102 



LAW OF EQUIVALENCY 



PART I. 



decomposition are exactly the same with those deter- 

 mined by composition, and thus the atomic weights 

 derived from electro-decomposition accord exactly with 

 those obtained from chemical composition. Moreover, 

 Mr. Faraday, as already mentioned, proved that the very 

 same quantity of electricity necessary to decompose a 

 body into its elementary atoms, is requisite to unite 

 them again. The analysis and synthesis of compound 

 matter, solid or. fluid, show a constant and definite 

 proportion of the component elements expressed by 

 number, and by an equivalent or multiple ratio of parts 

 in every chemical change. 



The atomic theory unites, by a common bond, specific 

 gravity, chemical affinity, heat, and electricity. Taking 

 atmospheric air at the temperature of 60 Fahr. and 

 a barometric pressure at 30 inches as the standard 

 unit of specific gravity ; the quantity of heat required 

 to raise a volume of water 1 Fahr. as the unit of 

 specific heat ; hydrogen gas as the unit of atomic 

 weight ; and atomic electro-chemical electricity as the 

 unit of specific electricity, the following numbers have 

 been established : 



The distances between the atoms of the gases are 

 equal, hence the atomic weights of simple gases are 

 proportional to their densities ; and for the same reason, 

 equal volumes of the same fluid contain an equal num- 

 ber of atoms, and the number of atoms in the same 

 volume of different fluids is in the simple ratio of one 

 to one, one to two, one to three, &c. 



