468 MESSRS. T. E. THORPE AND J. W. RODGER ON" THE RELATIONS 
In reducing the observations we have adopted = 17829 for the relative 
density, and the expression 
V = 1 + -0310276^ + -0318658^2 - -OjoSOS^s 
for the thermal expansion (Dobrinee, loc. cit.). 
Takinof 
Pi = '009336 7]o = '003621 p.j (calculated) 
Lj = O^’^SO to = 98°'89 (from curve) 
we obtain 
50-893 
“■ (136-84 + ^)i'7483 ’ 
which gives results in good agreement with those obtained by observation. 
= '005814 
= 42°'96, 
Mean temp. 
'/• 
Difference. 
Observed (mean). 
Calculated. 
O 
0-30 
-00934 
•00934 
•00000 
10-98 
-00817 
•00819 
+ -00002 
20-81 
•00730 
•00732 
+ -00002 
28-31 
•00673 
•00674 
+ -00001 
38-83 
•00605 
•00605 
•00000 
4G 17 
•00564 
•00564 
•00000 
55-59 
-00516 
•00516 
•00000 
05-46 
•00474 
•00473 
- -00001 
74-38 
•00439 
•00439 
•00000 
83-88 
•00406 
•00406 
•00000 
90-78 
•00384 
•00385 
+ -00001 
98-89 
•00362 
•00362 
•00000 
Iso-pr<)j)yl Iodide. (CH 3 ) 3 CHI. 
A cpiantity of isopropyl iodide, obtained from Kahlbaum, was placed for some 
days over phosphoric oxide, and after decantation shaken with “ molecular ” silver to 
remove free iodine. It was tlien fractionated, when the main portion was found to 
boil between 89°'40 and 89°'58. Bar. 753'5 millims. Corrected and reduced 
b.p. = 89°'7. 
No valid determination of vapour density could be obtained, or indeed expected, 
owing to the rapidity with which the iodide changes on exposure to heat and light. 
The ol)servations for viscosity gave :— 
