480 Rev. W. V, Harcourt on Lord Brougham's statements 



forces centrifugal, or centripetal, varying with aggregation 

 and distance. Of such particles, grouped in various modes 

 and degrees of condensation, and variously moulded by the 

 hand of the Creator, he thought all material things might be 

 imagined to consist, by such, both the stability of nature and 

 the conservation of motion might be maintained, and from 

 such, all the great classes of phaenomena might be derived. 



The general name which he gave to the simplest of these 

 particles was (Ether — a term which he used for the substance 

 of one, or more, highly subtle and elastic fluids, capable of 

 being combined and condensed, and taking, in different states 

 of condensation, the form of light and ordinary matter. 



His aether was not a mathematical or mechanical abstrac- 

 tion, but a material substance, of the actual existence of which, 

 certain otherwise uninterpretable phaenomena, especially of 

 light, heat, and electricity, had convinced him, and which he 

 conceived of, as being " much of the same constitution with air, 

 but far rarer, subtler, and more elastic" — " not of one uniform 

 matter, but composed, partly of the main phlegmatic body of 

 aether, partly of other various aetherial spirits, much after the 

 manner that air is compounded of the phlegmatic body of air 

 intermixt with various vapours and exhalations," — one of these 

 spirits being the electric, another the magnetic, a third the 

 gravitating principle. The latter he figured to himself as " not 

 of the main body of phlegmatic aether, but of something very 

 thinly and subtilely diffused through it (perhaps of an unc- 

 tuous, gummy, tenacious or springy nature*), and bearing 

 much the same relation to aether which the vital aerial spirit, 

 requisite for the conservation of flame and vital motions, does 

 to air\." 



This was the first speculation of Newton respecting " the 

 cause of the gravitating attraction of the earth." " For if 

 such an aetherial spirit," he adds, " may be condensed in fer- 

 menting or burning bodies, or otherwise coagulated in the 

 pores of the earth and water into some kind of humid active 

 matter, for the common uses of nature (adhering to the sides 

 of those pores after the manner that vapours condense on the 

 side of a vessel), the vast body of the earth, which may be every 

 where to the very centre in perpetual working, may continually 

 condense so much of this spirit as to cause it from above to 

 descend with great celerity for a supply : in which descent it 



* Such expressions as these, used only in the earliest of Newton's spe- 

 culations, appear to be in the style of the Epicurean school; but his mean- 

 ing, as is evident from the variety of the terms which he uses, was only to 

 describe in popular language, attractive and repulsive force. 



t Registry Book of the Royal Society, vol. v. from 1675 to 1679, p. 67. 



