1 20 On Chemical Philosophy. 



secondary causes altogether unconnected with that power. Be- 

 sides, in either Ught, the present state of science, and our ac- 

 quaintance with these agencies in particular, render it necessary 

 to give them a separate and distinct consideration ; and in fact, 

 the consideration of these wonderful phaenometia, — of electricity, 

 — of galvanism,— of magnetism, — of caloric, and of light, are 

 incomparably the most interesting, entertaining and brilliant 

 parts of the subject. 



I need not defend the propriety of this generic term, which 

 I have for the present adopted* : — the reader will be convinced 

 it is the best I could have chosen, in connexion with attraction j 

 the one caimot be altered without changing the other. Nor is 

 it necessary to halt, in order to point out the defective and ill- 

 assorted terms of imponderable substances, or immaterial sub- 

 stances, or impalpable substances, or ethereal matter, or radiant 

 matter, and a variety of other terms which dissatisfaction and 

 difficulty have given them. 



Innutneralde facts prove that these Attractive Agencies are 

 connected with attraction in the operations of nature, and so 

 closely that they cannot be discerned to precede or follow each 

 other J and I deny (and shall afterwards prove) that they can be 

 procured separately and isolated. It is from a complete con- 

 viction of these facts, that I shall, to avoid repetition, and when 

 speaking in a more general manner, class them together under 

 the terms, The grand agent, — Attractive agencies, — The princi- 

 ple or poiuer of' nature, &c. 



In my opinion, there are no changes in nature or art, no action, 

 movement or operation, however slight or however produced, in 

 which they may not be detected, in whatever light the reader 

 may view them. Whether as primary effects of distinct powers, 

 or as agents, obeying and observing the laws of that power on 

 which every thing depends, the name Attractive Agencies 

 will apply. By considerations which will be gradually unfolded 

 as I proceed in these Essays (which I hope to do monthly), I have 

 been led to a decided conviction — a conviction so strong that I 

 know not what further proof could increase it — that electricitv, 

 caloric and light are merely effects and phaenomena arising from 

 the nature of the substances on which, and the circumstances in 

 which, the properties and energetic actions of one power are ex- 

 erted and ajjplied ; — that changes and phaenomena differ not in 

 kind, but in degree ; not in the power producing them, but in 

 the nature and circumstances of its actions : — But of this in its 

 proper place. 



In every system of chemistry, the intimate connexion of ca- 



* See Appendix to Essay I. above, from whence it will be evident that 

 1 conceive this term objectioniible, &c. 



loric 



