530 On Medical Entomology. 



I^rst volume of the Manchester Memoirs, by Mr. Henry, 

 in the second volume of the same work by Dr. Barnes, and 

 in the hundredth number of the Lounger, that the above 

 paper assumes the principle as being fully established. 



XL. An Essay on Medical Entomology. By F. Chau- 

 METON, Physician to the Anvy^. 



In his tarn parvis tamque nullis quae ratio ? quanta vis ? Plin'. 



W HEN we cast our eyes on the immense quantity of vo- 

 lumes which have entomology for their object, one is in- 

 clined to believe that insects have been sufficiently consi- 

 dered under every point of view. Naturalists, philosophers, 

 and physicians, seem to have united their efforts to give a 

 most complete history of them. Some have endeavoured 

 to trace out their elegant forms and varied shades, and 

 others have carefully studied and described their wonderi'ul 

 metamorphoses. The latter have exhibited the interesting 

 view of their habits and manners, and have presented us 

 with some of them as moclds ; the former have acquired 

 more right to the public gratitude, by pointing out those 

 insects which it is necessary to destroy, either because they 

 contain a poisonous liquor, or on account of the destruction 

 which they occasion. It must indeed be confessed, that 

 useless and hurtful insects are far more numerous than those 

 from which society derives real advantages. We must not, 

 however, forget, that the class of insects furnislios us with 

 honev, silk, cochineal, &c., and that medicine obtains 

 from it efficacious aid against human infirmities. It is 

 under the latter point of view that I propose, in this cssav, 

 lo examine entomology. 



The antients were satisfied with distributing insects into 

 different groupes, according to the diversity of their resi- 

 dence ; and as they did not assign precise characters to the 

 species they described, it is very difficult, and often impos- 

 sible, to form oxact ideas of them. 



It was not till towards the middle of the sixteenth cen- 

 tury that the learned Conrad Gesner endeavoured to cltar 

 up tl)c confusion which prevailed in zoology ; and his la- 

 bours have been a fruitful mine to his successors. Aldro- 

 vandus, Swanunerdam, Ray, and Lister, followed worthily 

 in his steps; but it was reserved to the immortal Linnaeus 



* TsQ'^wh'i J'MULii lie P'-jsique, Fructidor, an iz, 



to 



