686 GENERAL THERAPEUTIC MEASURES 



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

 could not hold it because it burned their fingere. 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 o& 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 

 by constringing the afferent vessels. Tissue change is 

 increased by moderate heat, but decreased by cold applied 

 locally, or generally in fever. Swelling of tissue is reduced 

 by cold directly ; only indirectly by heat, which may, indeed, 

 increase it. Softening and sloughing of parts, suppuration 

 and "ripening" of abscesses and "cleaning off" of wounds, 

 are facilitated by moderate heat, but hindered by cold. 



Disinfectants, Antiseptics and Deodorants. 



Dlswfectants, or germicides^ are agents which destroy 

 the micro-organisms, causing infectious and contagious dis- 

 eases, fermentation and putrefaction. Antiseptics are agents 

 which prevent the growth d,nd development of the micro- 

 organisms, occasioning fermentation, putrefaction and dis- 

 ease; more especially the micrococci producing suppuiation. 



Deodorizers^ or deodorants, are agents which destroy 

 or counteract a foul odor. They are not necessarily anti- 

 septic or disinfectants. Considerable confusion exists in 

 relation to the terms disinfectant and antiseptic, because the 

 latter is often described as an agent which inhibits the 

 growth, or destroys the life of the micro-organisms of fer- 

 mentation, putrefaction, and disease. This definition makes 

 antiseptics synonymous with disinfectants. The distinction 

 exists, however, according to common usage, that while dis- 



