V2i) lUSTOlUCAL SURVEY OF YELLOW FEVER 



were described as spontaneous. The cargo was blamed; 

 it might ha\e been green logs from Sierra Leone or 

 logwood from Honduras. But the majority of authori- 

 ties laid the blame to ballast, especially shingles, gravel, 

 mud or sand. The ballast was more often than not 

 wet when put in, or made so by the drippings from 

 the fresh-water tanks stored on board. The pestiferous 

 emanations from bilge water, mixed with the Ixillast 

 in all the forms in which it was encountered in the 

 days of sailing ships, were supposed to be the chief 

 cause, and very numerous examples of this are given 

 in the "Report on Yellow Fever," General Board of 

 Health, London, 1852. Quite recently Dr. Planning 

 of Barbados has reviewed a considerable number of 

 these instances to support the view which he shares, 

 and which, as we now see, were the views of the 

 school of miasms, fibrilifying influences, concatena- 

 tions, in the days before science had given us the true 

 explanation. The persistence of views like these to-day 

 shows in a very marked degree how hard it is to kill 

 tradition and superstition in our profession. The 

 explanation of all these so-called "spontaneous" out- 

 breaks on board ship has been admirably given by 

 Dr. Le Boeuf and by other American writers of the 

 past few years. A little thouglit Avill show at once 

 that yellow fever has almost disappeared from ships 

 since wooden vessels were replaced by iron steamships. 

 In the old days before a steam condensing plant, fresh 

 water was carried in numerous casks whicli were more 

 often than not leaky, the fresh water was taken in at 

 the ports of call, and no doubt contained innumerable 



