98 DIRECT INJURIES CAUSED BY INSECTS. 



in the sand three or four inches deep, leaving out the head only which 

 they cover with a handkerchief." This illustrious traveler has given an 

 account in detail of these insect plagues, by which it appears that amongst 

 them there are diurnal, crepuscular, and nocturnal species, or genera: the 

 Mosquitos or Sitnulia flying in the day ; the Temporaneros, probably a 

 kind of Culex flying during twilight ; and the Zancudos or Culiccs in the 

 night. So that there is no rest for the inhabitants from their torment day 

 or night, except for a short interval between the retreat of one species 

 and the attack of another. We learn from this author that the sting or 

 bite of the SimuUum is as bad as that of the Stomoxys before noticed.* 



The Rhagio Columbaschenis of Fabricius, a native of Banat and the 

 adjacent parts of the banks of the Danube, is a species of Simulium, and 

 one of the most obnoxious of all the insects which attack man and domes- 

 tic animals. (See Kollar's work on Obnoxious Insects ; a translation of 

 part of which, by the Misses Loudon, has recently been published. The 

 work of Pohl and KoUar on the obnoxious insects of Brazil also contains 

 many notices of their attacks upon man.) 



It is not therefore incredible that Sapor, king of Persia, as is related, 

 should have been compelled to raise the siege of INisibis by a plague of 

 gnats, which attacking his elephants and beasts of burthen, so caused the 

 rout of his army, whatever we may think of the miracle to which it was 

 attributed-; nor that the inhabitants of various cities, as Mouffet has col- 

 lected from different authors^, should, by an extraordinary multiplication 

 of this plague, have been compelled to desert them ; or that by their 

 power to do mischief, like other conquerors who have been the torment of 

 the human race, they should have attained to fame, and have given their 

 name to bays, towns, and even to considerable territories."* 



And now, which seems to you the greatest terror, that the forest should 

 resound with the roar of the lion or the tiger, or with the hum of the 

 gnat? Which evil is most to be deprecated, the neighborhood of these 

 ferocious animals, terrible as they are for their cruelty and strength, or to 



* HumboUll's Personal Narrative, E. T. v. 87. Most writers by the term mosquitos mean 

 :jnats; and for them it is here chiefly employed, but may be regarded as including both 

 plagues. 



* Theodorit. Hist. Ecd. 1. ii. c. 30. 3 Moufl'et, 85. Amoreux, 119. 



* Viz. Mos'juito Bay in St. Christopher's ; Mosquitos, a town in the Island of Cuba ; and 

 the Mosquito country in North America. Though in many cases it may be impossible to 

 prevent the attacks of gnats, it is certain that aluilecare would often secure the inmates of 

 houses, distant from stagnant waters, from these pests, for which they have solely to thank 

 their open water-tubs or cisterns in their gardens, in which they are constantly breeding. 

 Dr. Franklin, whose admirable habit of minute observation embraced all subjects, long since 

 pointed this out, and I myself found that the gnats which so annoyed us in the house we 

 occupied at Pisa late in the autumn of 1S30, as to require gauze mosquito curtains to all 

 the beds, though it was far distant from the river or any pond, all proceeded from an open 

 ornamental stone cistern in the garden, constantly left half full of water; and lam per- 

 suaded that to a similar cause may be chiefly attributed the cnats so often found in conti- 

 nental towns not situated near to canals or stagnant pools. The remedy is equally obvious 

 and easy. Either open water-tubs and cisterns should be proscribed, or a few small fish 

 kept in them to destroy the larvtjc of the gnats as fast as they breed. Trees being generally 

 found to harbor gnats, are, on this account, banished from the neighborhood of dwelling 

 houses in America and other hot countries, to the great loss of the occupants in other res- 

 pects ; but I have been informed by a friend, that at Trieste it has been observed that 

 horse-chestnut trees planted near a house, so far from encouraging gnats, drive them away, 

 none ever appearing in houses surrounded with ihe.se trees, though abundant where other 

 kinds prevail, a fact, which if confirmed in other countries, would be well worth acting 

 upon. 



