viii PREFACE. 



The common names of difeafes are not well adapted 

 to any kind of clarification, and lead of all to this, from 

 their proximate caufes. Some of their names in com- 

 mon language are taken from the remote caufe, as 

 worms, (lone of the bladder ; others from the remote 

 effect, as diarrhoea, falivation, hydrocephalus ; others 

 from fome accidental fymptom of the difeafe, as tooth- 

 ach, head-ach, heart-burn ; in which the pain is only a 

 concomitant circumftance of the excefs or deficiency of 

 fibrous actions, and not the caufe of them. Others 

 again are taken from the deformity occafioned in confe- 

 quence of the unnatural fibrous motions, which confti- 

 tute difeafes, as tumours, eruptions, extenuations ; all 

 thefe therefore improperly give names to difeafes ; and 

 fome difficulty is thus occafioned to the reader in en- 

 deavouring to difcover to what clafs fuch diforders 

 belong. 



Another difficulty attending the names of difeafes is. 

 that one name frequently includes more than one difeafe* 

 either exifting at the fame time or in fucceffion. Thus 

 the pain of the bowels from worms is caufed by the in- 

 creafed action of the membrane from the ftimulus of 

 thofe animals ; but the convulfions, which fometimes fuc- 

 ceed thefe pains in children, are caufed by the confequent 

 volition, and belong to another clafs. 



To difcover under what clafs any difeafe mould be ar- 

 ranged, we mud firft inveftigate the proximate caufe ; 

 thus the pain of the tooth-ach is not the caufe of any 

 difeafed motions, but the efTecl; ; the tooth-ach there- 

 fore 



