THE STUDY OF PHYSIOLOGY. 45 



occupied at the end of the seventeenth century. The progress of 

 therapeutics is to be marked, not by the labors of " practical raen " 

 (who, by the way, are of all the most theoretical, only that their theo- 

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

 cartes and Newton, of Hooke and Grew, of Lavoisier and Davy and 

 Volta, of Marshall Hall and Johannes Miiller. 



The history of science proves that unconnected, unsystematic, in- 

 accurate observations 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 excep- 

 tion, upon metaphysical theories. In dealing with uneducated per- 

 sons, both of the lower and higher ranks, physicians find abundance 

 of theories as to the nature and the origin of disease, and of sugges- 

 tions as to its cure. The only thing which would be of value is what 

 we can scarcely ever get — an accurate observation of what they see 

 and feel. Every fallacy of popular medicine, every solemn medical 

 imposture, is the ghost of some long defunct doctrine of the schools. 

 Therefore it is that common experience is almost absolutely useless in 

 practical arts. They, without exception, depend for their progress 

 upon the advance of science— that is, upon methodical, continuous, 

 and scrupulously accurate observations and experiments. 



Many important advances in the practice of medicine have been 

 gained by direct and intentional experiments instituted with a thera- 

 peutical object. Such was the Hunterian operation for aneurism, the 

 process of skin-grafting, and subperiosteal operations ; such was the 

 administration of chloroform and the introduction of nitrite of amyl, 

 chloral hydrate, and carbolic acid. Such direct experiments still go 

 on, and among them deserve mention, for the skill and the untiring 

 patience with which they were carried out, those investigations upon 

 the action of various drugs on the secretion of bile for which we are 

 indebted to Professor Rutherford and his coadjutors. Even appar- 

 ently accidental discovei'ies were not made accidentally. Hundreds of 

 country surgeons must have been familiar with the cow-pox, and have 

 seen examples of the immunity it conferred from the more tcn'ible 

 variola, but he who discovered vaccination was no falsely-called prac- 

 tical man. He was a man of science, the friend of Hunter and of 

 Cavendish, an anatomist and natural philosopher. The fruits of Jen- 

 ner's discovery are spread over the whole earth. This humble village 

 doctor has saved more lives than the most glorious conqueror de- 

 stroyed, but his name is little honored, and the only monument to his 

 memory has been banished from association with vulgar kings and 

 skillful homicides to an obscure corner of the great city where his 



