from Water exposed to Light. 227 



air, of 307 degrees (or i a -(- 4 n = T -93)> was f" ur ~ 

 nished ; after which an end was put to the experiment. 



Total quantity of air produced, 3xV 9 o cubic inches ; 

 mean quality, 291 degrees, or i a -|- j n 1.09. 



Finding that leaves which were dead, or in which all the 

 powers of vegetation were evidently destroyed, continued, 

 notwithstanding, to separate air from water, and that in 

 so great abundance, I was desirous of seeing the effect 

 of exposing fresh, healthy leaves in water which I knew 

 to be previously saturated with, and disposed to yield, 

 dephlogisticated air. I conceived that if the plants ex- 

 posed in water actually imbibed fixed or phlogisticated 

 air as food, and after digesting it, " discharged the deph- 

 logisticated air as an excrement " ; in that case, as there 

 is no instance of any plant or animal being able to 

 nourish itself with its own excrement, the leaves exposed 

 in water saturated with dephlogisticated air, instead of 

 imbibing and elaborating it, would immediately die. 



The experiments which I made to ascertain this fact, and 

 which, without any comment, I shall submit to the con- 

 sideration of the reader, were as follows. 



Experiment No. 30. 



Having provided a quantity of water, which, by being 

 exposed with a few green leaves in the sun, had acquired 

 a greenish cast, and which I found was disposed to yield 

 dephlogisticated air in great abundance, I filled a globe, 

 containing 46 cubic inches, with this water, and putting 

 to it two healthy peach-leaves, exposed the globe in the 

 sun upon the yth of September, from 1 1 o'clock in the 

 morning till 2 o'clock in the afternoon (3 hours), when 

 -jpo- of a cubic inch of air was produced, which, proved 

 with nitrous air, gave i a -j- 3 n = 1.52, or 248 degrees. 



