XS3 Memoirs of Erasmus Danvin, M. D. 



himself, compared with the opposite cheek. Hence odon- 

 talgia is found to belong to the order of Decreased Irritation. 

 The genus and species imi-t be found by inspecting the 

 synopsis of the second order of the class of Irritation. See 

 Class I. 9. 4. 13. 



" This may be further elucidated by considering the na- 

 tural operation of parturition ; the pain is occnsioned by the 

 increased action or distention of the vessels of the uterus, 

 in consequence of the stimulus of the foetus ; and is there- 

 fore caused by increased irritation ; but the actions of the 

 abdominal muscles in its exclusion are caused by the pain, 

 aAd belong to the class of Increased Sensation. See Class 

 If. I. I. 12. Hence the difficulty of determining, under 

 what class of diseases parturition should be arranged, con- 

 sists in there being two kinds of diseased actions compre- 

 hended under one word ; which have each their ditferent 

 proximate cause. 



"In Sect. XXXIX. 8. 4., and in Class II. 1. 1. 1., \vc 

 have endeavoured to give names to four links of animal 

 causation, which conveniently apply to the classification of 

 diseases : thus in common nictitation, or winking with the 

 eyes without our attention to it, the increased irritation is 

 she proximate cause -j the stimulus of the air on the dry 

 comea is the remote cause ; the closing of the eyelid is the 

 proximate effect ; and the diflusion of tears over the eye- 

 ball is the remote effect. In some cases two more links of 

 causation may be introduced ; one of them may be termed 

 the pre-remote cause ; as the warmth or motion of the at- 

 B)ospbere, -vhich causes greater exhalation from the cornea. 

 And the other the post-remote effect ; as the renewed 

 pellucidity of the cornea; and thus six links of causatior^ 

 may be expressed in words. 



"But if amid these rennote links of animal causation any of 

 the four powers or faculties of the sensorium be introduced, 

 the reasoning is not just according to the method here pro-r 

 posed ; for these powers of the sensorium are always the 

 proximate causes of the contractions of animal fibres ; and 

 therefore in true language cannot be termed their remote 

 causes. From this crilc/iop it may always be determined, 



wheth?!;' 



