294 THE CAUSATION OF DISEASE. 



of E in each of these cases is manifested by the special and 

 peculiar way in which these several occupations mould the 

 individual. Who cannot discriminate between a soldier, a 

 sailor, or a butcher, and that not only by the outward mould- 

 ing of the body, but, if opportunity for observation offers, by 

 the inward and more subtle moulding of the mind ? Now if 

 we take E to represent the entire environment of any one of 

 these occupations, and if the inter-action of S and this E result 

 in health, the E of this occupation may be regarded as normal. 

 A large number of occupations in civilized societies are neces- 

 sarily injurious, and nothing could make them otherwise ; 

 indeed, it maybe said of very many (I believe, of the majority), 

 that they are necessarily fatal, if not always to the first gene- 

 ration, yet certainly to the second or third ; and it would be 

 well for us boldly to acknowledge the grim fact. Neglect- 

 ing, however, those occupations in which S and E cannot, by 

 any possibility, work healthily, and considering only such as are 

 compatible with perfect health, we shall still find among indi- 

 viduals, who yet would be accounted healthy, a considerable 

 difference as regards their normality to their respective E's. This 

 occupation might especially suit one individual ; that, another. 

 An individual leading, as a brain worker, a comparatively 

 sedentary life, attains, let us suppose, a ripe old age ; but it 

 is very possible that early death might have resulted if he had 

 followed the laborious occupation of a navvy ; and on the 

 other hand, there may be many an old and healthy workman 

 who would have died early had a sedentary, scholastic career 

 fallen to his lot. The workman who attains a ripe old age 

 might, for instance, under an inactive mode of life, develop 

 kidney disease, while the brain-worker might suffer from 

 aneurism or hernia had his life been one of muscular labour. 

 Of course, there are many who, provided they observe the 

 ordinary laws of hygiene, would reach old age in any occupa- 

 tion, but it is none the less true that individuals differ greatly 

 in their power of living healthily in different employments, 

 even though they studiously regulate their lives according to 

 those laws. 



What is true of the physical side is true also of the mental 

 side of man. Many miss their vocation in life, and un- 



