39 



infective dust from the coaches, especially the sniolving cars. On our rail- 

 ways today, men who are constantly suffering from the evil effects of in- 

 haling a polluted atmosphere, manifested by colds and coughs, and ca- 

 tarrhs, by weeping eyes and noses, and are inclined to be sickly and de- 

 mand frequent vacatious, such men are not long retained in these posi- 

 tions by the railway managers— -the weeding out process goes on all tlie 

 time. Similarly a canal-boat man who was readily attacked by malaria 

 and who lost much time on account of it, was not long retained in the po- 

 sition ; those who retained their positions were the more resistent ones. 



Facts are sometimes explainable by different theories. In the following 

 story, taken from Drake, the substitution of "mosquitoes" for "whisky," 

 as the apparent cause, more satisfactorily accounts for the facts or condi- 

 tions. It should be remembered that the Anopheles mosquitoes are night- 

 biters, that ordinai'ily they fly low, and do not frequent rooms or housed in 

 which tobacco is smoked. 



A few miles to the east of Fort Wayne there was a densely wooded 

 swamp, known as the Mainnee or Black Swamp, which extended oh into 

 Ohio. This swamp seems to have been salubrious ; it was free from ma- 

 laria, and families who settled in it "enjoyed uninterrupted autunmal 

 health for three or four years," until malaria was brought in by other set- 

 tlers. In 18.''kS excavations were made in the eastei'n end of this wet. section 

 for a canal. "The laborers, four or five luuidred in mnnber, were chiefly 

 Irish, who generally lodged in temporary shanties, while some occupied 

 bowers formed out of the green limbs of trees. * * * One contractor 

 kept a liquor store, and sold whisky to all whom he employed, which was 

 drank freely * * * the mortality H'rom malaria) amcmg them was 

 very great. Another lodged his operatises on straw beds, in the upper 

 room of a large frame house, made them retire early, kept them from the 

 use of whisky, and nearly all escaped the disease." 



In this connection it may be said that in the malaria prophylaxis of 

 Italy, screens on houses, and an avoidance of the mosquitoes outside of the 

 houses, are of the greatest importance. In our own coiuitry the use of 

 screens in windows and doors is a most important factor in the diminu- 

 tion of many ailments and diseases that formerly prevailed during the time 

 of mosquitoes and flies, cholera infantum not the least among them. 



The belief in the injuriousness of night air, still so prevalent among 

 us, is readily traced to the days of the night-biting Anopheles mosquitoes 

 filled with the germs of malaria. These mosquitoes do not live in cities, or 



