OF THE PARA.FFHTS AND THEIR MONOHALOGEN DERIVATIVES. 
21 
j) =z the pressure of the gas in the Kundt tube. 
t = the temperature of the gas in the Kundt tube. 
I = the half wave-length in methyl chloride. 
V — the half wave-length in air. 
p = the S.G. of the methyl chloride at the pressure given in the first column. 
Table VI. 
p- 
t 
1 . 
V. 
/>■ 
1 + I 'blf. 
p dv 
7- 
380 
16 
34-94 
48-89 
]-754 
1-007 
1-271 
580 
15-2 
34-65 
48-55 
1-761 
1-014 
1-280 
600 
16 
34-73 
48-68 
1-762 
1-014 
1-280 
680 
16-3 
.34-72 
48-63 
1-766 
1-015 
1-286 
Mean . 
1-279 
In the last experiment there was 1‘05 per cent, of air in the gas; the result is 
corrected for this. 
§ 6. Methyl Bromide. 
The material was obtained from Kahlbaum, and was dried with calcium chloride 
and redistilled. 
The results of the vapour density determinations are shown in Table VII. and fig. 8. 
Table VII. 
P- 
t. 
/'• 
131 
15-8 
3-265 
22 ] 
15-6 
3-275 
451 
15-9 
3-305 
Fig. 8. 
2( 
51 
