CHEMISTKY OF PUTREFACTION. 263 



It is by this means that that accumulation of 

 particles of every kind, which would otherwise 

 load the air, and interfere to a serious extent 

 with its purity and functions, is obviated. But, 

 particularly, these principles appear to have 

 the power to destroy those noxious organic 

 particles which are evolved in certain diseases. 

 The fresh air is the worst enemy of putrid 

 fevers; oxygen, whether derived from this ele- 

 ment in the air or from the decomposition of 

 ozone, combines with the fetid exhalations, 

 neutralizes their effects, and reduces them to 

 powerless and innocuous forms of matter. 

 Thus oxygen, in a variety of ways, assists to 

 preserve the purity of the air, and its freedom 

 from accidental ingredients for any length of 

 time. It sets up putrefactive processes, when 

 life has ceased, both in vegetable and animal 

 bodies ; these are the first powers of destruc- 

 tion, which are to be succeeded by others, and 

 these again by others, until all is destroyed. 

 It is on this account that the complete exclu- 

 sion of air prevents the putrefactive process 

 from commencing. Meat is preserved for 

 years untainted in close vessels. 



When decomposition sets in, the tissues of 

 the animal frame become resolved into gaseous 

 and watery elements. The atmosphere seizes 

 again upon these, and takes quickly from them 



