehydes are polimerized, the question presents 

 itself, whether the aldehyde formed by the slow combustion of me- 

 thylic alcohol is represented by the formula 



CH.O, 



or a multiple thereof. A similar remark applies to the sulphur-deri- 

 vative. It deserves, moreover, to be mentioned that a compound 

 isomeric with methylic aldehyde, the dioxymethylene (C 3 H 4 O a ) 

 of M. Boutlerow, is known already ; also that a sulphur-compound 

 of the formula 



CH 2 S 



has been obtained by M. Aime Girard, who observed that bisulphide 

 of carbon is reduced by the action of nascent hydrogen with disen- 

 gagement of sulphuretted hydrogen. 



In the course of next winter I propose to perform some farther 

 experiments on the product of the slow combustion of methylic 

 alcohol for the purpose, if possible, of isolating methylic aldehyde in 

 a state of purity, and of thus completing this inquiry. 



