from Water exposed to Light. 213 



Upon the 14th, a few air-bubbles only were furnished ; 

 but, notwithstanding these unfavourable appearances, I 

 still continued the experiment, and my patience was amply 

 rewarded ; for the next day, the 15th, the sun being very 

 powerful, and the weather very hot, the water, changing 

 suddenly to a greenish colour, began all at once to give 

 good air in great abundance. In the course of the day, 

 ^°tVo" cubic inches were produced, which, proved with 

 nitrous air, gave \ a -\- i^n ^=^ I-43j or 257, 



June 16th, a very warm, clear day. The globe, ex- 

 posed in the sun from 8 o'clock in the morning till 5 

 o'clock in the afternoon, furnished 141V0" cubic inches of 

 air, which, proved with nitrous air, gave i ^ -|- 3 ;z = i .34, 

 or 266. 



June 17th, cloudy, with intervals of sunshine. The 

 globe, with about four hours sun, gave 7iVo cubic 

 inches of air, of a very eminent quality, vi'z. 1 a -\- /\.n 

 = 1.40, or 360. 



The water having by degrees lost its transparency, and 

 having acquired a deep green colour, it broke up this 

 day, and deposited a green sediment ; after which it re- 

 covered its transparency, and became almost colourless. 

 It continued, notwithstanding, to furnish air in consider- 

 able quantities. 



June 1 8th, being exposed in the sun's rays from 8 

 o'clock in the morning till 2 o'clock in the afternoon, 

 (when the heavens became overcast,) the globe yielded 

 ^iVo cubic inches of air, which, proved with nitrous air, 

 gave I a-\- ^n = 1.44, or 356. 



June the 19th and 20th. These two days the globe 

 furnished no more than 3yVq cubic inches of air, which, 

 proved with nitrous air, gave i a -\- j n = 1.06, or 294 ; 

 after which it ceased totally to furnish air, and the colour 



