VOL. LXXII.] PHILOSOPHICAL TRANSACTIONS. 321 



yielded a good quantity of air, which was so far dephlogisticated as to be able 

 to kindle a wax taper just extinguished. After the 10th day the vegetable began 

 to die. 



The vegetable very soon threw up air bubbles; because this water, being in its 

 natural state, and thus saturated with air, could not absorb much of the air issu- 

 ing from the vegetable, which air must, of course, soon rise up in visible bubbles. 

 A great deal more air was collected than in exper. 1, because less of the air is- 

 suing from the plant was absorbed by this water than in exper. 1. The air ob- 

 tained was not so good as that obtained in exper. 1 ; because the air in this ex- 

 periment was somewhat infected by the air issuing from the water, which was 

 but common air. The water sparkled when the vessel was shook, because this 

 water, though it had probably lost some of its own air, yet had assumed a 

 great deal of air from the plant, which air disengages itself from the water very 

 easily, just as fixed air does; the more so when the water is moved. This water 

 yielded, by heat, true dephlogistioated air; whereas the same water, when it has not 

 been exposed to the action of a vegetable, yields by heat nothing but common 

 air. The reason of it is, that the air elaborated by the plant, with which this 

 water was saturated, was real dephlogisticated air. The vegetable at last lan- 

 guished and began to die, because the water was impregnated with dephlogisti- 

 cated air, which being an excrement of the plant is hurtful to its constitution. 

 Besides, this water had at last lost the most part of, or perhaps all, its own stock 

 of common air; and with this all the nutritive nourishing and phlogistic particles, 

 which were taken in by the plant, and was therefore become less fit to keep up 

 vegetable life. 



All these experiments were repeated frequently, and always with the same 

 o-eneral results. Dr. I. therefore thinks the abovementioned facts will be con- 

 sidered as quite sufficient to put his doctrine out of all further question. And 

 after having demonstrated, as he thinks, in the clearest manner, that vegetables 

 diffuse through our atmosphere, in the sun-shine, a continual shower of this 

 beneficial, this truly vital air; and that plants immersed in water, far from 

 robbing it of all air, impregnate it fully with a better and more salubrious air ; 

 let us not pass, he says, so wonderful, and hitherto not even so much as sus- 

 pected, an operation of nature, without admiring the designs of that infinite 

 wisdom, who has employed such hidden, such wonderful, and at the same time 

 such beneficial means to preserve from destruction the living beings which in- 

 habit our earth ; and let us consider, whether it would not be worth while to 

 attempt drawing some benefit from this new discovery, by making use of vessels 

 of water, in which some leaves of vegetables have been exposed in the sun-shine ; 

 by placing such vessels in our rooms ; by stirring the water ; by sprinkling with 

 it our floors, instead of using for this purpose common water ; by placing within 



vol. xv. T T 



