670 ANNUAL. KEPOET SMITHSONIAN INSTITUTION, 1910. 



especially by the specific treatment, in curing many cases. At pres- 

 ent, however, only a comparatively small percentage of cases share 

 this advantage, and for the cases not so treated we are unfortunately 

 convinced again and again that pulmonary tuberculosis maintains 

 the same deadly characters as formerly. Besides the decrease in con- 

 sumption had already been going on for several years before the new 

 methods of treatment had been widely disseminated. 



The decrease in consumption has often been ascribed to the dis- 

 covery of the tubercle bacillus. It has been said that by this, the 

 infectious character of the disease was proved and that, in conse- 

 quence of this, people became more cautious and avoided infection 

 as much as possible, while previously physicians did not admit the 

 infectiousness of consumption and the public at large followed them 

 in this as a matter of course. 



There is certainly much to be said for this argument. In any 

 case it is very striking that, with a few exceptions, the decrease in 

 consumption set in everywhere within a few years after that dis- 

 covery. Yet the exceptions prove at once that this new-born fear 

 of infection is not the only factor involved, although we must allow 

 to it ascertain influence which is by no means slight. 



German authors have frequently claimed that social regulations, 

 particularly insurance against illness, has had an effect upon the 

 decrease of tuberculosis. To a certain extent this is undoubtedly 

 true, particularly as regards present conditions in Germany; yet in 

 most other countriies, where such regulations have not yet been estab- 

 lished, the decrease has been just as great and has been going on at 

 the same time, so these regulations can not be with us the most 

 weightj^ cause. 



It would take me too long to enumerate and discuss all the attempts 

 at explanation that have been made, and I will therefore confine 

 myself in conclusion to those investigations of this question which 

 appear to me to be of the most importance. These investigations 

 were suggested by the striking fact that the death rate from tuber- 

 culosis shows gi^eat differences in the three countries belonging to 

 Great Britain. In England and Scotland it is decreasing; in Ire- 

 land, on the contrary, it is slowly but evidently increasing. News- 

 holme, the well-known medical statistician, has endeavored to find 

 the prime cause of this. With the greatest thoroughness he has ex- 

 amined all the factors in the question, chiefly lodging, food, condi- 

 tions of service, care of the sick, emigration, and has finally become 

 convinced that for Ireland the method of caring for the sick is the 

 determining factor. Wliile in England and Scotland phthisical 

 charity patients are committed to isolated institutions, in Ireland 

 they are supported without being required to place themselves in 

 an institution ; they therefore remain in their own lodgings and con- 



