EXPERIMENTAL INVESTIGATION OF THE 

 ACTION OF MEDICINES. 



(Reprinted from The British Medical Journal, 1871, 1872, and ]S75.) 



I. — The Standahd of Health. 



Britixh Medical Journal, 1871, April 22nd, p. 413, and April 29tli, p. 439. 



Modes of rnvastigation.— Pathology. — Pharmacology. — Life. — Conditions of 

 Health and Disease. — EHectof Drugs. — Direct and Indirect Action. — Local 

 and Remote Action. — Dose. — Modification of Dose. — Cumulative Action. — 

 Efl'ect of Habit, Climate, Fasting. — Form of Administration. — Effect of 

 large and fmall Doses. — flomoeopathy. — iJ'onstitution and Idiosyncrasy. — 

 Explanation of these from Experiments on Animals. — Connection of 

 Chemical Constitution and Physiological Action. 



The usual mode of investigating the action of a remedy is to 

 give it to a patient during an illness and observe what changes 

 occur in the symptoms after its administration. But it not 

 unfrequently happens that medicines are given without any 

 distinct change in the symptoms ensuing. Even when one does 

 take place, we very often cannot be sure that it is due to the 

 medicine, and not to the course of the disease or some other 

 modifying cause. For, if the remedy and the disease are both 

 at work together, it is obviously impossible for us to decide 

 Avhat part of the result is due to the one and what part to the 

 other, unless we know what the course of the disease would 

 have been without the medicine, and what action tlie medicine 

 would have had if the disease had not been present. Any 

 attempt to investigate the action of a remedy by giving it under 

 such circumstances is like that of a riHeman who should 

 attempt to learn shooting by practising only at dusk, when he 

 could not see the butt, much less the bull's eye. He might go 

 on practising forever in this way without making any improve- 

 ment ; for, when he missed, he would never know whether it 

 was because he had not seen the mark properly or had not 

 aimed steadily at it. If he wish to learn, he must practise by 

 daylight, when he can clearly see the mark, and can thus be 



