Tetravalency of Oxygen. 235 



could say, for instance, that chlorine is usually monovalent 

 but occasionally tecvalid. The latin prefixes, roman numbers, 

 and broken lines in formulas would help to keep up the dis- 

 tinction : thus : — 



-B/ monovalent, 



— R 1 



univalid. 



=R" divalent, 



^R 11 



bivalid. 



R'" trivalent, 



=I& 



tervalid. 



fR"" tetravalent, 



^R 1 ^ 



quadrivalid, &c, 



We might then say that carbon is tetravalent, except in 

 the gaseous molecules CO and CNH, where it is bivalid 

 unless the tetravalency of oxygen and the pentavalency of 

 nitrogen are admitted, when carbon is always tetravalent*. 



C=0 and C=N— H. 



Other open questions will suggest themselves to the mindf. 



The general chemical observation that no atom is really 

 known to be more than hexavalent to the standard monovalent 

 atomsj finds remarkable independent support in Prof, J. J. 

 Thomson's development of the vortex-atom theory. According 

 to his view a triad atom consists of three vortex rings sym- 

 metrically linked together, and " no element could have an 

 atom consisting of more than six vortex rings." He has also 

 found that stable motion exists " when the distance between 

 the rings was small compared with their apertures," and he 

 adds: " We found that for each displacement there are two 

 periods of vibration, a quick vibration and a slow one." Is 

 it possible, it may be asked, that in these two periods of 

 vibration there is a connexion with the two valencies or rather 

 the valency and validity of so many of the negative or non- 

 metallic elements which have been referred to in this paper ? 



Prof. J. J. Thomson at least clearly points out that, ac- 

 cording to the vortex-atom theory of gases, " one atom of a 



■ * In CO, according to Prof. J. J. Thomson's conception of links, ft the 

 atom of carbon has the same number of links as the atom of oxygen." 



t CNH and NCH are metameric molecules. It is not easy to decide 

 which is the formula of prussic " acid " gas. In the formula, I have 

 assumed it to be the " iniido " relative of CO, which is metameric with 



H 

 formo-nitrile, | . The two methyl and ethyl metamers seem distin- 



CH 

 guishable, but sometimes turn up together in u the same " reaction. 



I The cases of M VI1 and M VI11 are here considered as not proven. Prof. 

 J. J. Thomson's views on this point will doubtless be dealt with in the 

 course of further chemical research. 



