Respiration of Plants. 129 



ill moistened paper between two plates. Next day, during 

 summer, they had all completely germinated, and the radicles 

 had projected some fom" or five lines. 



As to the production of the gas, we shall observe that that 

 which was disengaged, traversed the water, and passed through 

 the tube into the receiver, was only the sign of the function ; 

 and nothing more than the overplus of that which was dis- 

 solved in the water at the moment it was formed ; it must also 

 have been in very small quantity. The proportion of air 

 which had traversed the water without being dissolved by it, 

 amounted to between 20 and 40 millilitres ; but that which 

 was dissolved in the water, and which was disengaged by boil- 

 ing, was very considerable, and might well, as it did, surprise 

 us. 



The whole interest of the experiment here depends upon 

 the quantity of the air naturally contained in the water, com- 

 pared with that which had been produced by the seed. Ac- 

 cordingly, we made many experiments to ascertain the pro- 

 portion of air contained in the water of the well which we 

 used ; and we found that the water in our bottles before the 

 experiments, as the mean of our observations, contained 7.5 

 centilitres of air, and after the experiment 55.5 centilitres, 

 in an experiment of five days' continuance. Hence, after sub- 

 tracting the air naturally contained in the water, we find 47.7 

 centilitres of gas, produced solely by the action of the water and 

 the beans. The result of another expei'iment, which lasted for 

 six days, after making the same subtraction, was 50.5 centi- 

 litres of gas, produced above the quantity of air naturally dis- 

 solved in the water of the bottle. There was, therefore, dis- 

 engaged by the sole action of the seeds and the water, after 

 subtracting the au' which the latter contained, more than half 

 a pint of gas ; a very remarkable effect, and which, Avhen seen 

 on so great a scale, leaves not the slightest doubt as to the 

 action of water in the respiration of beans, abstraction being 

 made for the air contained in the liquid. 



Our next object was to ascertain what information analy- 

 sis would give us respecting the nature of the gas supplied 

 by the seeds. And first, there was an enormous proportion 



VOL. XXVII. NO. Mil.- — JCLV 1839. J 



