AND ENVIRONMENT 2f) 



Examine the same phenomenon apart from population 

 totals, namely, by considering whether fewer deaths now 

 occur from phthisis relative to all deaths. See Fig. VII, 

 p. 30. During our first period we see a very sensible 

 drop in the relative phthisis death-rate; then with the 

 sanitation period comes the accelerated fall, and then in 

 our last period of greatest activity — in the last 15 years, 

 when we are said to know all about phthisis, and when we 

 are told that a sufficient number of millions have only to be 

 spent in a certain manner in order to abolish it altogether 

 — we find — what ? That the phthisis death-rate relative to 

 all deaths has begun to rise in males, and is almost con- 

 stant in females, or indeed, since 1900, has also begun 

 to rise. 



Now, Ladies and Gentlemen, various explanations have 

 been offered to me of the source of this retarded fall in 

 the phthisis death-rate. The first I give you is certainly 

 ingenious, and may have played some part in the matter. 

 Formerly, the constitutional factor was recognized by 

 laymen and medical men as an important factor, and 

 marriages with or between phthisical stocks were 

 everywhere discouraged. Then came the swing of 

 the pendulum : the bacillus was the only thing to be 

 regarded, and it did not Hke fresh air. The only thing 

 needful was to keep bedroom windows open, and marital 

 selection was of no importance. The result, according 

 to this suggestion, has been increased panmixia and a 

 production of stocks constitutionally liable to lethal 

 tuberculosis in larger numbers. 



A second explanation has been given me by a medical 

 friend. His view is that the increase is due to better 

 diagnosis of lethal tuberculosis in our last period of 

 improved medical knowledge. The question is whether 

 the average general practitioner, who gives the great 



