On Chemical Philosophy. 429 



cr less quantity ; and to conduct or receive and impart it with 

 more or less facility, and are surrounded by other substances of 

 a similar or different nature; — that then these differences in the 

 circumstances and in the kinds of matter must by every altera- 

 tion in these circumstances, or in the position of the substances, 

 or in the quantity of this power, he deranged in a greater or less 

 degree in its " due and relative diffusion," and of course call this 

 GRAND LAW of nature into actioti, to restore " this due and re- 

 lative share ?" and hence it is imparted and received from one to 

 another, in greater or less quantity; with more or less intensity, 

 and in a certain and determinate direction. 



Its quantity and intensity will depend on the nature and ex- 

 tent of the change which variations in the quantity of this power, 

 in the arrangement of the substances and in the circumstances, 

 produce on dirferent species of matter ; for it is given out or de- 

 manded (and of course received} in proportion to the extent of 

 the change produced. 



The imperfect and erroneous views on the doctrine of heat 

 appear to me to have arisen from overlooking the fact, — that 

 this power when demanded flows in from all points to supply 

 this demand, (This explains the operation of freezing mixtures, 

 explosion^&c.) wiih as much facility and rapidity as it flows out 

 when in excess, or when separated from substances it held in 

 solution, and whatever receives or demands it on some point in 

 sufficient quantities produces heat or flame. The intensity of 

 this quantity again depends on its being given out or received 

 on some point of concentration, or in a more or less diifused 

 manner, or in a greater or less degree of purity or separate and 

 unmixed state, which degree of purity or separate and unmixed 

 form is in proportion as substances are more or less soluble in it, 

 and the time it has to effect their dissolution ; and of course in 

 proportion to the quantity it holds in solution, it is rendered more 

 or less attenuated or condensed : and hence we find it passing 

 through substances with more or less facility, or with a greater 

 or less degree of rapidity, and in proportion to this resistance of 

 its passage through them, has more or less time to produce ef- 

 fects upon them : and besides, this detention giving it more or 

 less time to produce these effects, in some instances they tend 

 to direct and fix its action, from the disposition these substances 

 held in solution have to combine with others. At other times, 

 from the same cause, but with different substances, it becomes 

 more or less energetic and effectual in its actions, in proportion 

 as it is more or less free or unoccupied to act; so that though 

 the energies and properties of this power appear so various, they 

 arc in reality always the same. 

 Its apparent energies, however, are widely different, owing to 



these 



