[EDWARDS-EL worthy] CONTINUOUS FLOW APPARATUS 



51 



the first set of tubes was revivified for use, when the second set became 

 saturated. 



The Preparation of the Charcoal 



The charcoal used in the tubes was prepared by heating frag- 

 ments of cocoanut shell out of contact with air in a muffle furnace at a 

 temperature of about 800°C. for ten hours. When cool, the pieces 

 were crushed and screened, that which passsed 10 but was retained 

 by 30 meshes to the inch, being used. 



After being put in the tubes the charcoal was again heated in 

 vacuo. Each tube held about 30 grams. 



The Revivification of the Charcoal 



When saturated the tubes were allowed to warm up to atmos- 

 pheric temperature while the gas given off was withdrawn. The 

 tubes were raised to about 200°C. by means of cylindrical electric 

 heaters and after half-an-hour a vacuum pump was connected and 

 the tubes thoroughly exhausted and allowed to cool. The tests have 

 shown that the absorptive power of the charcoal is not decreased by 

 successive treatments, but is rather increased, a fact confirmed by 

 LemonS working on the critical temperatures at which absorbed 

 gases are evolved from charcoal. 



Results 



Altogether, seven runs were made, with the object of testing the 

 efficiency of the method, the quantity of gas that could be purified 

 by the amount of charcoal used (90 grams), the maximum rate the 

 gas could be passed through the apparatus, and the efficacy of the 

 revivification process. The following particulars outline the salient 

 features of the runs: 



There was no indication that the charcoal was saturated when the run was stopped. 



II 



5-27 

 0-83 



17-61 

 3-9 



15 

 60 



99-9 

 99-9 



At the end of Run I the charcoal tubes of Set 1 were only pumped out by means 

 of aspirator bottles, accounting for low figure for saturation. 



1 Signifies that the charcoal was saturated. 



1 Lemon. Physical Review 9, p. 336, 1917. 



