350 Prof. Lamont on Dalton's Theory of Vapour, 



be oxygen packed into groups of atoms, which encounter vast 

 resistance in moving through the ether. I sought to decide the 

 question whether it is oxygen or a~compound of hydrogen, in the 

 following: way. Heat destroys ozone. If it were oxygen only, 

 heat would convert it into the common gas ; if it were the hydro- 

 gen compound which some chemists consider it to be, heat would 

 convert it into oxygen plus aqueous vapour. The gas alone 

 admitted into my tube would give the neutral action of oxygen, 

 but the gas plus the aqueous vapour I hoped might give a sen- 

 sibly greater action. I caused the dry electrolytic gas to pass 

 through a glass tube heated to redness direct into the experi- 

 mental tube. I afterwards introduced a drying-tube between the 

 place where the gas was heated and the experimental tube. 

 Hitherto I have not been able to establish with certainty a dif- 

 ference between the dried and undried gas. Previously to heat- 

 ing, the electrolytic oxygen had been scrupulously dried; if the 

 act of heating developed aqueous vapour, I can only say that the 

 experimental means which I have employed are unable to detect 

 it. For the present, therefore, I hold the belief that ozone is 

 produced by the packing of the atoms of elementary oxygen into 

 oscillating groups — and that heating dissolves the bond of union 

 and allows the atoms to swing singly, thus disqualifying them 

 for either intercepting or generating the motion which as systems 

 they were competent to intercept and generate. 



[To be continued.] 



XLVI. Dalton's Theory of Vapour, and its Application to the 

 Aqueous Vapour of the Atmosphere. (Extract of a Letter 

 from Professor Lamoxt to Professor Kamtz at Dorpat, dated 

 Munich, August 28, 1862.) 



To the Editors of the Philosophical Magazine and Journal. 



Royal Observatory. Greenwich, 

 Gentlemen, October 11, 1862. 



THE paper, of which I enclose a translation, has been circu- 

 lated in a printed form by Dr. Lamont. The importance 

 of the subject in reference to all meteorological inquiries, espe- 

 cially to those on the broad scale, may, I trust, be accepted as 

 my excuse for submitting it for publication in the Philosophical 

 Magazine. 



As far as observations have enabled me to form an opinion, I 

 assent entirely to the views of Dr. Lamont. 



For the translation itself, I am indebted to the friendly assist- 

 ance of W. T. Lynn, Esq., Assistant of the Royal Observatory. 



I am, Gentlemen, 



Your obedient Servant, 



G. B. Airy. 



