In 1905, Wainwright and Nichols2 offered strong support for the general belief that coal miners are less liable to pulmonary tuberculosis than other workers. From a study of the death certificates in Scranton, Pa., over a ten year period, they learned that pulmonary tuberculosis was the cause of death in 3.37 per cent of anthracite mine workers, as compared with 9.97 per cent for all other occupied males. They also cited the report of the United States census for 1900, which, classifying deaths according to occupations, showed that miners and quarrymen grouped together had second to the lowest death rate, 120.9 per hundred thousand. They believed on good grounds that, had quarrymen not been grouped with the miners, the rate for the latter would have been lower still.
Workers in some other dusty branches of industry, particularly those who inhale silica dust, are more than ordinarily susceptible to tuberculosis. The