40 BACTERIA IN DAILY LIFE 



was thrown over and upon the cliffs, this being 

 the usual method of disposing of sewage. Ample 

 opportunity was thus given for its desiccation 

 and subsequent distribution as dust. That this 

 typhoidal matter did subsequently become pul- 

 verised and spread the infection Dr. Mewius has 

 no doubt, the germs having been conveyed to 

 the open rain-water cisterns which constitute the 

 water-supply of the majority of the inhabitants. 

 His theory is again supported by the coincidence 

 between the prevailing direction of the wind and 

 the quarter where the outbreak occurred. 



That diphtheria germs can remain for a long 

 time in a living and, what is more, virulent con- 

 dition in dust has been clearly demonstrated 

 by Germano, amongst other investigators, this 

 organism being specially endowed with the 

 capacity for resisting the, to other microbes, 

 lethal effect of getting dried up. 



Bacteria, however, survive this desiccation pro- 

 cess much better when they are herded together 

 in large numbers than when they have to face 

 such untoward conditions as isolated individuals. 

 TJiis has been well illustrated in the case of 

 diphtheria bacilli, and the difference in their 

 powers of endurance under these respective con- 

 ditions is very striking. Thus when a few only 

 were exposed to a very dry atmosphere on 



