300 EREMACAUSIS OR DECAY; 



izing agents on aloohcl ; b'lt it can scarcely be doubted, that the 

 formation of the last product, .he carbonic acid, does not take 

 place until all the hydrogen has been abstracted. 



The absorption of oxygen by drying oils certainly does not 

 depend upon the oxidation of their carbon ; for in raw walnut- 

 oil, for example, which was not free from mucilage and other 

 substances, only twenty-one volumes of carbonic acid were 

 formed for every 146 volumes of oxygen gas absorbed. 



It must be remembered, that combustion or oxidation at low 

 temperatures produces results quite similar to combustion at 

 high temperatures with limited access of air. The most 

 combustible element of a compound exposed to the action of 

 oxygen, must become oxidized first, for its superior combustibility 

 is caused by its being enabled to unite with oxygen at a tempera- 

 ture at which the other elements cannot enter into that combina- 

 tion ; this property having the same effect as a greater affinity. 



The combustibility of potassium is no measure of its affinity 

 for oxygen ; we have reason to believe that the attraction of 

 magnesium and aluminium for oxygen is greater than that of 

 potassium for the same element; but neither of those metals 

 oxidizes either in air or water at common temperatures, whilst 

 potassium decomposes water with great violence, and appropriates 

 its oxygen. 



Phosphorus and hydrogen combine with oxygen at ordinary 

 temperatures, the first in moist air, the second when in contact 

 with finely-divided platinum ; while charcoal requires a red heat 

 before it can enter into combination with oxygen. It is evident 

 that phosphorus and hydrogen are more combustible than char- 

 coal, that is, that their affinity for oxygen at common tempera- 

 tures is greater ; and this is not the less certain, because it is 

 found, that carbon in certain other conditions shows a much 

 greater affinity for oxygen than either of those substances. 



In putrefaction, the conditions are evidently present, under 

 which the superior affinity of carbon for oxygen comes into 

 play ; neither expansion, cohesion, nor the gaseous state, opposes 

 it, whilst in eremacausis all these restraints have to be over- 

 come. 



The evolution of carbonic acid, during the decay or erema- 



