The rate of flow of air and of carbon dioxide through a porous plug

The object of this experiment is to study the rate of flow of air through a porous plug as affected by (a) pressure difference between the ends of the plug up to 110 centimeters of water; (b) absolute pressure from 75 to 110 centimeters of mercury; (c) temperature from 0 to 80 degrees Centigrade, that is 273 to 353 degrees absolute; and to observe any differences and similarities in the behavior of carbon dioxide.