788 SIH B. C. BRODIE ON THE CALCULUS OF CHEMICAL OPEEATIONS. 



purpose to treat of the theory of chemical equations, which is intimately connected with 

 the general processes of chemical reasoning, and especially with the consideration of the 

 nature of that event which is termed a chemical change, of which I shall give a new 

 analysis founded on its symbolic expression. In the third part it is intended to consider 

 the principles of symbolic classification and the light thrown by this method upon the 

 origin and nature of the numerical laws which limit the distribution of weight in che- 

 mical change : I shall then have occasion to contrast the ^iew of the science which is 

 here given with that afforded by our existing system. 



It is now some years since the conception of such a work first arose in my mind, and 

 these pages are a very imperfect record of the time and consideration bestowed upon it, 

 which yet can hardly be regarded as excessive in relation to the end I have had in view, 

 which has been no other than to free the science of chemistry from the trammels im- 

 posed upon it by accumulated hypotheses, and to endow it with the most necessary of all 

 the instniments of progressive thought, an exact and rational language. " Tout langue 

 est une methode analytique, et toute methode analytique est une langue." — Condillac. 

 The views here advocated may appear novel, but nevertheless I strongly feel that one 

 claim, at least, which they have on the consideration of chemists is that they are in 

 truth the rational and simple consequence of opinions at which the most reflecting minds 

 have already arrived, and offer a more complete expression of current ideas than has 

 hitherto been given. Indeed on such subjects novelty is almost inconsistent with truth. 

 For the conceptions through which sciences pass necessarily have their origin in the 

 \iews which preceded them, of which they are but the natural fruit. The method 

 here developed will be seen, if carefully considered, to be but another step in the direc- 

 tion of the chemical movement of the last twenty years, which some imagine to have 

 found its final consummation in the doctrines of " modern chemistry." Such could 

 never have been the conclusion of the great chemists from whom this impulse emanated, 

 who definitely refused to recognize the atomic doctrine as the adequate exponent of 

 their ideas, and who implanted in the science the germ of a more abstract philosophy, 

 which it has ever since retained. 



The object of the following method has been defined as the investigation by means 

 of symbols of the laws of the distribution of weight in chemical change, a problem 

 evidently of the widest range, and embracing many distinct questions. To the con- 

 sideration of one, and certainly not the least important, of these the first part of this 

 work will be more especially devoted, namely, to the discovery of a system of symbolic 

 expressions by which the composition of the units of weight of chemical substances may 

 be accurately represented, and which may hereafter be employed for the purposes of 

 chemical reasoning. The value of our conclusions must depend upon the degree of 

 precision and certainty with which this point is determined. It will be showTi that the 

 problem is of a perfectly real nature, admitting, where the experimental data are 

 adequately supplied, of only one solution. The discussion of this question involves the 

 consideration of the fundamental principles of symbolic expression in chemistry. 



