DUST AND DISEASE. 325 



what measures should be taken to stay an outbreak of 

 typhoid fever which had occurred in a large convent about 

 two miles from Bristol. The inmates were divided into 

 three distinct divisions ; the largest being a reformatory for 

 girls, who occupied the central block of the building. Into 

 this reformatory the fever was brought by a girl already 

 suffering from it, and who had contracted it in a sea-side 

 place more than twenty miles off. From this girl the dis- 

 ease spread until, at the date of my visit, more than fifty 

 girls were lying ill of it. From first to last the fever was 

 confined to the reformatory girls, and to persons in immedi- 

 ate attendance upon them. 



" Now, the facts as to the drinking-water were these : 



" 1. The water was proved by examination of the well, 

 and by chemical analysis, to be entirely free from sewage 

 contamination. 



" 2. The inmates of another large division of the con- 

 vent, who remained entirely free from fever, drank the same 

 water as the girls among whom fever was raging like a 

 plague. 



" 3. From the very time when disinfection was brought 

 to bear on the excreta the disease ceased to spread, although 

 the inmates of the infected division continued to drink the 

 same water as before. 



" Lastly, nothing has since been done to the well the 

 water remains what it was but no fever has occurred in 

 the convent since. 



" The evidence in both these cases is, as you see, of that 

 crucial, decisive order that admits of no reply. 



" They show, at least, that typhoid fever may do its 

 worst where drinking-water takes absolutely no part in the 

 distribution of the poison. 



" But if water be excluded, the air is the only other 

 possible vehicle by which a poison generated in the living 

 body can find its way back to other living bodies on a scale 



