Silicosis is here treated broadly. As most of the basic facts of the etiology, pathology, roentgenology and diagnosis of the disease have been presented in previous symposiums, these topics are covered by relatively brief yet adequate reviews. The importance of the degree and type of exposure and individual variation in response is discussed by Cummings. Gardner explains the pathologic process and the relation of tuberculosis to silicosis. Riddell gives a summary of the clinical appearances in simple silicosis and in silicosis complicated by tuberculosis, emphasizing the importance of the infectious process in the causation of symptoms. Pendergrass covers the subject of pulmonary anatomy in healthy and silicotic individuals, with particular attention to the x-ray appearances. There is a paper by Drinker on the technics and interpretation of dust counts and analyses.
This basic groundwork having been established, the symposium goes on to some special considerations. These include the problem of