60 Proceedings of Philosophical Societies. [July, 



tises, the object of the first of which is to explain what natural 

 philosophy means. The author here endeavours to justify at 

 large the definition he has made use of in other writings, accord- 

 ing to Avhich natural philosophy is the science of the general 

 laws of nature ; yet he will not confine this science within the 

 narrow circuit which several German authors have drawn by the 

 name of algemeine naturlehre (physica generalis) ; but admits 

 into it the doctrine of electricity, magnetism, light, heat, and 

 chemical affinities, as they are all immediate consequences of 

 the general powers of nature. He is of opinion that even the 

 qualities of the different matters from this more extended point 

 of view ought to be regarded as peculiar effects of the general 

 powers of nature, which in every one of them appear in a parti- 

 cular development and strength. 



The author having already formerly endeavoured in several 

 writings to prove that the electrical powers are the same with 

 the chemical, only in a more free condition, and having at the 

 same time alleged that magnetism, light, and heat, are effects 

 of the very same powers, all in natural philosophy that does not 

 treat of motion unite to form a coherent doctrine of powers or 

 chemistry in the most extensive sense of the word. The 

 first of these parts of natural philosophy (in this sense of the 

 word) comprehends the external changes ; the second the 

 internal. 



It is evident that no more can be added to these two parts, 

 except the doctrine of the union of powers and motion ; for 

 instance, in light and the radiant heat ; but whether this doctrine 

 is to be separated from the rest as an independent chapter, or 

 is to be comprised in the doctrine of powers, cannot perhaps be 

 determined before natural philosophy has obtained a far greater 

 perfection. 



The author intends, as soon as possible, to give the continua- 

 tion of these inquiries. His design is thereby to introduce and 

 occasion an inquiry concerning this subject among natural philoso- 

 phers, and thinks it very useful to the science if they could agree 

 upon the form and construction of a system in the science ; and 

 all the learned in the said science would then work jointly to 

 complete it ; and thus in time a work would be produced con- 

 taining a complete picture of the science in the age given. 

 The author does not of course mean that all systematical books 

 ought to be composed after the very same plan, which indeed 

 might be altered according to the different aim of the author, 

 but in such systems as aimed at nothing else but evidently to 

 explain the science, he thinks that the same order and way of 

 proceeding ought always to be followed, when the learned had 

 previously agreed to declare it to be the proper one. But that 

 such a concord respecting a theory of systematical books should 

 be obtained, he thinks, to be as possible as the concord subsist- 

 ing among the philosophers respecting so many other theories. 

 Although we are already possessed of such proofs of the com- 



