2/6 Experiments on Light, [April, 



RESULTS. 



Prevailing Winds : in the former part of the month, Easterly j in 

 the latter. Northerly and North-West, 



Barometer : Greatest height 30*16 inches j 



Least 28-40 



Mean of the period 29*54 



Tliermometer : Greatest height 48° 



Least 14 



Mean of the period 31-83S 



Rain, and snow (when melted) 11 '4 inches. 



*^* The Editor has received Mr. Fox's communication with 

 pleasure. Together with Dr. Clarke's, it will make us better ac- 

 quainted than we are at present with the south coast of England. 

 He conceives that a quarterly or half-yearly report would be more 

 interesting than a monthly one. It would have this additional 

 advantage, that we should be better enabled to give it a place in the 

 Annnls of Philosophy ; and this is a consideration of importance, as 

 we are already at a loss to find room for the valuable communica- 

 tions with which we are favoured ; an evil which will not be dimi- 

 nished as the work becomes more generally known. — T. 



Article VII. 



Experiments tending to prove that iieither Sir Isaac Newton, Dr. 

 Herschel, Sir H. Davy, Mr. Leslie, Sir H. Englefield, nor any 

 other Person, ever decomposed incident or impingent Light intc 

 the Prismatic Colotirs. By Joseph Reade, M.D. 



(To Dr. Thomson.) 



SIR, Cork, Jan. 24, 18U. 



Siu Isaac Newton, for the purpose of decomposing light, 

 made a small hole in his window-shutter ^ of an inch in diameter ; 

 and having placed a prism so as to refract and receive a spectrum 

 on a sheet of white paper, perceived seven colours in the following 

 order, viz. red, orange, yellow, green, blue, indigo, and violet; 

 these he supposed to be primary colours, which, when combined in 

 certain proportions, gave white or transparent light. The necessary 

 shortness of a letter will not allow me to enumerate his experiment: 

 I therefore refer to his Optics. That this philosopher was mistaken 

 in supposing he analysed incident light will appear evident from the 

 following experiments and observations. Whc^fi we look with a 

 prism at a window, the light passes through thv. panes, and likewise 

 tiirough the prism to the eyc^ undecomposed, and consequently^- 



