MR, H. BRKRETON ItAKKR ON COMBUSTION IN DRIED OXYGEN. 591 



Geneiftl Conclusions. 



1. Pure charcoal, heated in oxygen dried by phosphorus pentoxide, does not burn 

 with a flame. Partial combustion, however, goes on, both carbon monoxide and 

 carbon dioxide being formed. 



2. If the charcoal is mixed with platinum black, and heated in the same way in 

 oxygen, about the same amount of charcoal is burnt. Carbon dioxide is, however, the 

 only product. 



3. When charcoal burns in oxygen, its combustion probably goes on in two stages. 

 It forms, first, carbon monoxide, and, if circumstances are favourable, this undergoes 

 further oxidation to the dioxide. 



4. Sulphur, boron, amorphous and ordinary phosphorus do not burn in dried 

 oxygen. Ordinary phosphorus does not even show luminosity, at any pressure, in 

 dried oxygen. 



5. Amorphous phosphorus is not converted into ordinary phosphorus when heated 

 in nitrogen to 278 C. This substance undergoes true combustion when heated to 

 260 in moist air or oxygen, without any previous change to the crystalline variety. 



6. Selenium, tellurium, arsenic, and antimony show no difference in their combus- 

 tion, whether the oxygen be moist or dry. 



I am indebted to Professor H. B. DIXON, F.R.S., for much valuable advice and 

 encouragement during the progress of this investigation. 



