ADAPTATION TO CLIMATE. 399 



Thus miasmatic fevers are two hundred times more frequent north of 

 the equator than south of it, notwithstanding that there are extensive 

 regions in South America and Australia covered with standing water 

 and exposed to a burning sun. To this may be added that attacks of 

 fever are much less severe in the southern hemisphere. Only light 

 fevers prevail in the great lagoons of Corrientes ; how much more 

 dangerous are the fevers of the Pontine marshes, which are, neverthe- 

 less, very far from the equator ! A European can live with much 

 greater security against the contingency of fevers on the banks of the 

 Parana, in South America, than on the banks of the Garigliano, in 

 Italy. 



There has been no lack of attempts and theories to explain these 

 differences in localities that seem otherwise generally to stand under 

 the same physical relations, but none of them have been successful. 

 Yet it appears to be established that the greatest difficulties in the 

 way of Europeans becoming acclimated in places where their business 

 leads them to settle are due to the presence of swamp miasms. We 

 know that a variety of conditions must combine to produce such 

 miasms, and we know also that man is able to contend against them. 

 It is possible for man to open a campaign against Nature wherever he 

 goes, and to introduce conditions more favorable to his becoming 

 acclimated. But he has so far not been able to bring a whole country 

 immediately into a healthy condition ; only time seems to be com- 

 petent to bring such a work to completion, and, waiting its course, nu- 

 merous victims have to be offered up. 



The cultivation of the 'eucalyptus, a tree of remarkably quick 

 growth, appears to be one of the most effective means now available 

 for improving the condition of unhealthy localities. There are fre- 

 quently tracts of limited extent in the most sickly regions where the 

 process of acclimatization is relatively easy and secure. Such points 

 should always be chosen by new settlers. The contrary has generally 

 been the case. The beauty and fertility of the alluviums at the 

 mouths of rivers, with the conveniences they offer to trade, have gen- 

 erally been tempting enough to determine the location of the settle- 

 ment, regardless of its qualities with reference to health ; and towns 

 have been planted in such places in consideration of the apparent 

 value of the money-investment, but in complete forgetfulness of the 

 immense capital in human lives they are destined to swallow. — Trans- 

 lated for the Popular /Science Monthly from Das Ausland, 



