Mr. Daniell on the Radiation of Heat. 305 



Art. IX. On the Radiation of Heat in the Atmosphere ; in 

 reply to Mons. Gay-Lussac. By J. F. Daniell, F.R.S. 



Mous. Gay-Lussac has done me the honour to announce, in the 

 Annates de Chimie for August, 1824, his intention of submitting the 

 different chapters of my Meteorological Essays to a detailed exa- 

 mination. i>iothing could give me greater pleasure than the ful- 

 filment of this promise ; for I am aware that I have ventured, in 

 that work, to propose many novel opinions, which I can only hope 

 to see established after a full and candid discussion. He has com- 

 raenced the task with the Essay upon the Radiation of Heat in the 

 Atmosphere ; and this not being the first, either in place or import- 

 ance, naturally suggests an inquiry as to the reason of the selection. 

 Three numbers of the Annates have since been published without 

 resuming the subject ; and this interval, together with the want of 

 candour which, it grieves me to say, I shall presently have occasion 

 to expose, suggest the idea that the Reviewer was content with an 

 impression which he conceived it was easier to produce through 

 this channel than that of any of the others. Mons. Gay-Lussac 

 has formerly treated me discourteously, upon the subject of the 

 hygrometer, and flippantly upon the present occasion ; but, in my 

 reply, I shall endeavour not to forget that it is one of the first phi- 

 losophers of the age who has condescended to enter the lists against 

 me, and one for whose talents and acquirements I have the sincerest 

 admiration and respect. 



Mons. Gay-Lussac, by fixing upon one expression in ray paper, 

 has made it appear, to those who will look no further than his re- 

 view to form their opinions (and many such there are), that I have 

 advanced certain most untenable conclusions with confidence and 

 ■presumption. It will scarcely, therefore, be believed by them that 

 I have taken more than ordinary pains to guard against any such 

 imputation. I have expressly stated, that I was sensible that 

 ** my observations were in a very imperfect state; and that I only 

 ventured to bring them forward in the hope of exciting some atten- 

 tion to a subject which appeared to me to be well worthy of eluci- 



