TRANSACTIONS OF SECTION D. — DEPT. ANATOMY AND PHYSIOLOGY. 407 



Lave been first worked out in the laboratory the more safe and the more lucrative 

 will be their application in the field. 1 



Still more important is the relation of Physiology to the national Health. The 

 commonplaces of hj'giene which are now, one may be thankful to say, taught, if 

 not practised, in almost every schoolroom and factory in England, are the direct 

 results of the abstruse researches of Boyle and Priestley, of Lavoisier and Pasteur 

 Ages of experience did not teach mankind the value of fresh air or the innocence 

 of clean water. Indeed, I have myself heard astonishment expressed by a German 

 professor at the peculiar immunity with which English skins will bear the daily 

 and unstinted application of soap and water. 



If the art of keeping a community in health is but the application of plain physio- 

 logical laws, it is no less true that the art of restoring the health, curative, as 

 distinct from preventive Medicine, rests upon the same basis. In former days the 

 physician was one who recognised what he called the disease of his patient, who 

 referred to his books of precedents as a lawyer to his statutes, and who prescribed 

 a proper remedy to cast out the disease. We now know that dis-ease is, as the 

 name implies, a purely subjective conception. The disease of a host is the health 

 of the parasite, and we cure a human sufferer by poisoning the animals or plants 

 which interfere with his comfort. The same changes which in the old man are 

 the natural steps of decay, the absence of which after a certain age would be truly 

 pathological, are the cause of acute disease in the young. Pathology has no laws 

 distinct from those of Physiology. 



When these now obvious considerations are thoroughly understood, it clearly 

 follows that all ' systems of medicine ' are in their very nature condemned. All 

 that the art of Medicine can do is to apply a knowledge of natural laws, of me- 

 chanics and of hydrostatics, of botany and zoology, of chemistry and electricity, of 

 the behaviour of living cells and organs when subjected to the influence of heat and 

 of cold, of acids and alkalis, of alcohols and ethers, of narcotics and stimulants, so as to 

 modify certain deviations from ordinary structure and function which are productive 

 of pain, or discomfort, or death. It is, therefore, plain that rational medicine, or 

 keeping right and setting right the human body must rest upon a knowledge of its 

 structure and its actions, just as a steam-engine or a watch cannot be mended upon 

 general principles, but only by one who is familiar with their construction and 

 working, and who can detect the source of their irregularity. 



An objector may say : — ' Admitting that medicine is an art, it is a purely em- 

 pirical art. You cannot detect the origin of many of the maladies which you are 

 yet able to cure ; your best remedies have not been obtained by scientific experi- 

 ment, but by chance observation and accumulated experience ; and if you doctors 

 would give more time to practical therapeutics, that is, to finding out what is good 

 for the several aches and pains we complain of, you would spend your time better 

 than in abstruse researches into microscopic anatomy or the properties of a dead 

 frog's muscle.' 



The answer to the objection is an appeal to fact. For centuries, so called 

 observation and experience left medicine in the condition it occupied at the end of 

 the 17th century. The progress of therapeutics is to be marked, not by the labours 

 of 'practical men,' (who, by the way, are of all the most theoretical, only that 

 their theories are wrong), but by the, at first sight, unconnected studies of Des- 

 cartes and Newton, of Ilooke and Grew, of Lavoisier and Davy and Volta, of 

 Marshall Hall and Johannes Midler. 



The history of science proves that unconnected, unsystematic, inaccurate obser- 

 vations are worth nothing. For untold ages men have had ample opportunities of 

 studying the indications of the weather, and have felt the utmost desire to obtain 

 a knowledge of what they portend. Yet it may fairly be said that nothing had 

 been done to the purpose, until combined and systematic observations were made 

 in this country and America. The fact is, that popular notions do not rest upon 

 experience or observation. They rest, with scarcely an exception, upon metaphysical 

 theories. In dealing with uneducated persons, both of the lower and higher ranks, 



1 I need only refer to the fruitful labours of Mr. Lawes and Dr. Gilbert in this 

 direction. 



