from Water exposed to Light. 205 



they detached themselves to rise to the surface of the 

 water. 



Experiment No. 9. 



The globe No. 4, with cotton-wool, furnished a con- 

 siderable quantity of air, which appeared to -be better 

 than that furnished by any of the five other globes. 

 Proved with nitrous air, it turned out i a -\- 3 n = 1.07, 

 or 293, and, what was particular, the water did not appear 

 to have altered its colour in the least, or to have lost any- 

 thing of its transparency. 



Experiment No. 10. 



The globe No. 5, with ravelings of linen, was very 

 tardy in furnishing air, and produced but a small quan- 

 tity ; at the end of a fortnight, however, I collected 

 about 2 cubic inches, which, proved with nitrous air, 

 gave i a -\- 3 = i-5ij or 249. 



The air appeared to have very little disposition to 

 fix itself to the surface of this substance. It was very 



seldom that there were air-bubbles enough attracted to 



o 



it to cause it to rise to the surface of the water, and the 

 few bubbles which occasionally made their appearance 

 very soon disappeared upon the diminution of the light 

 and heat of the sun. In short, it appeared that there 

 is but a very feeble attraction between this substance 

 and the particles of air, at least when they are dissolved 

 in water. Whether this arises from the superior affinity 

 of the substance to water or not, I will not pretend to 

 decide ; but it appears to be probable, as there is so 

 strong an attraction between water and linen, or flax, 

 which is apparent from the avidity with which a piece 

 of dry linen drinks up that fluid, and becomes wet even 

 to a considerable distance when one end of it only is 

 placed in water. 



