V I ?o Mr. Dekval on the Gauje of the 



Amongfl: the natural bodies, which are the 

 objefts of this inquiry, vegetables claim GUI' 

 ► principal attention, from the gi^eat Variety and 

 brightnefs of their colours. 



In Order to examine the leaves, fruits, flowers, 

 ^ood, and roots of plants, I found it neceffary 

 to feparate their component parts, on which 

 their colours depend. 



The following experiments, made with 'this 

 view, have enabled me to difcover the caufe of 

 ■ thofe colours, and the manner in which they are 

 produced. 



I digeRed, in reflified fpirits of wine, grafs 

 and Q\\\t\ green leaves of plants : by this means 

 a tranfparent green tindure was obtained, which , 

 confided of the colouring matter, difTolved by 

 the fpirit. I filled one of the vials, (No. 28.) 

 with this liquor, and viewing that part of it which 

 was in the neck of the vial, I obferved that it 

 iVanfmitted a vivid green colour; but the other 

 part of the tinflure, which was contiguous to the 

 uncovered fide of the vial, refleded na light, 

 and confequently appeared Hack, 



I poured, into a white china cup, a fmall quan- 

 tity of this tincture, which, by its prefence, im- 

 parted to the bottom of the cup a green colour, 

 exadlly refembling that of the leaves from which 

 the matter had been extratfled. 



After the Colouring Matter had been taken 

 from the leaves, the leaves remained apparently 



unaltered 



