THE CAUSATION OF DISEASE. 2 4 1 



traceable to confinement, pure and simple, and which are 

 experienced, even though every hygienic precaution be taken 

 to render the air breathed pure and healthy, there are many 

 occupations, both indoor and out, which necessitate the breath- 

 ing-in of irritating particles, and there are a host of others 

 which injure in ways innumerable. Such E's are probably 

 all necessarily fatal. 



This may at first sight appear to be a gross exaggeration ; 

 we must, however, bear in mind that there are several circum- 

 stances tending to mitigate and to obscure the fatal results. 

 In the first place the injurious occupation is in many instances 

 not followed until the individual has nearly arrived at, or has 

 actually reached, maturity ; and, some little time being re- 

 quired for the E to work its injurious effect, he may mean- 

 while rear healthy offspring, more especially if he live in the 

 country, where the children can have abundant outdoor exer- 

 cise. Seeing that legislation cannot render all occupations 

 strictly healthy, we ought at least to see to it that as far as 

 possible boys and girls be not allowed to follow injurious 

 occupations. It is during the growing period of life that 

 a mal-E works its greatest evil, for it then interferes with 

 proper body-growth, and leads to rapid physical deterioration. 

 If possible, then, we should prevent a young growing indivi- 

 dual from following an injurious calling. Such a prohibition 

 is, however, often impracticable, for most of these very occu- 

 pations require early apprenticeship, sometimes, indeed, com- 

 mencing in extreme youth. 



A second circumstance tending to prevent this family extinc- 

 tion is the very obvious one that all the members of the same 

 family rarely follow the same injurious occupation for several 

 successive generations, and if only a few of the children engage 

 in healthy outdoor pursuits, the family may thus continue its 

 existence. 



In large towns, however, most of the children, although 

 not often all following the same occupation, nevertheless 

 very generally follow some other injurious calling, or are from 

 the beginning of life brought up under unfavourable condi- 

 tions ; wmerefore, as we shall presently see, a large town con- 

 stitutes in itself a necessarily fatal form of E. But, leaving 



