16 



Colonel David Bruce 



[Jan. 24, 



made out between it and the temperature or rainfall ; whether age 

 or sex render a person more liable ; whether occupation or social 

 position has any bearing on it ; whether a difference in sanitary con- 

 ditions has any effect, as, for example, do people living in small 

 villages without any proper system of water supply suffer more than 

 those living in towns supplied with pure water and a modern drainage 

 system? 



Now it is clearly impossible for me to go into all these points with 

 the time at my disposal, but I would like to bring before you a few 

 facts which bear on the problem we have before us. 



1899x0 1905. 1905. 



Fig. 1. 



-Chart of Incidence in 1899-1905, 

 AND 1905. 



Geographical Distrihution.—Yov example, it is interesting to know 

 that Malta fever is not confined to Malta, but occurs in most parts of 

 the world. 



Climatic Conditions.— Then again in regard to the effect of climate. 

 Malta is extremely hot and dusty in the summer, and correspondingly 

 cold and wet in winter. But, although the number of cases of 

 Malta fever do show an increase in summer, yet it is a disease which 

 is prevalent all the year round, one-third as many cases occurring 

 in the coldest and rainiest months, as in the hottest and dustiest. 



Another fact of importance, is that if we study the occurrence of 

 Malta fever in individual years, we are struck by its irregularity, a 

 number of cases appearing in December or February or other of the 

 cold and rainy months. 



