( 228 . ) 



Remarks on a paper hy Dr Stark, On the Influence of Colour 

 on Heat, SfC. in the Fhilos, Trans. 1833, part ii. ; and on an 

 Historical Account of Experiments relating to the subject, in 

 tlte Edinburgh New Philosophical Journal, No. 33. By 

 the Rev. Baden Powell, M. A. F.R.S., Savilian Professor 

 of Geometry, Oxford. Communicated by the Author. 



On the appearance of the part of the Philosophical Transac- 

 tions just referred to, my attention was immediately drawn to 

 the contents of Dr Stark's paper, as belonging to a subject to 

 which, some years since, I had paid particular attention. Se- 

 veral remarks occurred to me on the first perusal of it, which I 

 conceived it might not be unserviceable to the cause of scientific 

 truth to bring forward, but which circumstances have prevented 

 me from putting into a form for pubhcation till now. Since the 

 greater part was written, I have seen the same author''s paper in 

 the Edinburgh New Philosophical Journal, and in adding some 

 remarks on that paper also, my observations may perhaps be 

 found to have assumed an irregular form, which I have not now 

 time to correct. To the general doctrine maintained by Dr 

 Stark I confess I entertain considerable objections; though I 

 most readily acknowledge the interest of his researches, and the 

 skill and ability displayed in them. The subject is one which 

 certainly no previous experimenter has attempted, though I be- 

 lieve such a conclusion as Dr Stark's has often been vaguely 

 stated by writers on the subject of heat ; but this portion of the 

 science of heat seems to have been in an especial degree aban- 

 doned to inaccuracy. It, in fact, is hardly yet recognised as a 

 separate science ; and it is so slightly connected with one or two 

 other branches, that it seldom meets with any original or pre- 

 cise discussion from systematic writers on those branches. I ob- 

 serve, however, that Dr Stark's conclusion has received the sanc- 

 tion of Dr Prout in his Bridgewater Treatise ; and as it certain- 

 ly possesses much plausibility, I conceive it the more necessary 

 to explain freely the nature of my doubts in regard to it. I can 

 only hope that nothing will be found in the manner of stating 

 my objections, which can reasonably give offence to the author; 



