20 METHODOLOGICAL INTRODUCTION. 



such a separation, for how much mental energy has been wasted, 

 as it were, in the investigation of unattainable things ; and among 

 these we may class pathological chemistry, when not based on 

 physiological principles. It would assuredly be going too far, to 

 assert that the natural enquirer should undertake no experiment that 

 could not afford a definite solution to a well-grounded question ; 

 but it must be admitted that there is an almost countless number of 

 pathologico-chemical experiments which have yielded no result, and 

 which obviously could yield none ; and indeed it seems scarcely 

 comprehensible that we should attempt to understand that 

 which is abnormal, while we continue ignorant of that which is 

 normal. Before we can institute a comparison between two things, 

 we must be familiarly acquainted with at least one. Here we do 

 not by any means wish to maintain that no pathologico-chemical 

 enquiries should be prosecuted, for this would be as absurd as to 

 withhold our attention from pathology until we supposed ourselves 

 fully enlightened on the subject of physiology. We would, on 

 the contrary, limit our objections to those analyses of pathological 

 products which have no relation to any one leading idea, are devoid 

 of connexion with any scientifically established fact, and do not bear 

 upon general chemical or physiological propositions. Such inves- 

 tigations are so numerous, that our weekly periodicals are seldom 

 without one or more analyses of diabetic urine. These results 

 would, doubtless afford additional proof of the well-established 

 fact that sugar is present in diabetic urine, if we did not feel 

 assured that the diabetes was not diagnosed until the existence of 

 sugar had been demonstrated in the urine. We seldom meet with 

 any observation on the relation existing between the quantity of 

 sugar excreted in a given time, and the quantity of food taken 

 during the same period ; while other and similar considerations of 

 equal importance are also usually disregarded. 



The severance of pathological from physiological chemistry is 

 even less admissible in a scientific than in a practical point of 

 view. We will not here pass judgment on the obscure abstract 

 idea of disease, but whatever value such a view may have in 

 reference to life and medical practice, and however pathologists 

 may strive artistically to define it, it must continue illogical in 

 reference to theory and science. But whatever view we may 

 here adopt, it must be admitted that pathological and physio- 

 logical chemistry cannot exist independently, a view requiring no 

 circumstantial proof. The power and the law remain the same, 

 whether the points of application be more or less remote from the 



