Pharmacology 51 



most of the effects. Even then, for instance, cocaine 

 can be injected, with marked anesthesia about the 

 site of injection and but little remote influence. 

 Strychnine may be injected into the temporal 

 region, and its eye effects are noted only on that 

 one side. Ergot amines, when injected, raise blood 

 pressure higher when the clavicular region is en- 

 tered by the needle than when the forearm is selected. 



Ammonium salts in the blood cause medullary 

 convulsions; potassium in excess is markedly toxic 

 to all living tissues. Yet ammonium and potassium 

 salts, when injected, are excreted as rapidly as they 

 are absorbed, and are not immediately toxic. 



It takes about three days of digitalis adminis- 

 tration before sufficient quantities reach the heart 

 muscles to markedly influence that organ. Hence, 

 when we give digitalis in pneumonia to influence a 

 failing heart, we begin before the cardiac symptoms 

 arise. 



Pharmacology develops many practical points. 

 For instance, alcohol is rapidly absorbed and car- 

 ries with it substances in solution. Therefore the 

 tinctures are advantageous when prompt absorption 

 of a drug is desired. 



And yet, despite the advances of pharmacology 

 and pathology, much of treatment is empiric. We 

 know little about gout and epilepsy, but we do 

 know the value of colchicum and bromides as 

 remedies. We don't know why the salicylates have 

 so potent an influence upon acute rheumatic fever. 

 So, then, let the pharmacologist be modest in his 

 claims and in his criticism, for empiricism still has 

 a place and much remains to be explained. 



Pharmacology has yet many problems to solve. 



