446 DR LYON PLAYFAIR AND MR J. A. WANKLYN ON A MODE OF 
If the other observations be calculated, the numbers will be found to differ 
very little from that obtained from the first ; indeed Observation 3d, which de- 
parts furthest from Observation Ist, gives for the vapour density the quantity 
1-522. 
The same sample of moist alcohol was made the subject of an experiment, in 
which its vapour density was determined in the usual way, without the employ- 
ment of a permanent gas :— 
Weight of Alcohol taken =-0792 grm. 
Observed volume Vol. in Cubic 
Pressure in C 
in Cubic Centi- | Temperature C. Tq: Jent. corrected 
Caetore. I Millimeters. at 0° C. and 760 

Observation], ... . 63°48 95° 636-8 


Observation 2, G01 te : 681°5 

From which is deduced :— 
Temperature. Vapour density. 
95" : ? ; 1551 
oo : : : 1-565 
In the first described experiment, where hydrogen was present, we found the 
vapour density of the alcohol to lie between 1:508 and 1522. It would appear, 
therefore, that the presence of hydrogen lowers the vapour density of alcohol 
vapour; the lowering cannot be due to difference of pressure, for in the experi- 
ment where the higher vapour density was obtained, the pressure was about 
630 millimeters, whilst in the other experiment it was about 730. 
B. EXPERIMENTS WITH PERFECTLY ANHYDROUS ALCOHOL. 
Weight of the Alcohol taken = :0889 grm. 



Vol. in Cubic 
Pressure in Cent. corrected 
Millimeters. at 0° C. and 760] — 
Millimeters. 



Observed volume 
in Cubic Centi- | Temperature C. 
meters. 







Vol. of Dry Hydrogen, . . 43°16 ia 572-07 










Hydrogen and Alcohol Va- 11084 99° 710-6 
pour—Observation 1, . 
Hydrogen and Alcohol Va- ; se : 
ee = Obs 2m 107:16 83°5 699-7 
Hydrogen and Alcohol Va- : ° : 
Ler mantagh fy } 102-74 68 695-1 

