76 THE ROYAL SOCIETY OF CANADA 



A diagram of the apparatus is shown in Fig. 1. The sample of 

 charcoal or lignite was placed in tube X. Around this was placed a 

 large silvered thermos vessel T containing a known quantity of water, 

 which was used as a calorimeter. The gas used was taken from K 

 which is a gas cylinder or other gas reservoir. It was carefully dried 

 by phosphorous pentoxide at A" and admitted to the apparatus at L. 

 The manometer M registers the pressure and indicates the progress 

 of the adsorption. In all those experiments the equilibrium pressure 

 was the atmospheric pressure. The heat efïect was always completed 

 thirty minutes after the experiment was started and each experiment 

 was allowed that time for the adsorption to take place. At the com- 

 pletion of the adsorption the gas was pumped out of the apparatus 

 by means of the Topler pump P into the graduated tube S to be 

 measured. If required it could then be collected over water in the 

 bottle R for subsequent analysis. 



The heat developed during the experiment was measured by the 

 rise in temperature of the water in the calorimeter. The water 

 equivalent of the calorimeter was found by inserting a small electrical 

 resistance coil and comparing the heat measured electrically with that 

 measured by the calorimeter. 



After the adsorption was completed the calorimeter was left in 

 the same position surrounding the sample tube. As the gas is pumped 

 out of the charcoal it passes through the reverse process to that when 

 the adsorption was taking place. A corresponding cooling of the 

 sample tube is then observed which would be a measure of the heat 

 due to the compression of the gas in the tube X and its condensation 

 on the surface of the sample contained in it. 



But in the case of air and oxygen chemical action will probably 

 take place. In order to obtain a measure of the heat due to this 

 source the gas pumped out was collected in bottles over water. It 

 was then made to bubble slowly through a solution of caustic potash 

 to take out any carbon dioxide that it might contain. The amount 

 of carbon dioxide was obtained by finding the increase in weight of 

 the solution after the gas had passed through it. 



The remaining gas was then passed through a tube containing 

 iodic anhydride at about 100 C°. Here any carbon monoxide that 

 it might contain is oxidized according to the reaction: 



/2O5+5CO = 72 + 5COo. 



The iodine is absorbed bv a solution of silver nitrate. The carbon 



