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Page:Popular Science Monthly Volume 24.djvu/718

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THE POPULAR SCIENCE MONTHLY.

CORRESPONDENCE.
 

MOSQUITOES AND MALARIA.

Messrs. Editors:

"With shall decide when doctors disagree?" Not long since was put forth the theory that the "bite" of the mosquito is a genuine antidote for malaria, and one of the arguments used to sustain the assertion was that Nature provides remedies alongside all forms of disease, and that, wherever malaria abounded, mosquitoes did much more abound, and were busily engaged, to the best of their ability, in injecting a tonic under the skin of poor ague-stricken humanity, which would effectually cure the disease if the humane work of the winged surgeons was not interfered with; and now comes Professor King, in the September number of your journal, with the startling claim that the mosquito is the very cause of malarial diseases!—and the problem, Shall we encourage or kill the insect? is still unsolved.

Having had some experience with these much-denounced insects in the woods and by the inland lakes in the northern part of the Lower Peninsula of Michigan, and on and beside the lagoons of Southern Florida and even in the hotel sleeping-rooms in many parts of the land, I feel compelled to differ with Professor King in some of his alleged "facts," and I fear some of my statements will at least throw a doubt over the supposed "established facts" of the professor.

The professor argues that a locality abounds in mosquitoes, and that malaria is found to prevail in the same locality, and therefore it is quite probable that the malarial diseases there are produced by the mosquitoes.

Suppose we assume that it is quite as probable that the condition of heat, moisture, soiL, and vegetation, merely makes the locality a spot favorable to the generation of both mosquitoes and malaria, without any connecting relation one with the other. Suppose, again, we find localities where the mosquito, during a part of the year, is, by the power of numbers and fierceness of attack, almost king of the woods, and yet there is no malaria to be feared or found.

I have been in several localities on Indian River and Mosquito Lagoon, on the south-east coast of Florida, where I would not like to have 1 been on the outside of my netting, under the little shelter-cabin of our sail-boat, but I have never seen more numerous and, in localities, more voracious mosquitoes than in our northern forests in Michigan. The efforts on the part of these insects to produce malarial disease, in some form, if

this is their mission, were never more persistent than there. I have from the best authority the fact that it is no very uncommon thing for hardy woodsmen, in the spring months, to be driven from their work in the forest by the mosquitoes and black flies; but the general rule is, in the milder attacks, for the choppers to become so accustomed to the mosquitoes, day and night, as to pay little attention to them, they "let 'em bite," only disturbing them when, by an unusual attack, they overstep the reasonable demands for blood. Many of these men have come under my personal observation during a residence of from two to six weeks each year for seven years at our summer resort on Grand Lake, three miles back from Lake Huron. As I knew them to be working day after day in the low cedar lands, often in wet swamps, and drinking the swamp water where they could find a pool under some old moss-bed, and often sleeping in rude log or board shanties in the same locality, I have often asked them if they did not get the ague, or "chills" and fever. The answer was always, "Never." I have seen many little children, from the babe up, with naked legs, feet, arms, and no head-covering but the hair, absolutely covered more with mosquito-bites than garments, all through the season, but I have never known a case of malarial disease in any form among them. In view of these observations, I must conclude the case is hardly made out that mosquitoes produce malarial diseases, although in many localities the two are co-existent.

The professor says it is a fact of common observation that mosquitoes are more numerous in the late summer months. I am not sure of other localities, but in Upper Michigan, at our resort, and all through Northern Michigan, the fact is exactly the reverse. We usually require nettings during July. About the 1st of August the mosquitoes begin to disappear, and we can sleep without nettings; but, during May, June, and July, if they created malarial diseases, there would be lively shakes among the settlers, where malarial diseases are now unknown, or of extremely rare occurrence.

I do not know but the sea-coast mosquito is a more wicked fellow, but our North Michigan mosquitoes, I believe, are engaged in better work than creating malaria. In fact, I am not sure but that the "bites" of mosquitoes, in the cases of our northern cedar-cutters, and their freedom from disease in great exposure furnish the "antidote" for the malarial tendency of the