58 The Chemical Statics of Organised Beings. 



by oxidation (en se brulent) at the moment of germination ; waxes 

 with which leaves and fruits are covered so as to become imper- 

 meable to water. 



But all these uses constitute some accidents only in the life of 

 plants ; thus the hydrogenated products are much less necessary, 

 much less common, in the vegetable kingdom, than the neutral 

 products formed of carbon and water. 



Azote. — During its life, every plant fixes azote, whether it 

 borrows the azote from the atmosphere, or takes it from the ma- 

 nure. In either case it is probable that the azote enters the plant, 

 and acts its part there only under the form of ammonia or of 

 nitric acid. 



M. Boussingault's experiments have proved that certain plants, 

 such as Jerusalem artichokes, borrow a great quantity of azote 

 from the air; that others, such as wheat, are, on the contrary, 

 obliged to derive all theirs from manure : a valuable distinction 

 for agriculture; for it is evident that all cultivation should begin 

 by producing vegetables which assimilate azote from air, to rear 

 by their aid the cattle which will furnish manure, and employ 

 this latter for the cultivation of certain plants which can take 

 azote from the manures only. 



One of the most interesting problems of agriculture consists, 

 then, in the art of procuring azote at a cheap rate. As for 

 carbon, no trouble need be taken about it ; nature has provided 

 for it ; the air and rain water suffice for it : but the azote of the 

 air, that which the water dissolves and brings with it, the am- 

 moniacal salts which rain water itself contains, are not always 

 sufficient. With regard to most plants the cultivation of which 

 is important, their roots should also be surrounded with azotated 

 manure, a permanent source of ammonia or of nitric acid, which 

 the plant appropriates as they are produced. This, as we know, 

 is one of the great expenses of agriculture, one of its great ob- 

 stacles, for it possesses only the manure which is of its own pro- 

 duction. But chemistry is so far advanced in this respect, that 

 the problem of the production of a purely chemical azotated 

 manure cannot be long in being resolved. 



M. Schattenman, the skilful director of the manufactories of 

 Bouxvilliers in Alsace, M. Boussingault, and M. Liebig have 

 turned their attention to the functions of ammonia in azotated 

 manures. Recent trials show that the nitric acid of the nitrates 

 also merit particular attention. 



But for what purpose is this azote, of which plants seem to 

 have such an imperious want ? M. Payen's researches partly 

 teach us ; for they have proved that all the organs of the plant, 

 without exception, begin by being formed of an azotated matter 

 analogous to fibrine, with which at a later period are associated 

 the cellular tissue, the ligneous tissue, and the amylaceous tissue 



