182 BOAED OF AGEICULTUEE. [Pub. Doc. 



found in the air ; they are largely met with in hospitals, 

 houses and stables, wherever the air is impure, and in a 

 lesser degree they exist everywhere. We can filter them 

 from the air, and can also destroy them by the action of 

 chemical agents. On this process of filtration and disinfec- 

 tion of organic particles is founded the basis of antiseptic 

 surgery. 



Among these organized particles are also others, which 

 form a distinct group. They are characterized as being the 

 materies morbi, or disease-producing bacteria ; such, for in- 

 stance, are the poisons of pleuro-pneumonia, tuberculosis, 

 sheep-pox, cattle-plague, influenza, and probably anthrax 

 and glanders. That particles of disease-producing matter 

 can be conveyed by the air is well known. Epithelial scales 

 and pus-cells have been found in the air of hospitals, and in 

 those devoted to the treatment of skin diseases actual dis- 

 ease-producing fungi have been found. 



When particles exist in the air surrounding diseased ani- 

 mals, it is only rational to believe that in the case of in- 

 fectious diseases they may be the means of conveying the 

 specific poison. 



Various forms of bacteria have been detected in the air ; 

 putrefactive bacteria are always present ; those of anthrax, 

 tuberculosis and glande'rs are probably present under certain 

 conditions, — particularly those of tuberculosis. 



The organic matter found in air vitiated by respiration 

 and transpiration is made up of cast-off epithelium from the 

 mouth, air passages and skin ; organic vapors from the lungs 

 and skin, whose constitution is imperfectly known ; fasces, 

 in fine division ; and vapors derived from the decomposition 

 of materials from the intestinal and urinary passages. This 

 organic matter is accompanied by carbonic acid gas and 

 watery vapor. Regarding the latter, the cutaneous and 

 pulmonary transpiration from a horse, whilst in the stable, 

 is equal to about two gallons of water in twenty-four hours ; 

 for the ox it is about one and one-quarter gallons. The 

 vapor from the skin contains organic matter and carbonic 

 acid. 



It is this organic matter found in buildings which 

 holds such an important place in the hygiene of air. We 



