HISTORY OF THE ATOMIC THEORY. 24 1 



in our elements; at least, he expressly reserved this point. 

 What he speaks of is simply the ultimate particle that seems 

 to act in our chemical processes. 



Dalton used atom and particle. Many have objected to 

 both, but they are words which really involve less theory, and 

 are more generally applicable than any yet obtedned, except, 

 perhaps, combining proportion, which is too long. Equivalent, 

 Wollaston's word, is itself too long, limited in its meaning at 

 best, and at times either meaningless or incorrect. Whenever 

 we conceive of combining proportion, we reduce the quantity 

 to the smallest conceivable, every portion becomes a unit, 

 and each unit is undivided ; it is a particle for the moment, 

 and an atom as far as the effect we study is concerned. 

 Having, after much labour, attained this mode of thinking, 

 we can now scarcely think of compounds otherwise, nor 

 indeed has any other method suggested itself as better, al- 

 though investigation is promising advance in our knowledge, 

 and will probably some day astound us by its results. 



The consequences of Dalton's laws gradually shewed them- 

 selves to be, that there was now one great law or theory in 

 chemistry, so that it was for the first time fit to be called a 

 science. Heretofore it was a series of separate facts, and even 

 now we may say that it is more a branch of natural history 

 than of exact science, but as a science it is preserved by this fun- 

 damental law and its branches, and by this only. It is stretch- 

 ing itself out in many directions, and its future will undoubt- 

 edly be still more brilliant ; at present, although it has planted 

 its standard in numerous spots, it has fixed a government on 

 few, but still issues the central law unchanged, although with 

 explanatory extensions. The history of the atomic theory, 

 since Dalton's time, is contained in Dr. Daubeny's work, and 

 on that it is not my desire to encroach, nor could 1 hope to 

 equal it. 



A very little need be said as to the consequences of the 

 promulgation of Dalton's views. They were explained in 

 2 I 



