COLD AND HEAT 717 



nerves, and tends to loosen dry exudations. Agents may be 

 incorporated in tlie inhalation having a sedative, stimulating 

 or antiseptic action. (Vid. "Agents Acting on the Respiratory 

 Organs," pp. 47, 48.) 



The technique consists in placing a bucket containing 

 a boiling mash under the horse's nose, or in pouring cool 

 water over a heated brick or iron in the bottom of a pail.. 

 The practice of tying a bag over a horse's head, and steam- 

 ing him therein, is bad, if the animal is suffering fi'om 

 respiratory troubles, as insufficient pure air is obtainable. 

 A dog may be placed on the seat of a cane bottomed chair, 

 and covered loosely with a sheet over the whole, the steam 

 being generated in a vessel beneath. 



Hot Batlis at a temperature of 98° to 110° F. are imprac- 

 ticable for larger animals. They can be given to the smaller 

 animals in collapse, shock, rheumatism, and to abort cold 

 after exposure. Glowing heat is applied by means of heated 

 metal, and is treated under the section on eounter-irri- 

 tation. 



ACTION OP HEAT CONTRASTED WITH THAT OP COLD. 



The action of intense heat or cold on animal tissue is 

 very similar in effect, producing vasomotor paralysis, con- 

 gestion, inflammation, destruction of tissue and death. Even 

 the sensations to which they give rise resemble each other 

 so closely, that the coolies on first handling ice said they 

 could not hold it because it burned their fingers. Strong heat 

 (115° to 120° F.) contracts blood vessels in underlying parts 

 and overcomes pain and congestion. Heat of this degree 

 approaches cold in similarity of action. A moderate 

 , degree of heat dilates vessels, while cold of like intensity 

 ' contracts them. Moderate heat relieves pain by relaxing 

 tissue, diminishes vascular tension by dilating efferent ves- 

 sels of the collateral circulation, and draining off blood from 

 the congested areas. Moderate cold, on the other hand, 

 accomplishes a similar result in benumbing nervous sensa- 

 tion and lessening the impact of blood in the painful region 



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