430 On Chemical Philosophy. 



these circumstances we have emunerated, on its being more f>t* 

 less occupied or free to act ; as water already saturated with one 

 salt in solution, is less able to dissolve a salt of another kind j 

 in fact, these observations are equally true of this power in all 

 cases. For instanccj a man has power to Walk, whether he move 

 or not; but if he carries weight, he can neither walk at the same 

 rate, nor for the same time, nor to the same distance : the power 

 in the abstract is the same, but part of it is occupied in support 

 of this burthen. We express all this in common conversation, 

 when we say, "of what use are strength or talents unless they 

 are exerted ? and that they are best shown by undivide'd exer- 

 tion." This is true in physiology. — Let the nervous energy be 

 occupied too much in one way, and the functions of some other, 

 if not of every other, part arc either diminished or impaired. 



Thus its apparent energies and intensity are different, not 

 merely from its being imparted and received in greater or less 

 quantity, and with a greater or less degree of rapidity, and of 

 purity or separated form ; but also as it is in a more or less con- 

 centrated or diffused manner. All these and many other circum- 

 stances attending its action are so infinitely varied in the degree 

 and complexity of their combination, and depend on such an 

 infinite number of causes and circtimstances, and all these in 

 themselves so delicate and interwoven with each other, — that it 

 is impossible, and if it were possible would be less profitable, I 

 think, for us to trace them through all their diversity of form 

 and appearance, than the task we have assigned to ourselves, 

 though we intend to support these general principles by descend- 

 ing to the minute detail of facts, which facts in -diversity of form 

 and appearance are infinite; and hence one of the in some 

 measure appropriate and descriptive names applied to it, in the 

 mythology of the ancients, was Proteus. Their mythology 

 too, let me here observe, originated in either unnecessarily mul- 

 tiplying the causes of things, or in that of improperly applying 

 names, descriptive of partial effects and peculiarities. 



I say, all these and many other circumstances, though they 

 have not hitherto been noticed, not only agree with the facts 

 and phaenomena of nature, but point out in the most beautiful 

 manner the causes which vary the effects and Jippearances of one 

 GRAND AGENT in creation ; which point out why it assumes these 

 different forms and produces these different effects ; — why che- 

 mical attraction and the attraction of gravitation aie different J 

 that the one is the particular, and the other the general effects 

 of the same power ; — that t!ie one is the local and concentrated, 

 and the other diffused and aggregate effects of its operation ; — • 

 why in its concentrated actions the heat is sometimes without 

 light j why they generally appear together ; why it is electri- 

 city 



