THE PHAGOCYTOSIS OF SOLID PARTICLES. 

 III. Carbon and Quartz. 



By WALLACE O. FENN. 

 {From the Laboratory of Applied Physiology, Harvard Medical School, Boston.) 



(Received for publication, January 15, 1921.) 



It has been shown by Haldane (1) and by Mavrogordato (2) that 

 silicious dust when inhaled tends to remain in the lungs, causing 

 phthisis. Coal dust, on the other hand, tends to move out of the 

 lungs and is, therefore, harmless. The different behavior of silicious 

 and carbonaceous dusts in the lungs is also the cause of the abnor- 

 mally high mortahty from tuberculosis among siHcious miners and 

 the abnormally low mortahty among coal miners (3). Without going 

 into a discussion of the mechanism of dust removal from the lungs, 

 it is sufficient to state that the first step appears to be always the 

 ingestion of the dust particles by phagocytic cells in the alveoli. 

 It seemed probable, therefore, that a study of the phagocytosis of 

 carbonaceous and silicious particles would show that the former are 

 ingested more readily than the latter, in agreement with the cUnical 

 facts, and might throw some light on the cause of this difference. 

 This was found to be true. 



It became at once evident, in undertaking a comparison between 

 the rates of phagocytosis of carbon and quartz particles, that the 

 usual method of incubating them together with the leucocytes in a 

 common suspension might yield nothing more than a comparison of 

 the relative chances of collision of the two kinds of particles with the 

 leucocytes. It has, in fact, been shown in two preceding papers on 

 the phagocytosis of quartz (4) and carbon (5) particles that the 

 more rapid ingestion of large particles by leucocytes compared to 

 small ones can be accounted for quantitatively by the fact that a 

 large particle moves faster when stirred up in a suspension with 

 leucocytes, and therefore comes into coUision with more cells in a 

 given time. In this paper the same methods will be appHed to a 



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