INTRODUCTION. 473 



last effect, which we consider ; and in so far every part of the 

 chain may be considered as a cause of the last effect. Thus, a 

 man on board a ship takes up a lighted match, and applies it 

 to the touch-hole of a loaded cannon ; this kindles the gun- 

 powder ; this produces an explosion, which pushes on with 

 great rapidity the bullet ; this bullet strikes on a piece of tim- 

 ber, divides it into splinters, and these splinters happen to hit 

 with great force the head of a man standing by, so that he is 

 instantly killed. Now this death may be traced through this 

 whole series of causes. The same applies to most other events 

 in nature ; and hence it is common to apply the term cause to 

 each of these actions or motions. There is often, however, a 

 necessity for distinguishing them into the more immediate and 

 the more remote causes : in the above case, the stroke of the 

 splinter was the immediate cause of the man's death ; the 

 whole series besides this were the remote causes. This very 

 necessary distinction has been much employed in physic, and 

 has given rise to the terms proximate and remote causes. 



" Disease, considered as the effect of a particular state of the 

 body, may be traced backwards in a series of causes, all of 

 which may be called remote; but physicians have not been 

 thus limited in taking the very immediate as the proximate 

 cause. This will be best understood by an example. Pain in 

 a joint constitutes the disease we call Rheumatism ; in tracing 

 the causes, we find that the pain is owing to an overdistention 

 of the sensible fibres, in consequence of an overstretching of the 

 blood-vessels. We further find, that this overstretching is 

 caused by the increased impetus of the blood from a stimulus 

 applied to those vessels, often to the whole system, but often to 

 particular vessels ; and that this has for its cause the application 

 of cold. Now the application of cold may be said to be the only 

 proper remote cause ; but the stimulus, the increased impetus, 

 the overdistention, may all be considered as proximate causes. 



" That the meaning of this may be better understood, we take 

 another example. A fluctuating swelling of the abdomen forms 

 the disease which we call Ascites. We find that it has for its 

 cause a quantity of water collected in the cavity of the abdo- 

 men, which may be further traced to an increased exhalation 



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