MEDICAMENTS AND LIFE. 221 



of one neutralize those of the other. Physicians profess- 

 ing the treatment of the eye are beginning to take advan- 

 tage of these properties. 



We find that every alkaloid, apart from a general action 

 on the system, has also a more special one upon a certain 

 part of the system, or a certain organ. Now, digitalis is 

 a poison, or a remedy in heart-disease. Since Cullen's 

 time, although he had so clearly indicated the true uses 

 of that medicine, it was but little employed, except as a 

 diuretic. Only of late years Traube, professor at Berlin, 

 and Hirtz, professor at Strasbourg, have again taken up 

 the study of this vegetable product, and again brought 

 into view, by clinical experiments and results, the impor- 

 tance of the effect it produces upon the circulation and 

 heat of the system. Thanks to the power it possesses of 

 making the heart's pulsations slower, and consequently 

 checking the movements of the blood, this agent is of ser- 

 vice in all diseases, particularly those of a febrile kind, in 

 which the activity of internal heat needs to be lessened. 

 Digitalis owes these properties to a substance which till 

 very lately there had been no means of isolating entirely. 

 We were able ^only to obtain from it a formless substance, 

 yellowish and complex, and varying in force of action. 

 Within a few months a skillful chemist, Nativelle, has 

 succeeded in extracting from it a principle quite definite 

 in composition, in fine needles of crystals, white and ex- 

 tremely bitter, and which is true digitalis. The Academy 

 of Medicine awarded an extraordinary prize to the author 

 of this discovery. Digitaline, prepared by the new method, 

 is so powerful that, in a dose of a quarter of a thousandth 

 of a gramme only, with the human subject, it affects the 

 movements of the heart, and in one of five thousandths of 

 a gramme would produce death ! On the other hand, its 

 effect is so certain and so characteristic that, when digitaline 

 exists in a mixture in quantity so minute that it can be dis- 



