618 
MESSRS. T. E. THORPE AND J. W. RODGER ON THE RELATIONS 
1'he substances are classified into two groups—Table A and Table B—as in tlie 
case of molecular viscosity, according as the differences are less or greater than about 
5 per cent. 
Molecular Viscosity Work at the Boiling-point. 
Table A. 
Observed. 
Calculated. 
Difference 
per cent. 
Pentane . 
235 
232 
1-2 
Hexane . 
285 
279 
21 
Heptane. 
323 
.326 
- 0-9 
Octane. 
369 
373 
- IT 
Isopentane . 
240 
237 
1-2 
Isohexane . 
286 
284 
0-7 
Isoheptane.. 
321 
331 
- .31 
Amylene. 
200 
209 
— 4'5 
Methyl iodide. 
256 
278 
- 8-6 
Ethyl iodide. 
318 
325 
- 2'2 
Propyl iodide. 
377 
377 
1-3 
Isopropyl iodide. 
389 
372 
4-4 
Isobutyi iodide. 
435 
424 
2-5 
Allyl iodide. 
347 
344 
0-8 ; 
Ethyl bromide. 
255 
268 
1 
- 5T 
Propyl bromide. 
315 
315 
0 
Isopropyl bromide. 
326 
320 
1-8 
Isobutyl bromide. 
376 
367 
2-4 
Allyl bromide. 
285 
287 
- 0-7 
Ethylene dibromide .... 
501 
518 
- 3-4 
1 
Propyl chloride. 
251 
248 
1-2 
Isopropyl chloride. 
258 
253 
1-9 
Isobutyi chloride. 
318 
300 
5-7 
Allyl chloride. 
221 
220 
0-5 
Ethylidene dichloride .... 
308 
312 
- 1-3 
Carbon tetrachloride .... 
506 
486 
3-9 
Methyl sulphide. 
190 
190 
0 i 
Ethyl sulphide. 
283 
284 
- 0-4 j 
Dimethyl ketone. 
179 
181 
- IT 
Methyl ethyl ketone .... 
231 
228 
1-3 
Methyl propyl ketone .... 
277 
275 
0-7 
Diethyl ketone. 
261 
275 
— 5'4 
