18 MIASM, TRADITION AND. PREJUDICE 



wise men of the colony foretold that an epidemic 

 would witliout fail arise in consequence ; of course, 

 in those days it often did, but as we shall see, not from 

 the miasm but from causes now as clearly proven as the 

 law of gravitation. 



By the word " miasm " is implied an exhalation 

 or emanation from the soil, especially that of warm, 

 moist climates where there must always be an abund- 

 ance of decaying vegetable humus. In the name 

 " JNIalaria," or bad air, given to one of the largest groups 

 of miasmatic diseases, we see clearly what was implied 

 by miasm, and we can also understand why people were 

 so frightened at disturbing the soil. As tropical 

 countries must, owing to the luxuriance of vegetation, 

 have always a vast amount of fermenting vegetable 

 mattei', it was clear then that miasm came to be 

 regarded as the necessary evil of tropical countries, and 

 thus it came about that this nightmare theory of 

 disease was accepted as inevitable — it did not matter, 

 every one had to suffer alike from it ; they had to 

 get the " accUmdtisation fever," and then they were 

 " salted,'' and regarded as immune. Malaria and yellow 

 fever were the " diseases of the new-comers " ; after 

 an apprenticeship to the tropics they would recover. 

 The miasm was not peculiar to swamps or churchyards 

 or mud-banks ; it could equally well be incubated on 

 board ship, from bilge water, ballast, and certain forms 

 of cargo. I^earned works were written, in which the 

 kinds of cargo are specified which are most prone to 

 engender deadly miasm. 



So bad has this nightmare been at times, that 



