Index. 293 



lated, 82 winds, 84 clouds, rain, &c. 92 thunder 

 and lightning, 118 comparative density of the atmo- 

 sphere, ii. 1 1. See al*o Pneumatics. 



Attraction, lecture on, i. 10 experiment illustrating, 12 

 great law concerning, 15. See Chemical, Cohesion, 

 Elective, Electrical, Gravity, and Magnetic. 



Attractions, analogy between magnetic and electric, i. 34. 



Axis of the earth, inclination of the, to the plane of the 

 ecliptic ; uses of this, ii. 1, 2. 



Axle, principle of the, i. 238. 



Azimuth, meaning of the term, i. 267. 



Azote. See Nitrogen. 



B. 



Balsams, nature of, ii. 220, 221. 



Banks of rivers, &c. why blow up, i. 42. 



Barometer, principle of the, i. 67. 



Battery, electric, i. 108 galvanic, 125. 



Barytes, account of this earth, ii. 1Q5, 196. 



Bellows, principle of the hydrostatic, i. 41. 



Bells, experiment with electrical, i. 112. 



Bitumen always discernible in waters, ii. 267. 



Boiling point differs widely in different bodies, and is re- 

 markably influenced by mechanical pressure, ii. 76 

 degree at which water boils in vacuo, 77 cause why 

 water does not become hotter by being boiled long, 73 

 curious result of an experiment to boil ether in vacuo, 



79, 80- 



Bolognian phosphoru?, how discovered, i. 138. 

 Boracic acid, nature and properties of, ii. 159, *60. 

 Breezes, land and sea, in the tropical climates accounted 



for, i. 85, 80". 

 Burning glas-es, experiments with, i. 140. ii. 65 curious 



experiment with concave mirrors used as, i. 176. 

 Burning glass, rays of light how collected in the focus of a, 



i. 137 experiment with on transparent and opaque 



bodies, ii. 05. 



C. 



Calcination of metals, ii. 226, 227. 



Calendar, reformation of the, under pope Gregory, ii. 16. 



