Memoirs of Erasmus Darwin, M. D. 137 



*' The common names of diseases are not well adapted to 

 any kind of classification, and least of all to this from their 

 proximate causes. Some of their names in common lan- 

 guage are taken from the remote cause, as worms, stone of 

 the bladder; others from the remote effect, as diarrhoea, 

 salivation, hydrocephalus ; others from" some accidental 

 symptom of the disease, as tooth-ache, head- ache, heart- 

 burn ; in which the pain is only a concomitant circum- 

 stance of the excess or deficiency of fibrous actions, and 

 not the cause of them. Others again are taken from the 

 deformity occasioned in consequence of the unnatural 

 fibrous motions, which constitute diseases, as tumours, 

 eruptions, extenuations : all these therefore improperly 

 give names to diseases ; and some difficulty is thus occa- 

 sioned to the reader in endeavouring to discover to what 

 class such disorders belong. 



*' Another difficulty attending the names of diseases is, 

 that one name frequently includes more than one disease, 

 either existing at the same time or in succession. 

 Thus the pain of the bowels from worms is caused by the 

 increased action of the membrane from the stimulus of 

 those animals : but the convulsions which sometimes suc- 

 ceed these pains in children, are caused by the consequent 

 volition, and belong to another class. 



*' To discover under what class any disease should be ar- 

 ranged, we must first investigate the proximate cause : thus 

 the pain of the tooth-ache is not the cause of any diseased 

 motions, but the effect ; the tooth-ache therefore does not 

 belong to the class of Sensation. As the pain is caused by 

 increased or decreased action of the membranes of the tooth, 

 and these actions are owing to the increase or decrease of 

 irritation, the disease is to be placed in the class of Irrita- 

 tion. 



" To discover the order, it must be inquired, whether the 

 pain be owing to increased or defective motion of tha 

 pained membrane; which is known by the concomitant 

 lieat or coldness of the part. In tooth-ache without inflam- 

 mation there is generally a coldness attends the check in its 

 vicinity ; as may be perceived by the hand of the patient 



himself, 



