758 THE POPULAR SCIENCE MONTHLY. 



officers had wine." Thus in the drinking-water no difference obtained. 

 Ballast might have been a vehicle of infection, and for this purpose 

 sea-sand and shingles, and other material, were taken from the shore. 

 But I have been informed that "on the Britannia, as well as other 

 English men-of-war, the ballast consisted only of so-called jaig-iron, 

 four-sided pieces, which were wedged together in the lowest part of 

 the vessel, and never touched." We have yet to consider the different 

 habits of the men and the officers while on shore before the outbreak of 

 the epidemic. On this matter my informant writes : " The sufferers, 

 not only of the Britannia, but of the rest of the ships of the fleet, had 

 frequent communication by daily visits with the shore as we lay off 

 Varna, and the crew without doubt betook themselves to those poisonous 

 liquors, and still worse places of pleasure, which had sprung up on shore 

 like mushrooms." It may be understood that the company of one ship 

 would, like men of the same regiment, visit places of pleasure together 

 and imbibe the same drink, and so it might happen that a particular 

 crew visited a certain place where cholera prevailed, while other crews 

 might have unconsciously kept clear of the places from which it is sup- 

 posed cholera was taken. It remains doubtful whether the infection 

 was derived through the air, water, or food. If these circumstances 

 be viewed in an unprejudiced light, it will be seen that local condi- 

 tions may account for the infection and spread of cholera on board 

 ships. On emigrant-ships the matter can not be otherwise, and it is 

 necessary, therefore, to inquire into the previous history of those who 

 were taken ill on board. I have shown that the eleven cases of cholera 

 which occurred on the Westphalia, bound for New York from Ham- 

 burg, came exclusively from two German families, and that an epi- 

 demic as vast as that which befell the crew of the Britannia might be 

 explained, if we supposed that a majority of it came from the same 

 district, or were placed under the same conditions as the two German 

 families prior to their going on board. The exceptional outbreaks on 

 emigrant-ships prove that such an occurrence is possible. That the 

 Britannia, as a ship, was not a place of infection, is shown by the free- 

 dom from cholera enjoyed by the sixty officers. These points may 

 possibly be cleared up by the appointment of a commission to inquire 

 into the presence and etiological factors of cholera on board ship during 

 epidemics of cholera. Koch has spoken of the occurrence of cholera on 

 ships, and has attempted to reconcile matters on the basis of his doc- 

 trines of contagion. He has studied those ships which ply between 

 North America and Calcutta. This line has not escaped my attention, 

 and I have stated the main facts in my paper on " Cholera in India," 

 1871. Koch comes to the same conclusions as I did. Of two hundred 

 and twenty-two vessels which made the voyage during ten years, cases 

 of cholera only appeared on thirty-three ships, although they started 

 from a district where cholera is endemic. It appeared to Koch only 

 to be of importance, that cases of cholera continued to occur more than 



