BETWEEN THE VISCOSITY OF LIQUIDS AND THEIR CHEMICAL NATURE. 668 
The average divergence from the mean is less than 4. The percentage vaiiation 
is greater, however, than for most of the other atomic constants. The vahie is 
probably affected by the complexity of the acids. 
’ . II • II \ , \ / 
Taking O = — 19, and O + 0 = 81, it follows that in the acids O = 100. 
Ether Oxygen. —Using the preceding values of C, H, and 0, the observed numbers 
for acetic anhydride and ether give respectively 44 and 42 as values for ether oxygen ; 
with such scanty data as are to hand it is therefore probable that 
0< = 43. 
The mean values thus obtained for oxygen in different conditions are 
'i \ / 
O — - 19, 0=100, 0< = 43. 
Value of Sulphur. 
The two comparisons available for obtaining values for singly-linked sulphur 
are given below : — 
Sulphide. 
“ Rest ” 
\/ 
(calculated). 
S. 
//tP (observed). 
Methyl. 
240 
92 
148 
Ethyl . 
393 
232 
141 
]\rean value of S = 144. 
Influence of Ring-Grouping. 
On calculating values for the molecular viscosity work of the aromatic hydrocarbons 
ill the same way as has been described when dealing with molecular viscosity, tlie 
differences given in the subjoined table, representing the effect of the ring-grouping, 
are obtained. 
(observed). 
“Rest” 
(calculated). 
Ring-grouping. 
Benzene . 
314 
684 
-370 
Toluene. 
396 
764 
-368 
Ethyl benzene. 
475 
844 
-369 
Ortho-xylene. 
483 
844 
-361 
Meta-xylene. 
474 
844 
-370 
Para-xylene. 
467 
844 
-377 
jMean value of ring-grouping = — 369. 
