"In all chemical investigations, it has justly been considered an important object to ascertain the relative weights of the simples which constitute a compound. But unfortunately the enquiry has terminated here; whereas from the relative weights in the mass, the relative weights of the ultimate particles or atoms of the bodies might have been inferred, from which their number and weight in various other compounds would appear, in order to assist and to guide future investigations, and to correct their results. Now it is one great object of this work, to shew the importance and advantage of ascertaining the relative weights of the ultimate particles, both of simple and compound bodies, the number of simple elementary particles which constitute one compound particle, and the number of less compound particles which enter into the formation of one more compound particle. If there are two bodies, A and B, which are disposed to combine, the following is the order in which the combinations may take place, beginning with the most simple: namely, 1 atom of A + 1 atom of B = 1 atom of C, binary 1 atom of A + 2 atoms of B = 1 atom of D, ternary 2 atoms of A + 1 atom of B = 1 atom of E, ternary 1 atom of A + 3 atoms of B = 1 atom of F, quaternary 3 atoms of A and 1 atom of B = 1 atom of G, quaternary"