450 On the Cause of Chemical Proportions. [Dec. 



potash discovered by Dr. Wollaston an atom of potash should be 

 combined with 1 } atom of oxalic acid. 



I own that I do not know how these observations, and several 

 others which it would be superfluous to mention here, can be 

 reconciled with the hypothesis of atoms : but it would be rash to 

 conclude that we shall not be able hereafter to explain these ap- 

 parent anomalies in a satisfactory manner. Till that time comes, 

 the hypothesis of atoms can neither be adopted nor considered as 

 true. 



1 have already, in preceding memoirs, made mention of an- 

 other method of viewing chemical proportions — a method 

 founded on a fact discovered by Gay-Lussac ; namely, that 

 bodies when in the state of gases unite either in equal volumes. 

 or 1 volume of one combines with 2, 3, &c. volumes of the 

 other. This fact has been already verified by several distinguished 

 chemists. From what we know respecting definite proportions, 

 it follows, that it would hold with all bodies in the temperature 

 and pressure at which they would assume the gaseous lorm. 

 Hence there is no other difference between the theory of atoms 

 and that of volumes, than that the one represents bodies in a 

 solid form, the other in a gaseous form. It is clear, that what 

 in the one theory is called an atom, is in the other theory a 

 volume. In the present state of our knowledge the theory of 

 volumes has the advantage of being founded upon a well consti- 

 tuted fact, while the other has only a supposition for its founda- 

 tion. In the theory of volumes we can figure to ourselves a 

 demi-volume, while in the theory of atoms a demi-atom is an 

 absurdity. On the other hand, the theory ot volumes has a 

 disadvantage from which the atomic theory is free ; namely, the 

 existence of compound bodies, especially of an organic nature, 

 which we cannot suppose ever to have existed in the form of gas. 



I ought to observe, that we have here, as well as in the theory 

 of atoms, elementary volumes and compound volumes of the first 

 and second order. It follows from the laws of chemical propor- 

 tions, that two compound volumes, containing a common con- 

 stituent, ought to combine in such a manner that they contain 

 either equal volumes of this common constituent, or that the one 

 contains two, three, &c. times the number of volumes of the 

 other. It is almost demonstrated that an elementary volume 

 never combines with 1^ volume of another elementary substance : 

 but at present we are obliged to admit that this sometimes 

 happens with compound volumes. 



In the theory of volumes we cannot suppose the combination 

 of 2 volumes with 3, &c. : for on such a supposition there can 

 be no reason assigned why 4 volumes should not combine with 5, 

 7 with 9, 999 with 1000, &c. : so that in such a case no reason 



