Mr. Clark'* Obfervations en the Genus Oejlrus. 310/ 



prefent very limited knowledge of them we arc able to difcover; 

 but we may venture to remark, that their effect in keeping up a 

 confiderabie degree of irritation in the membranes on which they 

 are fituated, may, perhaps not inaptly, be compared to that of a per- 

 petual iiTue or blifter. Nor is there wanting abundant proof of 

 the utility of local irritations in preventing the accefs, as well as in 

 curing disorders. We often fee a formidable difeafe quickly re- 

 moved by bliftering the Ikin, or by irritating the mucous membrane 

 of the ftomach or inteftines by a vomit or purge. The appearance 

 of exanthematous eruptions on the ikin, and the formation of local 

 abfcefTes, from the fame caufe of partial irritation, often relieve a 

 general diforder of the fyftem. The mucous membranes and the 

 ikin pofTefs this power when irritated in the moil eminent degree, 

 and to thefe the larva of the Qejirl are applied. Irritating the 

 membranes of the ftomach. in other animals would excite naufea 

 and vomiting;. but the horfe not poffemng this power, his ftomach 

 is peculiarly fitted for the ftimulus of fuch inhabitants. 



It has alfo been remarked in hofpitals, that a patient afflicted 

 with a wound,- ulcer, or other fevere local complaint, is not To fuf- 

 ceptible of the contagion of a fever or other general diforder. 



How far the accefs of thofe dreadful diforders which fometimes 

 arife of themfelves in cattle and horfes, and afterwards become conta- 

 gious, as the murrain, glanders, farcy, &c. may be prevented by 

 thefe peculiar irritations, it will not be eafy to difcover; nor whe- 

 ther that lingular tendency or difpofition in the horfe to inflam- 

 matory complaints, as the callgo of the eyes, termed moon-blindnefs, 

 inflammations of the lungs and of the bones, as fpavins-, fplints, &c. 

 may be in any degree checked or fubdued by the application of 

 thefe localjtimuli. 



In confirmation of this fuggeftion I may remark (although I am* 



aware. 



