lum*, and on wiiich is founded the wholfe »y8tem of nataml 

 philasophy. 

 »nd «]ectrical In the second place th«l force of electrical attraction is, 

 attraction is catetis paributy jJroportionate to the extent of the surfaces 

 the surface, of the attracting bodies; gravitation, on the contrary, 10 

 f^uatwm 10 proportionate to the quantity of matter reciprocally at- 

 tracting, and has no dependance on the extent of surface. 

 This essential difference between the two powers is pecu- 

 liarly stijikin^'— A bit of gold leaf, of tin foil, or of sheet 

 lead, will acquire a rapid motion through the air, when 

 acted ion by ah excited electric, which would not sensibly 

 affect an e^ual qu:uitity of either of these metals in a 

 globular form ; and yfet the gold leaf, the tin foil, or the 

 sheet lea4 trill have to ov«»cotne considerably tnorc resist- 

 ance In passing through the air, than will a globule of gold, 

 of till, or of lead. On the contrary a given quantity of 

 gold, of tin, or of lead, will gravitate more rapidly, in the 

 tnediura of our atmosphere, when in a globular form, 

 than when beaten out into gold leaf, tin foil, or sheet lead ; 

 not that the force of attraction is diminished by the exten- 

 sion of the metals, but because in an extended form they 

 hivt to overcome a greater degree of resistance from the 

 clastic medium, through which they are to pass. .. 



Thus, I conceive, it is demonstratively proved, thitt the 

 attraction c^f gravitation is not identical with electrical at- 

 tKaction. Qur views, therefore, of the phenomena of na^ 

 ture would not be reiwlered more simple by admitting, th^t 

 * chemical attraction and electrical attraction are identical ; 



tA this woukl draw a line of distinction between the prin- 

 ciple of chemical attraction, and the principle of gravita- 

 tion. Every one must determine for himself whether the 

 hypothesis, proposed by Mr. Davy, be supported by argu- 

 ments more plausible, than those, which can be adduced in 

 favour of the identity of chemical attraction, and the attrac- 

 tion of gravitation. 

 Attraction Pliilosophei's of the present day most commonly speak of 



«o«*idered as attraction as an ultimate property of matter ; not that they 



• Newlont PhJi. Miat» Frlocip* Math. L. Ill, Prop. VI, Theor. VI. 



y0 ■ conceive 



