MATERIA MEDICA AND THERAPEUTICS. 25 



tions, making the heart beat slower, but more regularly and 

 stronger. In large doses they cause irregular action of the heart 

 and death by syncope; digitalis and its alkaloids, strophantus, 

 nux vomica, strychnine, cimicifuga, etc. 



Cardiac Sedatives. — Lessen the force and frequency of the 

 heart's action, they act directly on the cardiac plexus of nerves ; 

 aconite, veratrum, antimony, acidum hydrocyanicum, potassium 

 salts, and chloroform by inhalation. 



Vascular Stimulants. — Dilate the peripheral vessels and in- 

 crease peripheral circulation, thus equalizing blood pressure and 

 preventing or relieving internal congestions. Arnica is the best ; 

 next, ether and alcohol, which also stimulate action of the heart ; 

 nitrous ether (nitrites), nitro-glycerin, liquor ammonii acetatis, 

 opium, ipecac, and heat applied locally. 



Vascular Tonics. — Cause increased contraction of capillaries 

 and arterioles ; they stimulate the vaso-motor nerves, thus raise 

 blood pressure and promote outflow and absorption of lymph, as 

 ergot, digitalis, iron, hamamelis cold, etc., used in cedema and 

 dropsy. 



Vascular Sedatives. — Contract blood vessels, lessen the flow 

 of blood through them and thus limit local inflammation and 

 arrest haemorrhage; ergot, lead acetate, opium, cold, etc. 



AGENTS ACTING ON THE DIGESTIVE TRACT ; 



ON SALIVARY GLANDS. 



Sialagogues. — Promote secretion and flow of saliva and buc- 

 cal mucus. Some act by reflex stii. mlation, as the acids, alkalies, 

 mustard, ginger, and other pungent substances; nauseants also 

 act reflexly from the stomach, these are termed topical sialagogues. 



General Sialagogues. — Influence the glands through their 

 secretory nerves, as pilocarpus, pot. iod., mercury, etc. 



Antisialics or Antisialagogues. — Diminish salivary secretion. 

 Atropine acts by paralyzing the terminal filaments of the secretory 

 nerves ; borax and potassium chlorate lessen it by relieving local 

 irritation, opium and morphine, by diminishing irritability of 

 nerve centers. 



Refrigerants. — Give a sensation of coolness and thereby allay 



