

AMERICAN MUSEUM GUIDE LEAFLETS 
MOSQUITOES AND MALARIA 
Few diseases have, until recent times, seemed more mysterious 
than malaria. This malady was defined in Quain’s Standard 
Dictionary of Medicine as late as 1894 as “‘an earth-born poison, 
senerated in soils, the energies of which are not expended in the 
srowth and sustenance of healthy cultivated vegetation. By almost 
universal consent this poison is the cause of all the types of inter- 
mittent and remittent fevers, commonly called malarial, and of the 
degeneration of the blood and tissues resulting from long residence 
in places where this poison is generated.’ 
‘Malaria,’ the Encyclopedia continues, “‘has generally been 
said to be the product of heat, moisture and vegetable decomposition. 
The terms marsh miasm, and paludal fevers, long employed to 
distinguish the poison and the fevers to which it gives rise, mark the 
almost universal belief that the air of marshes alone is endowed with 
the power of generating them. That low, moist, and warm localities 
are generally noted as malarious, is indisputable. Marshes are not, 
as a rule, dangerous when abundantly covered with water; it is when 
the water level is lowered, and the saturated soil is exposed to the 
drying influence of a high temperature and the direct rays of the 
sun, that this poison is evolved in abundance. The production of 
malaria on a $reat scale in this way was seen in the district of 
Burdwan, in Bengal. ‘The soil is alluvial, but dry; and until within 
the last few years, Burdwan was more salubrius than the central or 
eastern districts of the lower Gangetic delta. The drainage of the 
district became obstructed by the silting up of its natural and artificial 
outlets, the result being a water-logged condition of the soil, the 
development of malaria, and an alarming increase in the death-rate. 
‘‘Malaria is, however, generated under conditions apparently 
widely different from the above. When the British Army under 
Wellington was operating in Estremadura, the country was so arid 
and dry for want of rain, that the rivers and small streams were 
reduced to mere lines of widely detached pools; yet it was assailed 
by a remittent fever of such a destructive malignity that, says 
Ferguson, who records the fact, ‘the enemy and all Europe believed 
that the British host was extirpated.’ ”’ 
Again “‘The disturbance of soil that has long been fallow is often 
followed, both in hot and temperate climates, by the evolution of 
malaria. A familiar example was the prevalence of intermittent 
fever in Paris during the fortifications of the same city, in the reign 
of Louis Philippe, and on a larger scale in different parts of France 
when the railways were in process of construction.” 
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