462 M, Dumas on the Chemical Statics of Organized Beings. 



the solar heat, which decomposed carbonic acid and water, all 

 at once changes its course. It burns "carbon and hydrogen ; 

 it produces heat, that is to say, it takes to itself the principal 

 characters of animal life. 



But here a remarkable circumstance reveals itself. If barley 

 or wheat is made to germinate, much heat, carbonic acid and 

 water are produced. The starch of these grains first changes 

 into gum, then into sugar, then it disappears in producing 

 carbonic acid, which the germ is to assimilate. Does a potato 

 germinate, here also it is its starch which changes into dex- 

 trine, then into sugar, and which at last produces carbonic 

 acid and heat. Sugar, therefore, seems the agent by means 

 of which plants develop heat as they need it. 



How is it possible not to be struck from this with the 

 coincidence of the following facts? — Fecundation is always ac- 

 companied by heat ; flowers as they breathe produce carbonic 

 acid. They therefore consume carbon ; and if we ask whence 

 this carbon comes, we see in the sugar cane, for example, that 

 the sugar accumulated in the stalk has entirely disappeared 

 when the flowering and fructification are accomplished. In 

 the beet root, the sugar continues increasing in the roots until 

 it flowers ; the seed-bearing beet contains no trace of sugar 

 in its root. In the parsnep, the turnip and the carrot, the 

 same phrenomena take place. 



Thus at certain epochs, in certain organs, the plant turns 

 into an animal; it becomes like it an apparatus of combus- 

 tion; it burns carbon and hydrogen; it gives out heat. 



But at these same periods, it destroys in abundance the 

 saccharine matters which it had slowly accumulated and 

 stored up. Sugar, or starch turned into sugar, are then the 

 primary substances by means of which plants develop heat as 

 required for the accomplishment of some of their functions. 



And if we remark with what instinct animals, and men too, 

 choose for their food just that part of the vegetable in which 

 it has accumulated the sugar and starch which serve it to 

 develop heat, is it not probable, that, in the animal ceconomy, 

 sugar and starch are also destined to act the same part, that 

 is to say, to be burned for the purpose of developing the heat 

 which accompanies the phaenomenon of respiration ? 



To sum up, as long as the vegetable preserves its most ha* 

 bitual character, it draws from the sun heat, light, and che- 

 mical rays. From the air it receives carbon, from water it 

 takes hydrogen, azote from the oxide of ammonium, and dif- 

 ferent salts from the earth. With these mineral or elementary 

 substances, it composes the organized substances which accu- 

 mulate in its tissues. 



