48 DIRECT INJUllIES CAUSED BY INSECTS. 



MoufFet further notices the effect of warmth upon them in exciting motion.* 

 Our intelligent countryman also observes that they cannot be Pediculi, since 

 they live under the cuticle, which lice never do." In the epistle dedi- 

 catory, the editor speaks also of them as living in burrows which they have 

 excavated in the skin near a lake of water; from which, if they be ex- 

 tracted with a needle and put upon the nail, they show in the sun their 

 red head and the feet with which they walk.^ And to close my veteran 

 authorities, Junius thus explains the word Acarus, as I find him quoted in 

 Gouldman's useful dictionary, " A small worm, which eats under the skin, 

 and makes burrows in itching hands." ^ 



In more modern times, microscopical figures have been added to descrip- 

 tions of the insect. Bonomo first furnished this valuable species of eluci- 

 dation. His figures, however, which are copied by Baker in his work on 

 the microscope, are far from accurate.^ Those of De Geer and Dr. Adams 

 are much more satisfactory, and mutually confirm eacli other.** From 

 them it is evident that the same insect inhabits the scabies of Sweden and 

 Madeira. Dr. Bateman, in the letter before alluded to, informs his corre- 

 spondent, that he had seen that from Madeira, and gives it as hi? opinion, 

 that there cannot be a doubt of the existence of an Acarns Scahiei; an 

 opinion which he repeats in his late work on Cutaneous Diseases, and which, 

 according to Hermann^, has been also rendered unquestionable by Wicb- 

 mann in his Etiologie de la Gale (Hanovre, 1786), a work I have not had 

 an opportunity of consulting. From all this we may regard the point as 

 so far settled that an animal of this kind exists at least as an occasional 

 concomitant of scabies. 



This fact being ascertained, a more complex inquiry remains, which 

 branches out into two distinct questions. Is scabies always produced by 

 these insects ? Or, if this be not the case, is the animate scabies a distinct 

 disease from the inanimate ? 



It is very remarkable that Linne, a physician as well as a naturalist, 

 and De Geer, one of the most accurate observers that evei" existed, 

 should both assign the insect in question as the undoubted cause of the 

 common scabies of their country; the one applying to the disease he was 

 speaking of the epithet of comnmnissima , and observing the fact to be 

 notorious {cuique liquet), and the other designating it by its well known 

 French name. La Gale.^ And is it not equally remarkable that such 



1 Extractus acu et super ungue positus, movet se si solis etiam calore adjuvetur. 

 Ubi supr. Ungui impositiis vix movetur : si vero oris calido lialitu aiHetur, agilis in 

 ungue cursitat. Fn. Suec. 1975. 



2 Neque Syrones isti sunt de pediculorum genere, ut Johannes Langius ex Aris- 

 totele videtur asserere : nam illi extra cutem vivunt, hi vero non. Uhi sjipr. 



3 Imo ipsi Acari prae exiguitate indivisibiles, ex cuniculis prope aqu.-e lacum quos 

 foderunt in cute, acu extracti et ungue impositi, caput rubrum, et pedes quibus 

 gradiuntur ad solem produnt. p. vi. 



4 Teredo sive exiguus venniculus, qui subter cutem erodit agitque cuniculos in 

 pruriginosis manibus. Gouldman tells us these Acari were also called Hand-worms. 

 Another I>nglish name is also given in JMoufiet, viz. Wlteak-worms. 



5 Osservazioni intorno a pellicelli del corpo umano Jatte dal Uottor Gio. Cosimo 

 Bonomo, &c. f. 1 — 3. Baker, On Microsc. i. 1. 13./. 2. 



6 DeGeer,'vii. <. 5./. 12. 14. 

 1 M6m. Apterohgique, 79. 



* 1 am informed by my learned friend Alexander BlacLeay, Esq., late secretary 



