.Dr. Mac Culloch on Malaria on Ship-board, 45 



tions and expenses arising from which will not easily be for- 

 gotten by those who have suffered from them. The reverse 

 mistake, that of treating a contagious fever as if it was not 

 contagious, has scarcely, perhaps, occurred much in our own 

 country, because our errors are of the reverse nature : but 

 while this would soon take place, should the sect, which 

 admits of no contagious fever, make progress, it is apparent 

 that the consequences would be most pernicious, since they 

 would be the propagation of the disease : the same events, if 

 on a smaller scale, which occurred to so terrific an extent at 

 Gibraltar. How this affects the case of ships, I shall defer 

 till I speak on this specific subject, that I may consolidate 

 what appertains to that most important question, and the 

 main object of this paper, into the most compact possible 

 form. But there is one serious consequence of this pre- 

 vailing error, viz., that of confounding marsh fever with 

 typhus ; which^ if less obviously apparent, I should be unpar- 

 donable in passing by, since it is, perhaps, equal in bad results 

 to all else. If the vulgar, and, above all, the shallow and self- 

 elected, critics, with which the popular literature of the hour 

 abounds, suppose that fevers arise from no causes, or drop down 

 from the clouds under magic or mysteries unappreciable by 

 philosophy, it is not necessary to answer this class of modern 

 philosophers. That effects arise from causes is no very pro- 

 found discovery ; and that effects may be regulated by regu- 

 lating their causes, is not much more difficult to comprehend. 

 Fevers, it is to be presumed, have their causes, like all other 

 efiects ; and to know these, is to have made the first step, at 

 least, in the management of the diseases in question. To 

 command them, is to command the effect ; to be able to 

 modify them, is to modify it ; to destroy them, or to intercept 

 their action, is prevention ; and prevention is health, as far 

 as this disease, extensive in quantity and in evil, is concerned. 

 Let, then, an exact, accurate, and invariable distinction be 

 drawn between contagious and non-contagious fevers ; typhus 

 and marsh fevers : and if there are but these two classes or 

 species, as I hope to show still further than I have already 

 done, we have acquired a command, to a certain extent, over the 

 causes — while this command is prevention. How to prevent 



