100 VETERINARY MATERIA MEDICA. 



lyzant, anaphrodisiac, diuretic, and emetic. Over- 

 doses irritate the mucous membraDes, causing sneez- 

 ing, severe gastric disturbance, nausea, vomiting in 

 some animals, colicky pains and purgation, the dis- 

 charges being of a greenish color. It reduces tem- 

 perature, presumably by decreasing the blood supply 

 to the tissues. Digitalis slows the heart, but in- 

 creases the force of the heart muscle. It stimulates 

 the cardiac motor ganglia, the inhibitory apparatus, 

 and vasomotor centre, contracting the arterioles, and 

 thereby greatly raising arterial tension. Continued 

 full doses exhaust the irritability of the motor gan- 

 glia and paralyze the cardiac muscle itself. It de- 

 creases the sexual appetite, lessens the contractile 

 power of striped muscular tissue, causes weakness 

 and languor ; the excretion of urea, while at first in- 

 creased, is very soon much diminished. The diuretic 

 action of digitalis is due to its peculiar influence upon 

 the general and renal circulation . It greatly increases 

 blood pressure in the kidneys, as well as the rap- 

 idity of the renal circulation. Toxic doses decrease 

 the reflexes, paralyze the muscles and the peripheral 

 nerves, motor and sensory ; respirations become rapid 

 and feeble ; cyanosis, coma, and convulsions follow ; 

 death takes place by sudden paralysis of the heart, 

 which is arrested in systole (aconite arrests heart in 

 diastole). 



The curative effects of digitalis are brought about 

 in some of the following ways : 1st, By strengthening 

 the heart's action; 2d, by reducing the strength of 

 the heart beats if that organ is acting too powerfully; 



