LECTURE I. 



Delivered on June zoth. 

 THE CHEMICAL CONTROL OF THE FUNCTIONS OF THE BODY. 



MR. PRESIDENT AND GENTLEMEN, From the remotest ages the 

 existence of a profession of medicine, the practice of its art, and its 

 acceptance as a necessary part of every community, have been founded 

 on a tacit assumption that the functions of the body, whether of growth 

 or activity of organs, can be controlled by chemical means ; and research 

 by observation of accident or by experiment for such means has resulted 

 in the huge array of drugs, which form the pharmacopoeias of various 

 civilised countries and the common armamentarium of the medical 

 profession throughout the world. The practice of drugging rests on the 

 supposition that the functions of the body can be influenced in a normal 

 direction by such means. I propose in these lectures to inquire how far 

 such a belief is consonant with our own knowledge of the physiological 

 workings of the body ; how far, that is to say, the activities and growth of 

 the different organs of the body are determined and coordinated among 

 themselves by chemical substances produced in the body but capable ot 

 classification with the drugs of the physician. If a mutual control, and 

 therefore coordination, of the different functions of the body be largely 

 determined by the production of definite chemical substances in the body, 

 the discovery of the nature of these substances will enable us to interpose 

 at any desired phase in these functions, and so to acquire an absolute 

 control over the workings of the human body. Such a control is the goal 

 of medical science. How far have we progressed towards it ? How far 

 are we justified in regarding its attainment as possible ? 



I hope to be able to vindicate to you the assumption which is at the 

 basis of medical practice, and to show that the activities of, at any rate, the 

 large majority of the organs of the body are coordinated among themselves 

 by the production and circulation of chemical substances. The results 

 of physiological researches up to the present justify us in the faith that, 

 within a reasonable space of time, we shall be in the possession of chemical 

 substances which are normal physiological products, and by means ot 

 which we shall be in a position to control not only the activities but also 

 the growth of a large number of the organs of the body. 



In man and the higher animals, the marvellous adaptations effected 

 by means of the central nervous system are so much in evidence, that 

 physiologists have been tempted to ascribe every nexus between distant 

 organs to the intervention of the nervous system ; the more so because 

 by this means an adaptation to changes, internal or external, can be 



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