Botanic Remedies 151 



auricular contraction. Ultimately, the ventricle is 

 arrested in systole, while the auricles continue to 

 beat for some time. This order of phenomena may 

 vary somewhat under different dosage. 



The first or therapeutic stage of digitalis action 

 requires some further comment. There is an in- 

 crease in amplitude of the beat and volume output, 

 especially in the exhausted heart. The auricular 

 contraction is strengthened, with a slight decrease 

 in diastolic relaxation (Straub). There are other 

 minor influences; but the output per beat and per 

 minute is increased; and, more particularly in the 

 mammalian heart, the heart is slowed, owing to a 

 central stimulation of the vagus, the ventricles 

 empty themselves more completely than formerly, 

 and diastole may be either diminished or increased; 

 the beat becomes more regular (Clark). 



The digitalis group of drugs, in sufficient dosage, 

 produce vaso-constriction (more with digitoxin than 

 with strophanthin) and raise blood-pressure. It is 

 to be remarked here that in man the ordinary 

 therapeutic doses do not raise blood-pressure. This 

 is well proven by several recent investigators. 



There is little action on renal secretion in the 

 normal animal; but the increase in the cardiac out- 

 put induces marked diuresis in certain diseases. 



All of the digitalis group of drugs are more or 

 less of gastro-intestinal irritants, squill being an 

 emetic, and euonymus a purgative. 



The action on the heart muscle is purely selective, 

 other muscular tissue not being influenced. 



No active preparation of digitalis is yet known 

 which can be injected under the skin without 

 causing more or less pain and inflammation (Dixon). 



