248 THE POPULAR SCIENCE MONTHLY 



mortality can also be noted, the death rate from acute lung diseases, in 

 districts with much smoke, being higher than in other industrial centers 

 with little smoke as textile districts. 



The physicians who worked in cooperation with the Smoke Investi- 

 gation of the Mellon Institute made valuable contributions to the ques- 

 tion of the relation of smoke to health. 6 



Dr. W. L. Holman, investigating the bacteriology of soot, arrived 

 at the following conclusions : 



1. Soot has a definite bactericidal action on bacteria, due either to 

 the absorption of moisture from the organisms or more probably to the 

 action of its contained germicidal acids and phenols. 



2. Soot, as it occurs in smoke, clouds, fogs and as a non-transparent 

 covering for our streets and houses, protects microorganisms from the 

 destructive action of sunlight. 



Dr. Oskar Klotz, attacking the subject from the viewpoint of a 

 pathologist, asserts that pulmonary anthracosis — a term applied to a 

 condition in which carbon particles of extraneous origin are deposited 

 in the lungs — is an urban disease and is proportionate to the smoke 

 content of the air. His examination of the lungs of adult individuals 

 resident in Pittsburgh shows that they have materially more carbon 

 deposit than the lungs of individuals resident in a lesser manufacturing 

 community. 



Dr. Samuel E. Haythorn, attempting to determine whether or not 

 excessive deposits of dust and coal pigment within the body tissues have 

 or have not any " real disease " significance, arrived at the conclusions : 



1. Moderate anthracosis in an otherwise normal lung is not in itself 

 detrimental to health. 



2. In tuberculosis, the anthracotic condition is either entirely passive 

 or is active in assisting healing, in that it aids in the localization of the 

 process through the obliteration of the lymph spaces. 



3. In the case of pneumonia, the effect of carbon deposits in the 

 lungs is quite different. The carbon blocks up the lymphatic spaces and 

 causes obliteration of the lymph channels. This results in serious in- 

 terference with the drainage system of the lungs and thus delays, if 

 it does not make impossible, the resolution of the pneumonic process. 

 An anthracotic lung has, therefore, less chance of recovery from pneu- 

 monia than a lung which has not undergone changes from the deposit 

 of carbon. 



Dr. William Charles White, from a study of the relation of the 

 mortality from tuberculosis and pneumonia to the smoke content of the 

 air, shows that, in Pittsburgh, pneumonia increases with the density of 

 smoke irrespective of the density of the population or of poverty. Tu- 



e Klotz, Oskar, and White, Wm. Chas., Bulletin No. 9, ' ' Papers on the In- 

 fluence of Smoke on Health," 1914. (Published by Mellon Institute.) 



