ATOMIC WEIGHTS 135 



Jaquerod and Seheuer/ from the same density figures, but with, measure- 

 ments of compressibility, found S = 32.036. 



The density determinations by Baume ' are much more elaborate. Two 

 series were made, in globes of different capacity, and at pressures varying 

 slightly from the normal. His crude figures for the weight of a litre 

 of sulphur dioxide are as follows : 



Series I. Series II. 



2.92886 2.92662 



2.92592 2.92718 



2.92683 2.92€32 



2.92500 2.92711 



2.92623 



Mean of both series as one, 2.92667, ±.00030. As corrected by Baume 

 the normal litre of SOo weighs 3.92661 grammes. Morley's value for the 

 normal litre of oxygen is 1.42896, ±.000028 grammes. Hence the ratio 

 0.: SO.:: 32: 65. 538, ±.0067. This combines with the previous series 

 thus : 



Leduc 65.553, ± .0020 



Jaquerod and Pintza 6.5.528, ± .0020 



Baume 65.538, ± .0067 



General mean 65.540, ± .0014 



Guye,' in his recalculation of the density ratio for SO,, assigns to the 

 weight of the normal litre of oxygen the value 1.4290, and to SOo the 

 value 2.9266. Hence the crude ratio is 65.536, which is close to Baume's 

 figure and also near the general mean as given above. In reducing this 

 by means of the critical constants he assumes 0^ = 0.02644, and &o = 

 0.00255. Baume, on the other hand, finds ^0 = 0.02837, and &„ = 0.00267. 

 The formula for reduction, as employed in relation to the carbon and 

 nitrogen gases, is 



22.4 12L 



(T+^a — ^o) 



Hence, using Guye's value for L, which is sensibly identical with that 

 of Baume, we have — 



By Guye's critical data SO, = 64.065 



By Baume's critical data SOo = 63.952 



The difference between these figures shows the uncertainty of the 

 method as applied to sulphur dioxide. If we accept Guye's figures, as 



1 Compt. Rend., 140, 1384. 1905. 

 2Journ. Chim. Phys., 6, 43. 1908. 

 3 Journ. Chim. Phys., 3, 321. 1905. 



