DIKECT INJURIES CAUSED BY INSECTS. 



71 



was next a question how he alone came to be singled out by 

 them ; and thus he accounts for it. It was his habit not to 

 drink at his meals ; but in the night, growing thirsty, he often 

 sipped some liquid out of a vessel made of juniper wood. In- 

 specting this very narrowly, he observed, in the chinks be- 

 tween the ribs, a white line, which, when viewed under a 

 lens, he found to consist of innumerable mites, precisely the 

 same with those that he had voided. Various experiments 

 were tried with them, and a preparation of rhubarb was found 

 to destroy them most effectually. He afterwards discovered 

 them in vessels containing acids, and often under the bung of 

 casks. ^ In the instance here recorded, the dysentery, or di- 

 arrhoea, was evidently produced by a species of mite, which 

 Linne hence called Acarus Dysenteria ; but it would be going 

 too far, I apprehend, to assert that they are invariably the 

 cause of that disease. 



That Scabies, or the itch, is occasioned by a mite, is not a 

 doctrine peculiar to the moderns. Mouffet mentions Abin- 

 zoar, called also Avenzoar, a celebrated Hispano- Arabian 

 physician of Seville, who flourished in the twelfth century, as 

 the most ancient author that notices it. He calls these mites 

 little lice that creep under the skin of the hands, legs, and 

 feet, exciting pustules full of fluid. ^ Joubert, quoted by the 

 same author, describes them under the name of Sirones, as 

 always being concealed beneath the epidermis, under which 

 they creep like moles, gnawing it, and causing a most trouble- 

 some itching. It appears that Mouflet, or whoever was the 

 author of that part of the Theatrum. Insectorum, was himself 

 also well acquainted with these animals, since he remarks 

 that their habitation is not in the pustule but near it ; a re- 

 mark afterwards confirmed by Linne ^, and more recently by 

 Dr. Adams.^ In common with the former of these authors, 

 Mouffet further notices the effect of warmth upon them in 

 exciting motion.^ Our intelligent countryman also observes 



1 Amoan. Ac. v. 94—98. 2 Mouffet, 266. 



3 Acarus sub ipsa pustula minime quaarendiis est, sed longius recessit, se- 

 quendo rugain cuticulae observatur. Amcen. Ac. v. 95. not. **. 



4 Observations, &c. 296. 



s Extractus acu et super ungue positus, movet se si soils etiam calore adju- 

 vetur. uhi supr. Ungui impositus vix movetur : si vero oris calido halitu affletur, 

 agilis in ungue cursitat. Fn. Suec. 1975. 



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