690 
MESSRS. T. E. THORPE AND J. W. RODGER ON THE RELATIONS 
Values of n. 
10 Fatty hydrocarbons. 
1-9 I 
6 Iodides . 
1-7 
9 Bromides. 
1-8 
10 Chlorides. 
1-7 
5 Acids. 
1 9 
4 Ketones. 
1-9 
2 Anhydrides. 
1-7 
4 Sulphur compounds. 
1-7 
6 Aromatic hydrocarbons. 
1-7 
N itrogen peroxide. 
1-7 
W ater. 
i 
Ethyl ether. 
1-5 i 
Bromine. 
1-4 1 
Mean of means .... 1 
1 
1-76 
the GO liqulcls above given, it is evident that the value of n is, in general, 
'Oetween 1‘6 raid 1’9, and does not differ much from 176. 
From this mean value it is possible to calculate the value of the ratio of the 
viscosities at the slopes employed, that is, the value of 
Viscosity coefficient at slope 'O jOS? 
Viscosity coefficient at slope '04323 ’ 
for, by the previous discussion, the ratio is equal to 
(S4/S2)'^7' + i) or (•04987/'043'23)i'7'5'-76, 
Avhich is equal to 2'04. 
The mean value of this ratio obtained directly for the 33 liquids which could 
be compared at the two slopes, was, as already stated, 2'03, which closely agrees 
with the value obtained above by using the value of n deduced from the whole of the 
60 liquids included in the table. 
From the reasons already given regarding the unsatisfactory character of the 
method of obtaining the constants in Slotte’s formula, this agreement is of consider¬ 
able importance, and seems to indicate that formulae may yet be obtained of the type 
used by Slotte in which n is the same for all substances such as those under con¬ 
sideration. 
If this should be possible, since 
rj — p 
it is evident that p is the quantity peculiar to each liquid which should be used in 
chemico-physical comparisons. If, at present, values of p be found for each liquid 
