ATMOSPHERIC AIR AS THE FOOD OF PLANTS. 



2d 



constantly renewed, and carbonic acid was introduced ia 

 proper quantity. The experiments were conducted on a 

 larger scale than those of Boussingault, and their result 

 was uniformly the reverse. Ville indeed thought to have 

 established that vegetation feeds on the free nitrogen of 

 the air. To the conclusions to which Boussingault drew 

 from the trials made in the manner already described, Ville 

 objected that the limited amount of air contained in the 

 glass globes was insufficient for the needs of vegetation ; 

 that plants, in f ict, could not attain a normal development 

 under the conditions of Boussingault's experiments. — 

 (Ville, Recherches sur la Vegetation , pp. 29-58, and 53-98.) 



Boussingault's Later Experiments. — The latter there- 

 upon instituted a new^ series of trials in 1854, in which 

 he proved that the plants he had previously experimented 

 upon attain their full development in a confined atmosphere 

 under the circumstances of his first experiments, provided 

 they are supplied with some assimilable compound of ni- 

 trogen. He also conducted seven new experiments in an 

 ajjparatus which allowed the air to be constantly renewed, 

 and in every instance confirmed his former results. — 

 {Agronomic^ Chimie Agrhole et Physiologie^ Tome I, 

 pp. 65-114.) 



The details of these experiments are given in the follow- 

 ing Table. The weights are expressed in grams. 



Kind of Plant. 



Duration 



of 



Expenment. 









Lupin 

 Bean . 

 Bean . 

 Bean . 

 Bean. 

 Lupin 



Cress. 



10 weeks 

 10 " 



12 " 

 14 " 



13 " 

 i 9 " 



I as manure 

 1 10 weeks 

 I as manure 



0.337 

 0.720 

 0.718 

 0.755 

 1.510 

 0.310 

 Q.m) 

 0.100 



2.140 0.0190 0.011S7 —0.0009 

 2 . 000 . 0322 . 0325 +0 . 0003 

 2.^7 0.0;»5 0.0:M1:+0 0006 

 2.240,0.0339 0.0329 -0.0010 

 5.150 0.0676 0.0606 —0.0010 

 1.730 0.0355 0.0324'— 0021 



I I I 



0.533 0.0046 0.0052 4-0.0006 



^Mf» .4.780 



16.6410. 2269 O.JJ340I-0.0035 



