COLD AND HEAT 673 



the stick, powder, paste and ointment. Caustics are some- 

 times employed to stop haemorrhage. (See Styptics, p. 63). 

 The reader is referred to the articles on special agents for 

 further details). 



Suppurants. — Any of the more active counter-irritants, 

 as croton oil, may induce suppuration. Under this head 

 may be mentioned setons and issues of rowel. A seton is a 

 piece of tape or other material, introduced through an in- 

 cision in the skin, and thence under the skin in the connective 

 tissue, and finally out through the skin at a short distance 

 from the point of entrance. The loose ends are then knotted 

 together, and the whole loop is drawn through the wound 

 once daily to keep up constant irritation and suppuration. 

 An issue of rowel is a piece of gauze or tow, which is passed 

 into an incision, where the substance remains, and causes 

 continual irritation and suppuration. To intensify their 

 irritant action, both setons and issues of rowel may be first 

 saturated with cantharides ointment or oil of turpentine. 

 They have been employed in acute diseases of the eye, men- 

 ingitis, " strangles," and in joint and shoulder lameness, near 

 the seat of trouble. Setons and issues of rowel are barbar- 

 ous and dirty, and fortunately are becoming obsolete. 



Cold and Heat. 



Cold. — Cold and heat are only relative terms. As used 

 here, they refer, respectively, to a thermal intensity below 

 or above that of the body. Cold is usually applied by 

 means of water in some form. In veterinary practice we 

 are limited in the employment of cold air, as a medium, to 

 the use of free ventilation and protection of animals from the 

 solar heat. Cool air is especially desirable in the treatment 

 of most febrile affections by lowering temperature and serv- 

 ing as a stimulus to the respiratory, circulatory and nervous, 

 functions generally. Locally, cold causes contraction of the 

 peripheral vessels and muscles of the skin, forcing out fluids 

 from the part and reducing local temperature. This is more 



