368 W. G. Mixter — Deportment of Charcoal with 



Experiment 11±. — 9 - 6 grams of lampblack were chlorinated 

 by heating for an hour in chlorine, and then allowed to cool in 

 a current of gas. After standing for a day the product was 

 burned in a current of dry oxygen. In the cool and narrowed 

 part of the combustion tube a slight sublimate formed not 

 sufficient for a quantitative analysis. It was found to con- 

 tain chlorine and to burn with a smoky flame. The gaseous 

 products of the combustion were passed through dilute 

 ammonia on which a slight oily product collected. There 

 was a little loss of chlorine in the fume which escaped from 

 the ammonia which was found to contain, after the combustion 

 was finished, 2*638 grams of chlorine, showing that the lamp- 

 black had taken up 27 per cent of its weight of chlorine. 



Experiment 15. — Native graphite was ignited for two hours 

 in chlorine, which was then displaced while hot by air. The 

 graphite retained but a trace of chlorine, owing doubtless to 

 impurities. 



Experiment 16. — Half a gram of fragments of white dia- 

 monds remained unchanged in weight after ignition in chlorine 

 for an hour. 



Chloroform, benzene, alcohol and ether failed to dissolve 

 anything from chlorinated lampblack. Boiling dilute ammo- 

 nia water removed a little chlorine, but the lampblack after 

 protracted digestion with ammonia retained chlorine. A por- 

 tion of the chlorinated lampblack of 3 which had been heated 

 in vacuo and contained 8 - 5 per cent of chlorine was mixed 

 intimately with artificial alumina. The mixture gave no subli- 

 mate on heating in a glass tube in the blast lamp. The test 

 was repeated with a new mixture and the tube containing it 

 was heated in a combustion furnace for half an hour. No 

 sublimate formed, but on passing chlorine over the mixture 

 aluminum chloride appeared at once and was rapidly deposited 

 in the cool part of the tube. Gas carbon, alumina and chlo- 

 rine yielded at a red heat only slowly a small quantity of 

 aluminum chloride. 



The foregoing experiments were made to find whether 

 chlorine held by charcoal at high temperatures is occluded, 

 that is condensed in the pores and on the surface or is chem- 

 ically combined with the carbon. It is not probable that the 

 chlorine is occluded since gases condensed by charcoal are 

 given off in vacuo on heating. If the chlorine were occluded 

 then we should expect that bromine and iodine would be held 

 in larger quantity by charcoal, as the more readily condensible 

 gases are absorbed in the largest quantity, but glowing char- 

 coal retains less bromine than chlorine and still less iodine. 

 Charcoal facilitates combination of gases but when hydrogen 



