ARTIFICIAL INFLAMMATION. 185 



rule. The Author can only recommend, that, unless the new growth 

 cause lameness or is a great eyesore, the time of absorbing it should be 

 left to nature. 



377. Of Irritants used to produced Hyper&mia or inflammation. 



Irritants may be divided into two classes. 

 1st. External Stimulants. 

 2nd. Vesicants. 



373. Action of External Stimulants . 



External Stimulants, or Rubefacients, are those irritant agents which, 

 when applied to the skin, produce redness and superficial inflammation 

 in a comparatively mild form. By the irritation which they produce, 

 they excite the circulation and cause more blood to be brought to the 

 part. Hence they are useful in some cases in accelerating the repair of 

 injured structures. They also give tone to parts, which from debility or 

 other causes have become deficient in vital energy ; and in cases of newly 

 formed tumours, thickening of the skin, and such like ailments, they are 

 useful in exciting the blood-vessels and absorbents to greater energy in 

 taking up and removing the abnormal growths and deposits. 



They are also frequently and beneficially employed on the revulsive 

 principle in hypersemia or congestion in the internal organs. 



A stimulant for instance applied to the sides has often a marked effect 

 in relieving pleurisy. 



Friction, heat, liniment of ammonia, or turpentine, tincture of iodine, 

 iodide of potassium, very mild preparations of cantharides and biniodide 

 of mercury, are the stimulants in common use. 



379. Friction and Heat. 



The mildest and one of the most valuable stimulants is friction by the 

 hand. It is especially useful in mild superficial inflammation, e. g. all 

 horsemen are conversant with its beneficial effects in reducing swelled 

 legs after a hard day's work. 



The objection to it is that it is troublesome and tedious to servants. 



Its effect may be considerably increased by the moderate heat pro- 

 duced by the application of a flannel bandage after the friction. 



380. Liniment of Ammonia or Turpentine. 



A useful stimulating embrocation for application to the skin may be 

 made as follows : 



Strong Water of Ammonia . 1 part. Water . . . 1 part. 

 Oil of Turpentine ... 2 parts. Olive or Linseed 4 parts. 

 This embrocation may be diluted, if necessary, by adding more oil, or 

 its activity may be increased by the addition of more ammonia, 

 or Camphor . 1 oz. Rectified Spirits 4 oz. 



Olive Oil . 1 pint. Strong Water of Ammonia 2 oz. 



