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that appeals to the senses. Many persons are satisfied with a very simple 

 explanation, and frequently a name suffices. The term '-malaria" ety- 

 mologically means "bad air," and was applied to the disease in olden 

 times when bad air or a "miasm" was supposed to cause it. 



Now what is malaria? we may aslc. What is its cause? How does it 

 get into the body? 



Diseases due to a specitic cause, to a living organism, spread about 

 over the face of the earth just as we see animals and plants spread. 

 Many with originally restricted habitats have in the course of time 

 attained a world-wide distribution. Some diseases, natives of warm 

 climates, periodically leave their natural boundaries, as yellow fever or 

 cholera, flourish for a short time and then disappear utterly. If a new 

 disease appears in a country and tlie conditions for its existence are 

 favorable, then the disease remains and is called endemic. The cold of 

 our winters has a destructive effect on many diseases and a retarding 

 influence on others. Some flourish only during the warm months of the 

 year. 



Tlie date when a new disease lirst appeared in a country, or rather 

 an old disease in a new country, is accurately laiown in many instances, 

 and the gradual spread after its introduction has l)eeu carefully followed 

 in some cases. Leprosy, for instance, now so common in the' Sandwicli 

 Islands, was brought in by the Chinese in 1840. 



Malarial fever liad a restricted habitat in former times and has gradu- 

 ally spread and still does spread to places where it had never been seen 

 before. Its appearance and spread in the Island of Mauritius in compara- 

 tively recent years was attended with a frightful loss of life. It was 

 brouglit into the island in 1S6G by some side sailors, and an epidemic 

 followed; in the year 1867. 32,000 out of a population of 310.000 died of 

 malaria. In some of the lowly situated districts more than one-flfth of 

 the population perished from fever alone. 



The original home of malaria is unknown. Many of tlie islands of 

 the sea are still free from it. All other conditions may be favorable, but 

 unless tlie active cause is introduced tlie disease never appears in a 

 country where it had never been knoAvn to occur. 



It is now about tAventy years since Laverau, a French military sur- 

 geon, then stationed in Algiers, discovered and first described tlie active 

 cause of malaria. This discovery has been verified again and again 

 and is now universally recognized as the cause. It is a minute form 



