DRUGS WHICH ACT ON THE HEART AND BLOOD-VESSELS 463 



The most recent and effectual remedies for dilating the blood-vessels 

 all over the body are the nitrate of amyl and nitro-glycerine. The former 

 has to be inhaled to produce its effect, and the latter is given internally. 

 They are used for heart spasm (angina pectoris), and in asthma, broken 

 wind, and convulsions. In poisonous doses paralysis of both motion and 

 sensation results, and death by cessation of respiration. 



We have now to consider those drugs which are credited with pro- 

 ducing the opposite effects upon blood- 

 vessels. 



Ergot of Rye (fig. 429) is one 



of the most active drugs in causing 

 contraction of the small blood-vessels 

 in man and some of the domesticated 

 animals; but its action upon horses is 

 uncertain, and even in large doses 

 its effects are not so marked as upon 

 dogs. It probably has some medi- 

 cinal value, and is therefore mentioned 

 in this connection. It is thought 

 by some to be the cause of abor- 

 tion when taken as ergotized grasses, 

 but experiments in 'which pregnant 

 animals have been dosed with large 

 quantities do not bear out the theory. 

 It is given to mares after parturition, 

 with a view to induce contraction of 

 the womb, and has been recommended 

 for inflammation of the coverings of 

 the brain and spinal cord. 



Witch-hazel (Hamamelis vir- 



ginica). This is a shrub (fig. 430) growing freely in many parts of North 

 America. From the flowers and dried bark are made the medicinal pre- 

 parations in use. These are extract, powder, distilled extract, and ointment. 



Uses. For haemorrhage, witch-hazel is used both as an external ap- 

 plication and an inward remedy. It is applied as a lotion to arrest bleeding 

 from wounds, and given for haemorrhage from the lungs and abdominal 

 organs. For piles in young foals it is an excellent remedy, and is 

 employed both topically and internally. The dry extract, which has not 

 been officially recognized in the Pharmacopoeia, makes an excellent oint- 

 ment for soft granulating wounds with a tendency to bleed.- The dilute 

 lotion is sometimes applied to inflamed eyes. 



Fig. 430.- Witch-hazel (Hamamelis virgmica) 



1, Hamamelis (portion in flower). 2, Segment of 

 flower. 3, Bark with cork. 4, Bark with cork 

 removed. 5, Bark, inner surface. 



