I70 THE CAUSATION OF DISEASE. 



Sj -f E 10 = 1 1 ; and when the fit is excited by the barest peri- 

 pheral irritation, we may symbolically express the fact thus : 

 S 9 + E 2 = ii. 



And it is worthy of note that in such cases as the above we 

 may cure the disease by reducing the number of units whether 

 of S or of E. An individual is suffering, let us say, from 

 neuralgia of the fifth nerve. He is anasmic and haggard-looking, 

 and on inquiry we find that he has been over- worked and worried. 

 Examination of the teeth discloses on the side of the pain a de- 

 cayed molar, which is tender to the touch. Now, it may happen 

 that the neuralgia disappears after withdrawal of the offending 

 tooth, in which case the causation may have been somewhat as 

 follows : S 6 + E 5 = 1 1 . By removing the five units of causation, 

 we cure the disease. On the other hand, the neuralgia may 

 continue unabated after the tooth has been drawn, when the 

 causation would be thus represented: S n -fE = II. Such a 

 case, however, may not infrequently be cured by diminishing the 

 pathogenic value of S. Supposing, for instance, the causation 

 to be more or less accurately represented by the formula 

 S 6 + E., it will follow that, if by tonics and rest we can reduce 

 the S 6 to S„ the patient will be cured. 



We are, indeed, often called upon to fix the pathogenic value 

 of E and S respectively in cases like the above, for our treatment 

 may depend upon the conclusion we arrive at. Some physicians, 

 for instance, value E (note, that I am not now talking of the 

 external E) at a very low figure in such disorders as epilepsy and 

 neuralgia — practically ignoring it, in fact ; while others assume 

 the chief or a large share of causation to reside within it.* 



I have given these few instances, and might add many more, 

 with a view to show how much the numerical expression of 

 our thoughts would tend to give them a precision which they 

 otherwise lack. 



A structural deficiency, or disease proclivity, may be tem- 



* It is evident, from a perusal of Dr. Gowers' work upon Epilepsy, that he 

 does not attach much importance to the part played by "peripheral irritation" 

 in the causation of this disorder ; and it may be said that the great purpose of 

 Dr. Anstie's treatise on Neuralgia was to show that the essential cause of this 

 complaint lay in the sensory centres. 



