214 KECENT RESEARCHES ON THE RESPIRATION OF PLANTS. 



dons to come into still closer contact with the air whicli sur- 

 rovinds them. 



To measure the activity of the respiration of young plants, 

 some seeds were sown, from the 12th to the 16th of April, in very 

 fine siliceous sand moistened with rain-water, and placed in glass 

 capsules. After germination the episperms were carefully re- 

 moved, and the glasses mth the vegetating plants were placed 

 under a bell-glass as before. After having carefully measured 

 the diminution of the volume of air, the young plants were taken 

 with tlieir radicles, washed in a little stream of water to get rid 

 of the sand attached to them, wiped, weighed, then dried at a 

 temperature of 110° C, and weiglied again. The following 

 table shows the conditions under which the experiments were 

 made, and the results obtained from them : — 



Comparing the volume of acid produced with that of the plants 

 containing their water of vegetation, the proportion will be found 

 to be that of 6 to 1, or thereabouts; but if the comparison is 

 made with the weight of the organic matter dried at 110° C, it 

 will be seen that in reality they consume, in the same space of 

 time and in Ihe same conditions, a much larger quantity of 

 carbon than is consumed by the buds ; and this might have been 

 expected, inasmuch as the seeds, at an early stage of germination, 

 part with tlieir episperm, which is very poor in animal matters, 

 and their living azotized substances, which form the seat of the 

 respiratory action, are thus relatively increased. 



In a former paper {Atm. des Sci. Nat., 1851) I had collected 

 some proofs which are increased by the new facts just related ; for 

 now as then it may be seen, on consulting the analytical results 

 given hereafter, that the organic azote contained in the buds, the 

 young plants, and the leaves is abundant in proportion as tlieir 



