[ 266 ] 



(NOTE I.) 



We may here note, that phofphorifed hydrogene gas (a difcovery afcribed to 

 C. Gengembre) poflefles the fingular property of inflaming by the contaft of air 

 alone, without requiring its temperature to be raifed, or an ignited body to be 

 prefented to it. But whether this fpecies of gas is capable of communicating the 

 green colour to vegetables, and whether it is generated in the atraofphere, or 

 earth, are queflions to which I am not here prepared to give aiifwers of a fati^- 

 faftory nature. 



(NOTE 2.) 



The ancient Greeks afcribed the green colour of vegetables to the influence of 

 folar light ; but they explained this opinion by a theory, the fubflance of vi^hich 

 is as follows: « There are but three fimple colours, white, black, and yellow. 

 Thele depend on the elements : white, on the air, water, and earth ; yellow, 

 on fire, or the inflammable principle ; black, on a want of light. The mixture 

 of the elements may occafion different colours. Thus from the conjunftion of 

 ■water with the rays of the fun, vegetables acquire a j>reen : when earth and 

 .water co-operate without the influence of light, they aflunie only white, whiifl: 

 thofe parts of the plant which rife out of the earth are green.' Hence it 

 appears, that the Greeks had, on this fubjeft, ideas fimilar to thofe which 

 are fupported by Meflrs. Ingenhoufz, Sennebier, Humboldt, &c. Here then we 

 ■have caufe to alt, in the words of the eloquent Preacher, pronounced near 

 ;3ao years ago : < Is there any thing whereof it may be faid. See, this is 

 nciu ."' 



(NOTE 3.) 



