342 POPULAR SCIENCE MONTHLY. 



efforts on tlie destruction of the bacilli is the only, or even the 

 best, way of exterminating the disease. Few diseases prevail so 

 generally throughout the world as tuberculosis. No zone is ex- 

 empt from its ravages, and it has prevailed from the earliest times. 

 Its victims constitute seventeen per cent of all deaths, and nearly 

 five thousand succumbed to it in New York city in 1894. It affects 

 also the lower animals, especially the cow, which is so important 

 a source of food supply. Many persons are fatally affected by it 

 long before they are obliged to leave their occupations, or even to 

 consult a physician. The methods which have proved so success- 

 ful with the acute infectious diseases can hardly be applied effec- 

 tually with such a disease as this, and the attempt to deal with it 

 solely on this line may even prove mischievous sometimes by fos- 

 tering a belief that exemption can be secured simply by shunning 

 the sick. Should such a view prevail generally, unnecessarily 

 severe and even cruel measures would sometimes be adopted by 

 the timid and ignorant. Not long ago a writer proposed that all 

 cases be segregated and quarantined in a valley in New Mexico, 

 where climatic conditions were favorable to recovery. Govern- 

 ment aid being given the impecunious, and a leading New York 

 daily commented favorably on the proposition. 



The importance, then, of correct views on this subject can 

 scarcely be overestimated. We have seen that, though the dis- 

 ease is undoubtedly communicable, it does not prove so under all 

 circumstances. It is a question if any one of sound heredity and 

 good health has ever developed it simply from living with a con- 

 sumptive in ordinarily good hygienic surroundings. It is gener- 

 ally admitted that predisposing conditions can always be found. 

 The germs of this disease can not obtain a foothold until the 

 resistive powers of the tissues have been reduced. There must 

 be not only the seed but the soil. This impaired power of resist- 

 ance may be the result of heredity, and this influence in the 

 causation of disease is seldom shown to better advantage than in 

 the history of consumption. There have been instances in which 

 a single case introduced into a long and sound ancestry has viti- 

 ated the stock forever. How unfortunate that such matters are 

 so little considered in marrying and giving in marriage ! It is 

 not that the disease is inherited, but the vulnerable tissues, the 

 feeble resistive powers, render the offspring an easy prey to the 

 ubiquitous bacillus. This weakness often shows itself by a tend- 

 ency to become ill from slight causes, a sickliness, not by any 

 means to be confounded with merely a lack of robustness or 

 strength. One organ or part of the body, frequently the mucous 

 membrane, is usually more prone to become affected, and the 

 beginning of the disease can often be traced to an attack of some 

 slight ailment. Not only the children of consumptive parents 



