﻿of Carbon Oxysulphide and Carbon Bisulphide. 293 



complete expression in the theory of Lewis unci Langmuir *, 

 particularly in relation to the type of compound with which 

 this paper is concerned — namely, that in which atoms, 

 deficient in electrons, are regarded as sharing- them in order 

 to reach the completeness of inert configurations. The main 

 purpose of this paper is to apply the principles of this theory 

 to the special case of the molecule of carbon oxysulphide, 

 and to show that the molecular dimensions of this compound, 

 as derived from viscosity data, are consistent with the Lewis- 

 Langmuir view of its constitution. This test of the validity 

 of the theory is made possible by the recent measurements 

 by 0. J. Smith t of the viscous properties of the gas in 

 question. Similar calculations for the molecule of carbon 

 bisulphide have been made, and these await verification or 

 otherwise when the necessary viscosity data are available. 



3. Carbon oxysulphide belongs to a family of three 

 compounds having the chemical constitutions C0 2 , COS, and 

 CS 2 . The two former are gaseous at ordinary temperatures, 

 and the latter a highly volatile liquid. In all of them carbon 

 is a constituent, and COS can he regarded as the molecule 

 obtained by the substitution of a sulphur atom for one of the 

 oxygen atoms in C0 2 , or by the reverse substitution in CS 2 . 

 It is probable that the carbon atom occupies the central 

 position in each molecule, and that the nuclei of the three 

 atoms lie in each case upon a straight line. 



4. According to the Lewis-Langmuir theory (loc. cit.), the 

 atoms in these molecules are linked together by sharing 

 external electrons in such a manner that each atom approxi- 

 mates to the configuration of the inert atom at the end of the 

 corresponding row in the periodic table. Thus, in C0 2 the 

 central carbon atom shares altogether eight electrons, four on 

 each side with an oxygen atom. The electron configuration 

 thus formed is that of three neon atoms in a row, for the 

 inert atom corresponding to both carbon and oxygen is neon. 

 In the molecule COS there are again eight electrons shared 

 by the carbon atom, four on one side with the oxygen atom, 

 and four on the other side with the sulphur atom. The 

 electron arrangement thus attained is that of two neon atoms 

 (corresponding to the oxygen and carbon) and one argon 

 atom (corresponding to the sulphur). Applying a similar 

 argument to the CS 2 molecule, we are led to regard it as 

 resembling closely the electron distribution of inert atoms 

 in the sequence argon-neon-argon in a line. In other 

 words, we can treat each carbon or oxygen atom in a 



* I. Langmuir, Joura. Amer. Chem. Soc. vol. xli. p. 8C>8. 

 t C. J. Smith, supra, p. 289. 



