420 M. A. Naquet on the Calculus 



identical with those of our molecules which we consider as 

 composed of several atoms. It is, in fact, absolutely identical 

 to take H = 1 and to bring all the molecules to two volumes, or 

 to bring all the molecules to one volume and to take H = J. 

 The numbers obtained would be the same in the two cases. 



Now, if Sir B. C. Brodie has been induced, by the serious 

 considerations given in his memoir, to prefer the hypothesis 

 « to the hypothesis a 2 , he does not, however, consider the hy- 

 pothesis a 2 as more metaphysical, less scientific than the other ; 

 and if it had not been his object to explain the " law of even 

 numbers," he would have adopted it*. 



With the hypothesis a 2 , there would have been nothing 

 different between our notation and that of Sir B. C. Brodie, 

 nothing except the substitution of the words " units," " dis- 

 tributed weights," " simple weights," for the words " mole- 

 cules," " molecules composed of several atoms," and 

 " atoms." Now, when it is well understood that no impor- 

 tance, no metaphysical signification, is attached to the 

 words " molecules " and atoms/'' but that the expressions 

 are simply taken as indicative of facts previously announced, 

 the question of words signifies nothing, and it matters little 

 whether the same ideas are expressed by " molecules " and 

 " atoms," or by " units," " simple or undistributed weights," 

 and " compound or distributed weights " f . It matters no 

 more than it matters whether a given thought be expressed in 

 one language or in another, provided that the expression be 

 clear and unequivocal. 



Let us go farther. Sir B. C. Brodie recognizes that certain 

 " weights " which are regarded absolutely (that is, when the 

 whole of the chemical system is considered) as u compound or 

 distributed," cannot in a limited system of operations be dis- 

 tributed, and act like " simple weights." These are " simple 

 relative weights. " Now, when we give the name of " com- 



* The fact is that ; but for the law of even numbers, the system ot could 

 not be constructed at all. — B. C. B. 



t All this is perfectly true ; but it is eminently undesirable to express 

 different ideas by the same term, which leads to confusion. The ideas ex- 

 pressed by the terms " simple weights " and " undistributed weights," 

 are not the ideas expressed by the terms " atoms " and u molecules," but 

 rather those ideas divested of what M. Naquet terms their "metaphysical 

 signification," which are not the same thing. Indeed the advocates of 

 the atomic basis of Chemistry would not, I imagine, be very well pleased 

 with M. Naquet's description of an atom as " a metaphysical entity." 



The identity of system a 2 with our present system is limited to the 

 identity of the notation by which the units of matter are expressed. The 

 Algebraical method of working with these symbols as developed in Part II., 

 which is an essential feature of this Calculus and peculiar to it, is not 

 found in our present system. — B. C. B. 



