﻿Dimensions of Gaseous Carbon Oxysulphide. 291 



Table I. 

 Each time recorded is the mean of four observations in each 

 direction for the whole pellet, and of three for the pellet wh 

 divided into two segments. The letters in parent heses indicate t 



order in which the observations were made. 



en 

 the 



Temp. 



(deg. C). 



Time of fall (sees.). 



Capillary 



correction 



(.r). 



Corrected 



time 



(0- 



Time at 



Whole 

 pellet. 



Two 



segments. 



15°0C. 



ioo°-oc. 



(a) 1529... 



73-04 



7635 



00416) 



7001 



69-92 





(6) 15-44... 



73-08 



76-25 



00399 



70-16 



7005 



— 



(e) 15-63 ... 



7302 



7622 



0-0403 



70-07 

 Mean 



69-91 

 69-96 



— 



(c)99-9 ... 



91-51 



92-43 



0-0099 



90-60 



— 



9063 



(rf)99-9 ... 



91-54 



92-48 



o-oioi 



90 62 

 Mean 



— 



90-65 

 9064 



Assuming Sutherland's law to hold for this gas, the value 

 of Sutherland's constant obtained is C = 330. 

 Also at 15°'0 C, 



/cos = 69'96 

 4 ir 104*71) 



= 0-6682. 



Correcting for difference of slipping of COS and ah\, we 

 obtain 



259i= 0-6668. 



fail- 

 Oil the assumption that the viscosity of air at 15°0 C. is 

 1-799 x 10- 4 C.G.S. units, the values for COS are 



Vl .= 1-200 x 10" 4 C.G.S. units 

 and ?7 100 = 1*554 x 10" 4 C.G.S. units ; 



and by extrapolation using Sutherland's formula, 

 ^=1-135x10- 'C.G.S. units. 



Calculation of Molecular Dimensions. 



The particular dimension calculated from the above 

 results is the mean area A which the molecule presents in 

 mutual collision with others. The basis of this calculation 

 is Chapman's formula (Joe. cit.) modified in its interpretation 

 in the manner suggested by Rankine. The value obtained 

 is A = 106 x 10 _ir ' cm. 2 which may be subject to an error of 

 2 or 3 per cent. 



U2 



