The Chemical Statics of Organised Beings. 57 



sented by twelve molecules of carbon united to ten molecules 

 of water. 



The ligneous part which is insoluble in water, the starch, 

 which gelatinises (l'amidon, qui fait empois) in boiling water, 

 and the dextrine which dissolves so easily in water cold or 

 hot, constitute therefore, as M, Payen has so well proved, three 

 bodies possessing exactly the same composition, but diversified 

 by a different molecular arrangement. 



Thus, with the same elements, in the same proportions, ve- 

 getable nature produces the insoluble walls of the cells of 

 cellular tissue and of the vessels, or the starch which she ac- 

 cumulates as nourishment around buds and embryos, .or the 

 soluble dextrine which the sap can convey from one place to 

 another for the wants of the plant. 



How admirable is this fecundity, which out of the same body 

 can make three different ones, and which allows of their being 

 changed one into the other, with the slightest expense of force, 

 every time occasion requires it ! 



It is also by means of carbon united with water, that the 

 saccharine matters so frequently deposited in the organs of 

 plants for peculiar purposes, which we shall shortly mention, 

 are produced. Twelve molecules of carbon and eleven mo- 

 lecules of water form the cane sugar. Twelve molecules of 

 carbon and fifteen molecules of water make the sugar of the 

 grape. 



These ligneous, amylaceous, gummy, and saccharine matters, 

 which carbon, taken in its nascent state, can produce by uniting 

 with water, play so large a part in the life of plants, that, when 

 they are taken into consideration, it is no longer difficult to 

 understand the important part that the decomposition of car- 

 bonic acid performs in plants. 



Hydrogen. — In the same manner that plants decompose car- 

 bonic acid for the appi'opriation of its carbon, and in order to 

 form together with it all the neutral bodies which compose nearly 

 their entire mass ; in the same way, and for certain products 

 which they form in less abundance, plants decompose water and 

 fix its hydrogen. This appears clearly from M. Boussingault's 

 experiments on the vegetation of peas in closed vessels. It is 

 still more evident from the production of fat or volatile oils so 

 frequent in certain parts of plants, and always so rich in hydrogen. 

 This can only come from water, for the plant receives no other 

 hydrogenated product than the water itself. 



These hydrogenated bodies, to which the fixation of the 

 hydrogen borrowed from the water gives birth, are employed by 

 plants for accessory uses. They form, indeed, the volatile oils 

 which serve for defence against the ravages of insects ; fat oils or 

 fats, which surround the seed, and which serve to develope heat 



