MEDICINES WHICH ACT ON TISSUE CHANGE 453 



show condition by their aid, will often fade or lose his bloom when after 

 long use they are discontinued. 



The glossy skin beloved of horse dealers and exhibitors is often the 

 result of a course of arsenic, antimony, sulphur, and nitre, which are chiefly 

 employed on account of their action upon the skin. Sulphuric acid (oil of 

 vitriol) is the chief agent of the teamster, who too often relies on such mix- 

 tures to impart sleekness to the coat, which can only be otherwise obtained 

 at considerable expenditure of manual labour. 



Arsenic. — The preparations used in veterinary medicine are white 

 arsenic (arsenious acid), solution of arsenic, and the arseniates of iron and 

 copper. This drug is a deadly poison, and should not be administered for 

 any purpose save by the advice of a qualified veterinary surgeon, and in no 

 case upon an empty stomach, as it is irritating to the mucous membrane of 

 the alimentary canal. Notwithstanding this, carters and others are in the 

 habit of giving large doses after fasting, for the expulsion of worms, and 

 sometimes this has fatal consequences. 



As an alterative, arsenic is given in small doses gradually increased. If 

 given in a ball, the dose can be accurately apportioned and controlled, and 

 combined with an alkaline solvent; but the practice of giving it as a 

 powder is dangerous and objectionable, inasmuch as it is liable to fall to 

 tlie bottom of the manger and to accumulate there, later to be taken as a 

 fatal dose when that receptacle is licked clean after a bran mash or other 

 moist food. The solution Liquor arsenicalis, or Fowler's solution, is the 

 most satisfactory preparation, as it may be given in the food without incur- 

 ring the risk referred to above. When arsenic has been administered for 

 some considerable time, and it is desirable to discontinue its use, the dose 

 should be gradually reduced and not suddenly discontinued, a remark that 

 applies more or less to all altei'atives. 



Action and Uses of Arsenic. — Externally it is employed as a 

 caustic in the form of a paste to destroy warts and other growths, and in 

 weak solution as a parasiticide. Besides its alterative action when given 

 internally, it is sometimes employed as a stomachic or stimulant to the 

 stomach to aid digestion. It combines with the blood corpuscles, and the 

 more readily when in combination with iron. All the organs and tissues of 

 the body receive it from the blood, and for a time it remains incorporated 

 with them; but it is eventually eliminated by the liver, the kidneys, and 

 the skin, through the medium of their respective secretions, the bile, the 

 urine, and the sweat. 



Intractable skin diseases, especially those of a constitutional character, 

 may often be treated successfully with arsenic given in the food. Where 

 animals are known to suffer from periodical outbreaks of skin disease, a 



