176 APPLIED BACTERIOLOGY 



part of the year is very dry, and becomes converted intc 

 dust. All excreta, whether from sick or healthy persons, 

 are buried in the ground according to the shallow system 

 and the soil is thus converted into a nursery for the growth 

 of the bacilli. Since dust-storms are of very commor 

 occurrence, especially in hot and dry weather, it is not 

 very difficult to understand how columns of fine dust 

 whirl across the country, loaded with fsecal debris, and. in 

 time of epidemics with pathogenic organisms. Thus dust- 

 storms become a fertile means of spreading the disease, 

 since the typhoid bacillus has considerable vitality ; wells 

 and water-supplies at distant stations become contaminated 

 and the disease is thus spread far and wide. One means 

 of preventing some of the epidemics of typhoid fever now 

 so prevalent in India would be to insist that all excreta 

 from typhoid cases should be disinfected or burnt. 



In connection with the above information, which was 

 supplied to us by Surgeon-Lieutenant Birdwood, of the 

 Indian Medical Service, it is interesting to compare a 

 report by Dr. H. Henrot, of Kheims {Lancet, February 1, 

 1896), respecting an outbreak of typhoid which occurred 

 amongst two regiments of cavalry quartered in the above 

 town during some manoeuvres. The men rode over some 

 land which had been recently manured with night-soil, 

 and the weather being very dry, much dust was produced, 

 which was of necessity both inspired and swallowed by the 

 troopers. Attention was also directed to the bad smell 

 which was prevalent at the time. Inquiry was directed as 

 to whether the outbreak could be attributed to the water- 

 supply, but this did not appear to be the fault, as civilians 

 using the same wells were not attacked. This case seems 

 to give additional probability to the theory advanced by 

 Dr. Birdwood, which was communicated to us some weeks 

 before the publication of Dr. Henrot's report. 



