APPENDIX. NOTES. 409 



I observed, on a former occasion, that the clouds are in- 

 stinct with all those principles by which God acts upon the 

 earth^ They are not only pregnant with light, but also 

 when evaporation takes place, by which clouds are formed, 

 water carries off with it in combination the matter of heat. 

 In thunder storms, combustion may be said to take place as 

 well as the evolution of light the electric fluid indeed 

 seems peculiarly connected with the clouds : it has been 

 observed also, that a heavy cloud passing over with a hasty 

 fall of snow or hail is often attended by a hasty and violent 

 gust of wind, which subsides into a calm with the departure 

 of the cloud ; till another coming in the same direction 

 brings with it a fresh blast. 2 Light, however, is most con- 

 spicuously connected with water and the clouds ; we are 

 told that heat without it cannot produce air from water, 

 but as soon as light acts upon it bubbles arise. 3 In thun- 

 derstorms, the lightning enlightens the world ; but the 

 principal phenomenon in which light and water appear to 

 be united, takes place when the rainbow is exhibited, which 

 may be called a personification of light, otherwise itself in- 

 visible, though it reveals to us the whole creation of God, 

 of which without this blessed medium we should neither 

 know the forms, nor the colours, nor the motions. 



/ have set my bow in the cloudy saith God to Noah, and 

 it shall come to pass, when I bring a cloud over the earth, 

 that the bow shall be seen in the cloud, and I will remember 

 my covenant which is between you and me, and every living 

 creature of all flesh ; and the waters shall no more become a 

 flood to destroy all Jlesh.* The cloud here mentioned is 

 evidently a rain-cloud, 5 discharging its contents ; and the 



1 Introd. xciii. 



2 Adams Lect. on Nat. Philos. iv. 533. 



3 Ibid. i. 439. * Gen. ix. 1315. 

 5 Nimbus. Forst. 



