510 MESSRS. T. E. THORPE AND J. W. RODGER ON THE RELATIONS 
of Ramsay and Young, Iiowever, render it possible to calculate the vapour density 
of the pure acid at different temperatures and pressures, W e accordingly made a 
determination of the vapour density of the acid employed by us with the following 
results :— 
Weight of liquid, 0‘0T55 grm. Volume of vapour, 79’8 cub. centims. 
Temperature, 100°‘66. Pressure, 240'3 millims. 
Found, 45*73. 
Calculated (R. and Y,), 45*8. 
The observations for viscosity gave :— 
Left limb. 
Right limb. 
Temp. 
Press. 
Corr. 
V- 
Temp. 
Press. 
Corr. 
'/• 
13-23 
128-79 
-000028 
•013577 
13-70 
128-73 
•000028 
•013605 
21-90 
128-68 
-000031 
•011761 
21-93 
128-60 
•000032 
•011761 
30-87 
128-63 
-000036 
•010247 
30-86 
128-54 
•000036 
•010257 
39-91 
128-59 
•000040 
•009026 
39-85 
128-47 
•000040 
■009037 
1 48-50 
128-51 
•000045 
•008055 
48-45 
128-42 
•000045 
•008059 
57-46 
128-33 
•000049 
•007201 
67-45 
128-39 
•000049 
•007221 
68-16 
128-59 
•000055 
•006373 
68-06 
128-50 
-000055 
•006383 
76-60 
128-60 
•000060 
•005807 
76-72 
128-47 
•000060 
•005800 
84-52 
128-64 
•000064 
•005.338 
84-55 
1-28-52 
•000064 
•005344 
93-96 
128-72 
•000070 
•004844 
93-99 
1-28-60 
•000070 
•004845 
103-90 
128-90 
•000076 
•004409 
101-89 
128-70 
•000075 
•004490 
112-47 
128-92 
•000081 
•004067 
112-67 
128-83 
•000081 
•004056 
For the relative density we have adopted the mean of the closely concordant values 
of Rosooe, Landolt, Oudemans, and Zander, viz., cl (0°/0°) = 1*0711, and for the 
thermal expansion the mean of the formulae given by Kopp and Zander : 
V = 1 -j- ‘0.^106001t + *0el5479i2 + *07102597^1 
Taking 
rj^ = *010252 7)q = *004062 rjo (calculated) = *006453 
q = 30°*86 C = 112°*57 C (from curve) = 67°*12, 
we obtain the formula 
267-814 
Vt — (119-207 + 0™ ’ 
vliicli gives values which agree closely with those obtained by^ observation at 
temperatures above 30°. 
