Ref tangibility of the inviftble Rays of the Sun. 9 



220*; their ihadows prepared with a gray or pearly colour, 

 enriched with glazing : their draperies glazed ; flefh glazed, 

 and fcumbled with rich virgin tints ; and the whole harmo- 

 nifed by the high lights being touched on with a warm yel- 

 low colour, nearly of the tone of the high lights of the flefh, 

 as in remark on No. 249 f." I cannot help adding, there 

 were not any pictures in the Orleans collection which (in 

 point of colour) looked fo agreeable as the Venetian, owing 

 to their principal mafs of colour being invariably warm ; 

 wherever the contrary occurred, the effect on the eye was 

 unpleafant ; as alfo when the great mafs was difturbed by the 

 intervention of a cold colour. 



I remain, Sir, your humble fervant, 



E. DAYES. 



Francis-ftreet, 

 April 1 1, 1800. 



The Editor of the Philofophical Magazine. 



IT. Experiments on the Rtfrangibility of the inviftble Rays of 

 the Sun. By William Herschel, LL.D.F.R.S.% 



I 



N that feftion of mv former paper which treats of radiant 

 heat, it was hinted, though from imperfeel experiments, 

 that the range of its refrangibility is probably more extenfive 

 than that of the prifmatic colours; but, having lately had 

 fome favourable funfhine, and obtained a fufficient confirm- 

 ation of the fame, it will be proper to add the following ex- 

 periments to thofe which have been given : — 



I provided a fmall ftand, with four fhort legs, and covered 

 it with white paper §. On this I drew five lines, parallel to 

 one end of the (land, at half an inch diftance from each 

 other, but fo that the firft of the lines might only be ~ of an 



* 249, Venus rifing from the fea, Titian; 211, the education of 

 Cupid, Titian ; 220, Europs, Titian, 

 t Dinna and Califto, Titian. 



J From the T'ranfaflious of the Royal Society for 1800. 

 i See Plate f. fig. 2. 



Vol. VIII. C inch 



