Chemistry and Physics. 389 
allows the mercury to pass out. The upper bulb is connected 
with a water manometer and drying tube and with a capillary 
tube. The latter is attached to a larger tube 1°8 cms. in diameter 
and 4°8 cms. long, filled with copper turnings by which the gas is 
brought to any required temperature before entering the capillary. 
Both these tubes can be immersed in a vessel of cold water or in 
a tube with a double wall in which circulates the vapor of aniline 
or water. 
level of the mark. The weight of mercury gives the volume of 
gas transpired. The following table gives the result of the mea- 
surement of six gases at temperatures, 8°, 100° and 184°5°. The 
first column gives the name of the gas, the next three the coefhi- 
cients of friction at 100° and 184°5° taking the coefficient of air as 
100. The last two columns give the friction compared with that 
of air at 8°, 
0° 100° 184°5° 100° 184°5° 
ee 100 100 100 123-1 141-1 
Carbonic oxide __._ __ 96°87 er a 96-42 pace 136°0 
Carbon acid .__.____ 85°63 87°50 104°8 123°4 
Protoxide nitrogen _ 80-5 85°82 87-94 105 124°1 
oye! peat 2 60-02 61°93 73°89 87°38 
Hydrogen __.._____ 5151 51°81 
It is commonly assumed that the friction is proportional to some 
in the radiometer. In half obscurity, three radiometers were 
Placed on the interior tablet of a chamber organ. The bass notes, 
faces fj 
