284 Dr. H. T. Bulstrode [May 15, 



observe as regards this matter that Dr. Tatham, the Superintendent 

 of Statistics, regards this fall as in very large part a real one. 



It is obvious that this fall cannot have been due to the conscious 

 avoidance of infection, seeing that the fall in this and certain other 

 countries commenced long before the discovery of the bacillus, and 

 the disease was not, in so far as practice was concerned, regarded as 

 communicable until recently ; and, similarly, it cannot have been 

 due, as Professor Koch thought in 1901, to the special institutions 

 for the disease, seeing that they were, until this century, far too few 

 to have exercised any appreciable effect upon the death-rate of the 

 country as a whole. 



Possibly the disease, while actually as prevalent as formerly, may 

 be less fatal ; and hence, fewer deaths in relation to the population 

 may occur, a fact, if it be one, which may perhaps be attributed to 

 earlier recognition of the disease and more rational treatment. 



Again, as others have claimed, segregation in poor law and other 

 institutions may have exercised an influence, as also may the decline 

 of certain diseases which are believed to predispose to phthisis. 



The general opinion amongst epidemiologists who have studied 

 the tuberculosis problem is that the causes are multiple, and mainly 

 social — that is to say, that consumption is very largely a social 

 malady, associated with conditions which are found, for the most 

 part, amongst the poor. Such conditions comprise insufficiency of 

 food, overcrowding, absence of light, ventilation and cleanhness, 

 overwork, over-indulgence in alcohol, dampness of soil, and other 

 obviously unwholesome factors. 



The evidence of such causation is based largely upon statistical 

 evidence, some of which is not very reliable, but it may be said 

 generally that the disease is found to be associated, although not 

 entirely, with the conditions which may be summed up under the 

 term " poverty," a term which obviously embraces a large number of 

 the separate factors enumerated above. 



It would be possible to exhibit numerous charts illustrating the 

 association of phthisis with overcrowding and other factors, but I 

 must content myself Avith exhibiting a chart indicating the apparent 

 parallelism between poverty and pulmonary tuberculosis in the three 

 divisions of the United Kingdom. 



It will be seen that the thick black curve represents the behaviour 

 of total pauperism per 1000 of the population in each division of the 

 Kingdom, and that the dotted curve represents the death-rate per 

 10,000 of the population from phthisis, or pulmonary tuberculosis. 

 The lowest curve in each instance relates to indoor pauperism. 



In England and in Scotland a declining pauperism is, generally 

 speaking, associated with a declining death-rate from phthisis ; in 

 Ireland arising total pauperism with a high and presumably rising 

 phthisis death-rate. It will be noted that in England and Scotland 

 the curve for indoor pauperism is low, while in Ireland it is high. 



