The Evolution of Medical Science. 143 



pathy, and a host of other pathies, each contains partial 

 views of truth, and all are taught to-day at our leading 

 medical colleges. 



At last we begin to see the great general principles gov- 

 erning the actions of drugs. Foster, in his Physiology, 

 points out four : 



" 1st. By dilating the blood-vessels and increasing the 



blood supply. 

 " 2nd. By acting as a direct chemical stimulus on the 



protoplasm. 

 "3rd. By exciting secretion in the cell through reflex 



action of the nervous mechanism belonging to the 



cell. 

 "4th. By acting directly on the nervous centers of 



that mechanism."* 



To these might be added their specific effects in destroying 

 germs, their anaesthetic effects in deadening feeling, their 

 chemical effects in aiding digestive action, their osmotic 

 effects in aiding secretion and excretiouj etc. 



Only within a century has true growth gone on at any 

 decent rate. New and valuable drugs have multiplied 

 through the services of chemistry, till now we can accom- 

 plish results that the men of a generation ago would view 

 with astonishment. Within ten years some of the best 

 discoveries for easing pain, relieving fever, and curing 

 various forms of disease, have appeared, and most of them 

 are prepared synthetically, in the chemist's laboratory. 

 Had bigotry and intolerance not interfered with the prog- 

 ress in medicine during the long dark epoch lying between 

 the Empiricists of Alexandria and the Scientific Physicians 

 of the 19th Century, millions on millions of lives might 

 have been saved, and billions on billions of hours of human 

 agony quenched. Where we now are, they should have 

 been, long before the time of Avicenna.f We would then 

 have been where our children of a thousand years to come 

 will be. 



In this hasty retrospective view of the development of 

 Medical Science, you will observe that only the linear path 

 of Therapeutics has been followed. We have traced the 

 tree from its base to its apex, only incidentally referring to 



Peters' Physiology, p. 3C1. 

 t Warfare of Science, p. W. 



