464 
MESSRS. T. E. THORPE AHD J. W. RODGER OH THE RELATIONS 
Ill reducing the observations we have adoj^ted the value = 0‘7074 for the 
relative density, and the expression 
V = 1 + 0-03l3426« + 0-0o34339^2 + 0-0738693^3 
for the thermal expansion (Zander. ‘ Annalen.,’ 214, 148). 
Taking 
= -003374 7^3 -001966 (calculated) = -002576 
— 0°-37, ^3 = 56°-20, t .2 (from curve) = 26°-34, 
we obtain the formula. 
72-193 
“ (173-01 + 0™ ’ 
•which gives results in good agreement with those obtained by observation. 
Mean temp. 
Difference. 
Observed (mean). 
Calculated. 
O 
0-37 
•003374 
•003374 
•000000 
5-95 
•003169 
•003174 
d- ’000005 
10-78 
•003010 
•003014 
+ -000004 
15-46 
•00286G 
•002871 
+ -000005 
20-76 
•002719 
•002721 
+ -000002 
25-46 
•002599 
•002595 
- -000004 
30-71 
-002474 
•002470 
- -000004 
36-()G 
-002355 
•002349 
- -000006 
41-99 
•002229 
•002226 
- -000003 
46-76 
•002137 
•0021.33 
- -000004 
51-.54 
•002047 
•002046 
- -000001 
56-20 
•00196G 
•001966 
•000000 
Iodides. 
Methyl Iodide. CTIgl. 
A quantity of “ pure” methyl iodide, after standing for some days over phosphoric 
oxide, was sliaken with “molecular ’’silver and distilled. It boiled between 42°-36 
and 42°-40. Bar. 746-2 millims. Corrected and reduced li.p. = 42°-91. 
Vapour density : 
Found, 70-49. Calculated, 70-75. 
The liquid was quite colourless and remained so throughout the observations. 
Observations for viscosity :— 
