398 THE CANADIAN ENTOMOLOGIST 



they say causeth the Murrain, which is the Plague in Cattle, 

 and it is very infectious. 



It has been observ'd that Plagues, and the most contagious 

 Distempers, have commonly happen'd in those Years when 

 the Easterly Winds have more than ordinary prevail'd in the 

 Spring and Summer Seasons; then the Air comes to be infected, 

 and rarely or ever at other times. These Winds we see bring 

 Caterpillars, and many differing Insects and Flies, which 

 meeting with places fitly adapted to nourish them they are 

 there brought to their winged state, which I conceive is the 

 same in the invisible Animals as in the visible; nor indeed in 

 any part of the Earth, or Waters. 



The west winds he considered, carried back "the remainder 

 of these Pestiferous Insects which yet survdve, to the Country 

 from whence they came." He continues: 



I have not yet found that any Winds, except the 

 East Winds, such as pass over Tartary, bring any Infection 

 with them, nor have I ever heard of Pestilential Distempers 

 in any part of the World, unless in such places only where 

 the Tartarian Winds reach; Tartary being a country full of 

 Woods, Boggs, and Fens it ssems the most capable of pro- 

 ducing these Creatures in abundance, which may be carry'd 

 by the Wind to certain places in search after their Food, as 

 are Locusts and some certain Birds, which are know to pass 

 from one Country to another. 



Experience shews us how much Insects delight in stinking 

 Places, and that they increase much faster in uncleanly Cities, 

 such as London was formerly, than in cleaner Places; but the 

 city of London having been for the most Part burnt the year 

 after the Pestilence, its streets were enlarg'd, many drains 

 were made and good Laws were put in execution for keeping 

 the City clean, and it has not had any Plague ever since. 



His reference to the occurrence of "Epidemical Distemper" 

 in Leghorn contains the following: 



