42-L New Outlines of Chemical Philosophy. 



bent towards a perpendicular. The letters HK represent the 

 prismatic focus: for as the quantity of heat and light contained 

 in the space FG is by the refracting ]ooucr of the prism conveyed 

 into the smaller space HK; consequently HK must be more lu- 

 minous and calorific than FG. In my next paper I shall en- 

 deavour to show why the red rays are more calorific than the 

 green or violet, &c. 



Exp. 5. — June 23, 18U, at half past two in the afternoon, 

 the sun shining through an open window fronting the west, I 

 placed a highly sensible and correct thermometer (made by I\Ir. 

 Bath of the Cork Institution) on a sheet of white paper, resting 

 horizontally on a writing-table. In five minutes it rose in the 

 full sun-beams to S2|; and after remaining for some time sta- 

 tionary, I held a large prism at about one inch distance imme- 

 diately over it, and in such a manner as to convey the rays of 

 light as much as possible to the prismatic focus, and also to 

 immerse the entire thermometric bulb and cylinder in a spec- 

 trum of transmitted light. 1 need scarcely again remark that 

 this spectrum was composed of medion white light, bounded on 

 the one side by orange and yellow, and on the other by blue and 

 violet. In five minutes the thermometer rose to 101; or, in other 

 words, the transmitted light was heated IS|° above the full suu- 

 shine by passing through the jnism. On removing the prism 

 the thermometer fell in five minutes to 85°; and on again im- 

 mersing it in the spectric light it rose to 101°. About half past 

 three I ended these experiments, simple in their manipulation, 

 and obvious in their inferences. 



Sir, I beg leave to remain 



Your obedient servant, 

 Cork, May 4, 1815. JoSEPH ReaDE, M.D. 



LXXIV. Neiu Outlines, of Chemical Philosophy. 



By Ez. Walker, Esq, of Lynn, Norfolk. 



[Continued from p. 21.] 



J; ROM the discordant opinions which prevail among the writers 

 on electricity, it appears that this branch of physics is still very 

 far from being clearly understood. It has been generally sup- 

 posed, that where no spark is elicited, no permanent effect is pro- 

 duced upon an insulated conducting body. 



But tlie truth is, that most of the operations of nature, in 

 which electricity is concerned, are produced by inducted electric 

 city; and consequently, the eifects of those elements on matter 

 become an interesting suljject of philosophical discussion. 



Ill order to investigate the laws of electrical phcenomena, with 



that 



