448 DR LYON PLAYFAIR AND MR J. A. WANKLYN ON A MODE OF 
C. EXPERIMENTS WITH ETHER WHICH HAD BEEN PURIFIED AND DRIED WITH GREAT CARE. 
Weight of Ether taken = -0808 grm. 
Vol. in Cubic 












Observed volume c 
in Cubic Centi- Temperature C. pia Nee San co eauee 
BAG Millimeters. 
Vol. of Dry Hydrogen, . 55:09 6°5° 557°4 
Hydrogen and Ether Vapour 94-0 69:5° 653-8 64-466 
—=Obset,: (emp eG. oF 
ES aaa } 82:97 | § 20:8° 631°8 64-094 
Temperature. Vapour Density. 
Observation 1 at 69°5° 2-499 
3 2 at 20°8° 2°539 
Eaperiment without Hydrogen. 
Weight of Ether taken = -1702 grm. 
Vol. in Cubic 
Cent. corrected 
at 0° C. and 760 
Observed volume 
in Cubic Centi- re 
HE Millimeters. 
meters. 

Ether Vapour—Obs. 1, : 
80°49 
94° 

Ether Vapour—Obs. 2, . 
72°38 
52° 
659°7 
640°3 
Millimeters. 
51:985 
51:232 

A correction of 0°2 c.c. has to be made for air in the bulb. 
Temperature. Vapour Density. 
Observation 1 at 94° C. : 
2 at 52° C. 2'580 
29 
The theoretical vapour density of ether is 5 x -0691 = 25567. 
From these experiments we see that the vapours of alcohol and ether do not — 
depart widely from the true gaseous character. When mixed with hydrogen, 
they preserve their specific gravity at temperatures much below the boiling points 
of their liquids. 
The specific gravity of a gas is the quotient obtained by dividing the weight 
of a given volume of gas by that of the same volume of air under similar condi- — 
tions of pressure and temperature. Ifthe gas in question behave exactly like air 
when exposed to varying pressures and temperatures, the specific gravity of the 
gas must be invariable. If, on the other hand, the gas should not follow 
Marriortr’s law, or have an expansion coefficient different from that of air, the - 
specific gravity of the gas would be a varying quantity. 
The foregoing considerations will render intelligible the following inference q 
drawn from our experiments on alcohol and ether. We have shown that the — 
specific gravity of either of these vapours is lower when taken in presence of © 

