256 Mr. J. J. Waterston on Chemical Notation in 



a cubic foot of the vapours of ether, of alcohol, and of all other 

 compounds of oxygen and other bodies, simple or composite, 

 contains ~n number of atoms or smallest parts of the respective 

 compounds, then must a cubic foot of oxygen contain n atoms : 

 or giving to the ultimate moving part of a gas or vapour che 

 name molecule, we find that in all compounds containing oxygen 

 the atom of each corresponds to the molecule, and has the same 

 constant volume in all, if we regard only the molecule of oxygen 

 to be dual in its nature, or composed of two atoms. Reverting 

 to the usual definition of gaseous volume being the quotient of 

 the equivalent weight by the specific gravity, we have to make 

 an exception to this in the case of the primaries, and define their 

 gaseous volume as being the quotient of twice the equivalent 

 weight by the specific gravity ; but it would be better to substi- 

 tute the word molecule for volume, as the theory of heat and 

 gases which attributes to the ultimate separate part, whatever 

 its weight or constitution, a constant volume, because of the vis 

 viva with which it is charged, seems to be favourably received by 

 professional chemists (Graham, vol. ii.). 



With respect to ethyle, &c, and the " rational formulae" in 

 which they enter, some further remarks seem necessary, as the 

 existence of such radicals is incompatible with the dynamical 

 theory. In the 'English Cyclopaedia/ art. "Chemical Formula?," 

 the following occurs : — u All formulas are partial because they 

 cannot express the whole of the molecular arrangements of the 

 bodies to which they refer, and arbitrary because they cannot 

 but give undue prominence to particular theoretical views and 

 tendencies." In Graham's second volume, p. 521, it is stated 

 that " the rational formula of a compound is inferred from its 

 modes of formation and decomposition." Such mode applied to 

 alcohol would define it as a hydrate of olefiant gas. At p. 522 

 the following occurs : — " It appears, then, that the same com- 

 pound may have several rational formula? The greater 



the number of elementary atoms entering into the constitution 

 of a compound, the more numerous will be the possible arrange- 

 ments of those atoms, and the greater therefore the number of 

 rational formula? which may be assigned to the compound." It 

 thus appears that rational formula? are as yet little better than 

 possible arrangements, and the insufficiency of the chemical evi- 

 dence to determine one in preference to another is admitted. To 

 those who consider the truth in nature as of paramount import- 

 ance, here is a motive for seeking evidence in departments not 

 strictly chemical, more especially since the discovery of the alcohol- 

 mixed metals, and of hydrocarbons having the constitution of 

 ethyle and methyle, seem to be regarded as settling the point in 

 favour of the modern theory. 



