HYDE: EXPERIMENTS ON THE SKATE, 



61 



Table XVI. Toxic and Antitoxic 

 Solutions. 



The following is a resume of the conclusions drawn from 

 the different experiments : 



M% NaCl increases the force of cardiac and respiratory- 

 rhythm and blood pressure, but is indifferent to the rate during 

 the first five minutes. Weaker solutions are neutral, and a 

 stronger, m 1, solution is rather depressing except to heart 

 force and blood pressure, while 2m is generally depressing, 

 prolonging systolic and inspiratory phases. 



The different strengths of KCl solutions proved depressing 

 to the activities under consideration. Diastole and inspiratory 

 changes are prolonged and the toxic effect of an m% solution 

 is counteracted by CaCl m '32 or NaCl m%. 



CaCk solutions are indifferent or depressing to the rate of 

 both cardiac and respiratory activities, but stimulating to the 

 force and slightly so to the blood pressure. M% solutions pro- 

 long systolic and inspiratory phases. 



Solutions of MgSOi are depressing to the respiratory mech- 

 anism and cardiac rate, but at first stimulate heart force and 

 blood pressure. Diastole and expiratory phases are prolonged 

 and the toxic effects are neutralized by m/8 CaCh solutions. 



NaiCOo solutions stimulate heart force and blood pressure 

 and are indifferent to the heart rate and the respiratory mech- 

 anism. Their stimulating effect upon the force of cardiac 

 activity is enhanced when the solution is combined with urea, 

 and like the latter exerts a similar influence upon respiration 

 and heart action. 



