67G . 
MESSRS. T. E. THORPE AND J. W. RODGER OH THE RELATIONS 
The differences between the magnitudes of the properties of the two chlorine 
coin 2 :)Ounds are never in harmony with the fairly concordant differences obtained from 
the other pairs of compounds, the members of which differ in composition by a carbon 
atom and a double linkage. 
Aldehyde and Acetone .—As already stated, the observed values of these substances 
were not employed in deducing the fundamental constants. 
Using the values for C, H, and O, the observed and calculated numbers are :— 
I 
Observed. 
Calculated. 
Difference 
per cent. 
Aldehyde . 
169 
141 
16 
Acetone . 
238 
221 
7 
Uus large difference in the case of aldehyde points to the difference in constitution 
between the aldehydes and the ketones, as the value of oxygen used in obtaining the 
calculated number is that of ketonic oxygen. The difference is to be ascribed to the 
fact that different values have to be given to carbonyl in the groups 
R_C_H and K—C—R. 
II II 
o o 
just as different values have to be given to oxygen in the groups R.O.H 
(hydroxyl oxygen) and R.O.R (ether oxygen). A stud}^ of other aldehydes 
would have to be undertaken to decide this point. The large observed value for 
acetone is somewhat difficult to explain on purely chemical grounds. It is possibly 
due to the symmetry of the molecule, although the evidence is somewhat unsatis¬ 
factory. The symmetrical compound Et.CO.Et. gives an observed value which is 
smaller than that obtained by calculation; possibly, as already mentioned, the 
character of the diethyl ketone ma}^ have affected the result. On comparing ethylene 
and ethylidene chlorides it has been seen that the symmetrical compound differs 
from the unsynnuetrical compound just as acetone appears to differ from ketones 
like Me.CO.Et. and Me.CO.Pr; the symmetrical compouuds having the larger 
values. I'he most probable cause of the peculiar behaviour of acetone is indicated, 
however, by surface-energy measurements, which point to the conclusion that 
acetone contains molecular aggregates, whereas methyl propyl ketone, and thus 
presumably higher homologues of acetone, do not. (Ramsay and Shields, loc. cit.) 
Carhon Bisulphide .—The calculated value for carbon bisulphide, using the constant 
for singly-linked sulpluir, is 43G. The observed value is 241. 
It is evident, however, that in carbon bisulphide we are dealing Avith doubly-linked 
