GENERAL INDEX. 



The references are given to the treatise, or treatises, in which the article is to be found. Of the con- 

 tractions, POP. IVT. stands for Popular Introductions; NE\V. OPT. for Newton's Optics; OPT. 

 INST. for Optical Instruments; THERM, for Thermometer and Pyrometer ; ELECT, for Electricity; 

 GALV. for Galvanism; MAGN. for Magnetism; and ELECT. -MAGN. for Electro-Magnetism. 



ABERIIATION ; spherical account and cause of . . . NEW. OPT. 



effects of in lenses .... 



effects of in mirrors . . . OPT. INT. 



minimum of,' in lenses . . . 



. . . in inverse ratio of the magnifying 



. . comparative in glass, sapphire, and 



diamond ......... 



Academy del Cimento, their improvements on the thermometer THERM. 



French, their attempted improvements on . . 



Account, Oersted's, experiments on electro-magnetism . ELECT. MAG. 



Accumulated electricity, experiments on the motion of . ELECT. 



. . . . by induction .... . 



Accumulation of water in hills, cause and consequence of . POP. INT. 



Achartfs pyrometer, description of .... THERM. 



Achromatic telescopes, principles and description of . . OPT. INST. 



the largest ever known*, described . 



eye-pieces for astronomical telescopes . . . 



opera glasses, construction of . . 



Acids decomposed by the voltaic pile .... GALV. 



Action, chemical, connection between, and electricity . ELECT. 



mutual, of two magnets, experiments on . MAGN. . 



and reaction, their equality an established law of 



nature ........ 



.. electro-magnetic, fundamental law of . . . ELECT. MAGN. 

 Action and Reaction, that their equality is one of the laws 



of motion, illustrated POP. INT. 



of a bird in flying described .... 



of the oar in raising a boat described . . . 



of the fly-wheel explained ..... 



of gravity, and the pressure of fluids, explained . 



of sonorous bodies illustrated . . . . 



Actions, electric and magnetic, emanate from a common 

 source ......... 



mutual, of electric current, concerning generally . 

 particularly, described. 



(See Electric Currents.} 



./EPINUS, his amendments of Franklin's theory of electricity 

 his theory of magnetism ..... 



corrections of his theory of magnetism . . 



his method of making artificial magnets . . 



Aerial vibrations, their reflexions the cause of echoes . POP. INT. 



Age, the decay of sight consequent upon, how remedied . 



. . its effect upon thermometers .... TKERM. 



Air, in what it differs from liquids ..... POP, INT. 



. . atmospheric, its mechanical properties . . . 



. . elasticity of, experiments to prove .... 



. . its enormous pressure on the human body . . 



. . its resistance to falling bodies 



ELECT. MAGN. 



ELECT. 

 MAGN. 



33 



12 

 35 

 . 36 

 47,48 

 . 72 

 97 



. 12 

 1 



. 7 



65 



65 



7 



