NO. I AIR AND TUBERCULOSIS— HINSDALE 9 



vegetable matter in process of decay and by uniting with the gases 

 produced by their decomposition. It can, therefore, be found in con- 

 siderable amounts where the air is particularly pure. This amount 

 rarely exceeds one part in 10,000. " There is somewhat more ozone 

 on mountains than on plains and most of all near the sea. Water is 

 said by Carius to absorb 0.8 of its volume of ozone." ^ 



This statement by Mr. Russell seems to us extraordinary in view 

 of the minute quantity contained in the atmosphere and apparently 

 needs confirmation, especially in view of Russell's next statement 

 that a great excess of ozone is destructive to life, and oxygen con- 

 taining one two-hundred and fortieth part of ozone is rapidly fatal, 

 and further, that even the ordinary quantity has bad effects in 

 exacerbating bronchitis and bronchial colds, and some other affec- 

 tions of the lungs. 



Ozone is not found in the streets of large towns or usually in 

 inhabited rooms, but in very large, well ventilated rooms it is some- 

 times, though rarely, detected. According to Russell it may be 

 formed on the slow oxidation of phosphorus and of essential oils 

 in the presence of moisture. When produced by electric discharges 

 its pungency of odor is said to make it easily perceptible when pres- 

 ent only to the extent of one volume in 2,500,000 volumes of air 

 and the smell may sometimes be noticed on the sea beach. 



Since the discovery of ozone by Schonbein, not much has been 

 learned about the actual origin of this allotropic form of oxygen. 

 Its presence in and near forests and living plants has undoubtedly 

 supported the popular view that the air of the forests is particularly 

 healthful and that living plants in our apartments are likewise bene- 

 ficial.' 



The existence of hydrogen peroxide in air was first established by Meissner 

 in 1863, but we have no knowledge of the proportion in which it is present. 

 All information as to its relative distribution is obtained from determinations 

 of its amount in rain water and snow. The proportion seems to vary, like that 

 of ozone, with the seasons of the year and with the temperature of the air. 

 It is not improbable that the amount of hydrogen peroxide in air is greater 

 than that of ozone, and it is possible that many so-called ozone manifestations 

 are in reality due to peroxide of hydrogen. Watts' Dictionary of Chemistry. 



"^ Francis A. R. Russell : The Atmosphere in Relation to Human Life and 

 Health, Smithsonian Miscellaneous Collections, Vol. 39 (Publication No. 

 1072), 148 p., Washington, 1896. 



'^ See J. M. Anders : House Plants as Sanitary Agents, Lippincott & Co., 

 1887. 



