IMMUNITY OF THE COAL-MINEE. 29 



In every case of so-called " miner's-phthisis " which I have seen, 

 there has been a distinct family-history of the disease. 



A man predisposed hereditarily to consumption, developes it, 

 not more readily as a coal-miner, than in any other employment. 

 The black expectoration seen in miner's consumption, proves no 

 more than that the coal-dust has reached the lungs certainly not 

 that it is the cause of the disease. Coal-dust or, to call it by its 

 proper name carbon, from its highly antiseptic properties, acts 

 as an excellent protective to the pulmonary organs. The figures 

 on the table very strikingly corroborate this view. You will 

 notice, perhaps with surprise, that among twelve hundred sick 

 miners, only one case of consumption occurs ! 



THE EFFECTS OF ANIMAL-DUST. 



Animal-dust is evolved in the processes of brush-making and 

 hair-dressing, in the operations carried on by the skinner, tanner, 

 and hatter ; and in those of the button, harness, and clothmakers. 



I allude, of course, to these occupations as they are carried on 

 upon a great scale in large manufacturing centres, where there 

 is machinery, and where workmen are massed together in large 

 bodies under one roof. 



In such a city as this, with its limited and well-regulated in- 

 dustries, it is difficult to one,- not directly conversant with their 

 details, to realise what such operations really imply. When, 

 for instance, I name hair-dressing as one of the occupations of 

 the present group, the term is intended to include all the pro- 

 cesses connected with the preparation of hair for its artistic and 

 commercial uses. So that the name, in this connection, suggests 

 little, if anything, in common with the comparatively healthy 

 avocation of the perfumer and hair-dresser familiar to us. I 

 may as well remark here, to prevent misunderstanding, that this 

 statement applies generally to all the occupations now under con- 

 sideration. We have already observed that the excessive 

 mortality prevailing among the cotton, flax, and hemp-weavers, 

 has its origin chiefly in the irritation induced by the contact of 

 shreds of these substances with the lungs. 



We have all experienced, I suppose, the trouble which a 



