DIRECT INJURIES CAUSED BY INSECTS. 83 



to the sentiments of so great a naturalist, in whom these necessary qualifi- 

 cations were united in no common degree. With respect to the dysen- 

 tery and the itch, he affirms that this had been manifested to his eyes. 

 You will wish probably to know the arguments that may be adduced in 

 confirmation of this opinion ; I will therefore endeavor to satisfy you as 

 well as I am able. The following history given by Linne seems to prove 

 the dysentery connected with these animals. 



Rolander, a student in Entomology, while he resided in the house of 

 the illustrious Swede, was attacked by the disease in question, which 

 quickly gave way to the usual remedies. Eight days after it returned 

 again, and was as before soon removed. A third time, at the end of the 

 same period, he was seized with it. All the while he had been living 

 like the rest of the family, who had nevertheless escaped. This, of course, 

 occasioned no little inquiry into the cause of what had happened. Linne, 

 aware that Bartholinus had attributed the dysentery to insects, which he 

 professed to have seen, recommended it to his pupil to examine his faeces. 

 Rolander, following this advice, discovered in them innumerable animal- 

 cules, which upon a close examination proved to be mites. It was next a 

 question how he alone came to be singled out by them ; and thus he ac- 

 counts 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 juni- 

 per wood. Inspecting this very narrowly, he observed, in the chinks 

 between 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 dis- 

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

 casks. ^ In the instance here recorded, the dysentery, or diarrhoea, was 

 evidently produced by a species of mite, which Linne hence called Aca- 

 rus 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 Abinzoar, called also Aven- 

 zoar, 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 con- 

 cealed beneath the epidermis, under which they creep like moles, gnawing 

 it, and causing a most troublesome itching. It appears that Mouffet, 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 remark afterwards 

 confirmed by Linne^, and more recently by Dr. Adams.'* In common 

 with the former of these authors, Mouffet further notices the effect of 



• Amcen. Ac. v. 94—98. 2 Mouflet, 266. 



3 Acarus sub ipsa pustula minime quaerendus est, sed longius recessit, sequendo rugam. 

 cuticulae observatur. Aman. Ac. v. 95. not. * *. 



* Observations, &c. 296. 



