NUTRITION OF VEGETABLES. 



27 



Mr. Bcrtliollet mixed 30 gr. [463 grs.] of charcoal cal- 

 cinefl In a forge fire with 20 gr. [309 grs.] of sulphur, and 

 by distillation in a porcelain retort obtained more tlian 100 

 cuhie centim. [391 lines] of sulphuretted hidrogen gas : and 

 it appears to me to be probable, that, if the experiment were 

 frequently repeated with the same charcoal, it might be to- ^ 



tally decomposed, a fact that it would be interesting to 

 verify. 



If oxigen in the state of gas be presented to the charcoal 

 instead of sulphur, water is formed, as is proved by the ex- 

 periments of Lavoisier on the combustion of charcoal, as 

 well as by those of ^Ir. Ilassenfratz : and analogous results 

 are obtainable with metallic oxides, according to the obser- 

 vations of Cruikshank. 



It even appears from the nice investigations of Messrs, The diamond 

 Biot and Arrago on the refractive power of bodies, that the hidrcm, 

 diamond, which has hitherto been considered as pure car- 

 bon, must contain 'a large quantity of hidrogen, which has 

 the greatest refractive power of any substance yet observed 

 in nature. These gentlemen intend to verify their conjecture 

 by direct experiments, from which very interesting results 

 may be expected, The existence of hidrogen in the dia- 

 mond has been announced from other facts by Mr.Winterl. 



From the chief facts that have been here mentioned it 



follows : General con- 



1 . That vegetables find in pure water every thing necessary 

 for them to assimilate. 



2. Tliat vegetable mould in a state of complete decay 

 contains nothing soluble, and can only supply plants with i 

 water, which it retains abundantly in a certain state of divi- 

 sion adapted to their nourishment, ^ 



3. That vegetables can grow in any substance, provided it 

 have no action on them, and be perfectly insoluble in water. 



4. That the organic powers, assisted by the solar light, de- 

 velopes in plants substances that have been deemed simple, 

 as earths, alkalis, metals, sulphur, pb.ospl.orus, charcoal, 

 and perhaps too nitrogen, that probably will no longer con- 

 tinue to be the limits at which chemical analysis will stop, 



o. That oxigen, hidrogen, and tire appear to be the only 



ekmea- ' , 



