1876.] 



On the Analysis of Chemical Events. 



83 



VI. " The Calculus of Chemical Operations. — Part II. On the 

 Analysis of Chemical Events/'' By Sir B. C. Brodie^ Bart._, 

 F.H.S.; late Professor of Chemistry in the University of Oxford. 

 Received January 13^ 1876. 



(Abstract.) 



Inti'oduction. — An account is here given of the origin of our views of 

 the constitution of ponderable matter, regarded as constituted of units 

 compounded of "simple weights." These considerations lead to tw^o 

 systems, and two only, in which the unit of hydrogen is respectively 

 expressed by the symbols a and a. Between these systems we have no 

 absolute means of selection ; but a preference is here given to the system 

 a as immediately leading to the law of even numbers. 



The exception presented by the binoxide of nitrogen is then considered, 

 and an hypothesis suggested to account for this anomaly. 



The object of the work is then defined — namely, given a chemical 

 event, how are we to determine the events of which it is compounded ? 



Section I. — The question of the Midti]jlication and Division of chemical 

 equations is here considered. It is shown that we may multiply and 

 divide a chemical equation of the form ^^ = by any chemical function, 

 if the sum of the numerical coefficients in that equation is equal to zero, 

 but otherwise not. A method is given by which every chemical equation 

 may be brought under this form. Such an equation is termed a " nor- 

 mal " chemical equation, for it is an equation on w^hich we may operate 

 by the rules of elementary algebra. 



It is then shown that every chemical expression of the form A {x—ci) 

 (2/ — 6), and also A {x—a) (y—h) (z—c) . . . (that is, the continued pro- 

 duct of any number of such factors more than one), necessarily =0. 



As regards the interpretation of normal chemical equations. JSTormal 

 equations express the identity of the two members of the equation, not 

 only as regards matter, but as regards matter and space also. Thus the 

 equation l-l-2a^=2a + ^^ asserts not only that the matter of two units 

 of water is identical with the matter of two units of hydrogen and a unit 

 of oxygen, but also that an empty unit of space and the space occupied 

 by two units of water are identical with the space occupied by two units 

 of hydrogen and a unit of oxygeD. 



It is further shown that in any chemical equation any one of the 

 prime factors of the equation may be substituted for another, and the 

 equation will still be true. 



Section II.— Our knowledge of the identity of matter is derived from 

 chemical transmutations or events ; and every chemical equation may be 

 regarded as the record of such an event or some number of such events. 

 Chemical events may be regarded as compound or simple. A compound 

 event is defined as an event which is regarded in the system of events 

 under our consideration as constituted of tw^o or more events. A simple 



