DIRECT INJURIES CAUSED BY INSECTS. 47 



by men acquainted with Entomology as well as the science of diseases. 

 Considerable deference and attention, however, are certainly due to the 

 sentiments of so great a naturalist, in whom these necessary qualifications 

 were united in no common degree. With respect to the dysentery 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 confirma- 

 tion of this opinion ; I will therefore endeavour to satisfy you as well as I 

 am able. The following history given by Linne seems to prove the dysen- 

 tery 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 faces. Rolander, 

 following this advice, discovered in them innumerable animalcules, 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 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 between the ribs, a 

 white line, which, when viewed under a lens, he found to consist of innu- 

 merable 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 bungs of casks. 1 In the in- 

 stance here recorded, the dysentery, or diarrhoea, was evidently produced 

 by a species of mite, which Linne hence called Acarus Dysenteries ; 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. 2 Joubert, quoted by the same author, de- 

 scribes 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 troublesome itching. It appears that Mouffet, or whoever was the 

 author of that part of the Theatrum Insectorum, was himself also well ac- 

 quainted with these animals, since he remarks that their habitation is not in 

 the pustule but near it ; a remark afterwards confirmed by Linne 3 , and more 

 recently by Dr. Adams. 4 In common with the former of these authors, 



* Amcen. Ac. v. 9498. 3 MoufFet, 266. 



8 Acarus sub ipsa pustula minimi quserendus est, sed longius recessit, sequeiido 

 rugam cuticulae observatur. Amcen. Ac. v. 95. not. **. 

 4 Observations, &c. 296. 



