372 Prof. Powell's Note on the Theory of Light. 



reduced to powder. In consequence of the force with which 

 it projects the minute fragments of any containing vessel in 

 which it explodes, it is necessary that the operator should 

 wear gloves, and a close mask, furnished with thick glass 

 plates at the apertures for the eyes, and perform his manipu- 

 lations with the intervention of a moveable wooden screen*. 



In common with other aethers, the perchlorate of aethule is 

 insoluble in water, but soluble in alcohol; and its solution in 

 the latter, when sufficiently dilute, burns entirely away with- 

 out explosion. It may be kept for a length of time unchanged 

 even when in contact with water: but the addition of this 

 fluid, when employed to precipitate it from its alcoholic solu- 

 tion, causes it partially to be decomposed. Potassa, dissolved 

 in alcohol, and added to the alcoholic solution, produces im- 

 mediately an abundant precipitate of the perchlorate of that 

 base ; and, when added in sufficient quantity, decomposes the 

 aether entirely. It would appear, therefore, impracticable to 

 form either perchlorovinates or perchlorovinic acid. 



We have subjected the perchlorate of aethule to the heat of 

 boiling water with explosion or ebullition. 



It may be observed, that this is the first aether formed by 

 the combination of an inorganic acid containing more than 

 three atoms of oxygen with the oxide of aethule, and that the 

 chlorine and oxygen in the whole compound are just suf- 

 ficient to form chlorohydric acid, water, and carbonic oxide 

 with the hydrogen and carbon. 



The existence of a compound of the oxide of aethule with 

 an acid containing seven atoms of oxygen, led us to attempt to 

 combine, by the same method, this base with nitric acid. 

 For this purpose we subjected a mixture of sulphovinate 

 and nitrate of barytes to the same treatment as described 

 above ; but the reaction, even when conducted with the great- 

 est possible care, is destructive, hyponitrous aether and gaseous 

 matters being the principal products obtained. Nor were we 

 more successful in our attempts to procure a sulphurous or 

 hyposulphuric aether by the same process. 



LIII. Note on the Theory of Light. By Professor PowiSLLf. 



T N my recently published work * On the Undulatory Theory 

 -*■ as applied to the Dispersion of Light,' &c, I have given 

 abstracts of the various investigations related to the main sub- 



* Having suffered severely, on several occasions, from the unexpected ex- 

 plosion of this substance, we would earnestly recommend the operator not 

 to neglect the precautions mentioned above. 



f Communicated by the Author. 



