

856 HENRY A. MATTILL 



the control of the autonomic nervous system. The physical regulation 

 governs heat losses by a variable cutaneous circulation and the activity 

 of the sweat glands. The chemical regulation controls heat production 

 through increased muscular activity. By means of the protection of 

 clothing, man aids these methods of regulation through surrounding him- 

 self with an atmosphere but little cooler than the body. While the internal 

 temperature of the body is about 37.5C. the temperature of the skin is 

 usually only a few degrees below this, such that a bath at about 34 C. 

 neither adds to nor subtracts from the body supply of heat. Such a bath 

 is called an indifferent bath. This indifferent point may vary with differ- 

 ent individuals and in different conditions and has been given variously 

 from 34.2 to 37. 



There is fairly general agreement that exactly indifferent baths have no 

 demonstrable influence on metabolism, whatever their duration, but while 

 the effect of such baths or of those slightly above or below can not be meas- 

 ured in terms of metabolism, their importance in the treatment of many 

 forms of insanity and in psychoses must be mentioned (Beyer). The con- 

 tinuous flow bath at indifferent temperature produces relief from nervous 

 symptoms and frequently exercises a more powerful and effective sedative 

 action than any drug. Such effects are secondary to those produced on 

 metabolism itself but they far outweigh the latter in importance. 



Cold Baths 



The immediate effect of a cool or cold bath is a contraction of the 

 cutaneous blood vessels, more or less proportional to the degree of cold, 

 whereby loss of heat by radiation, conduction and evaporation is dimin- 

 ished. Depending on the extent of the cold, respiration also becomes more 

 deep and rapid and muscular activity is excited reflexly. These responses, 

 especially the muscular contractions known as shivering, are an attempt 

 to produce more heat, loss of which from the body has been compensated 

 to a slight degree only by physical regulation (Loewy). If cold application 

 is prolonged, heat production fails to keep pace with loss, anemia gives 

 place to hyperemia which unless it is only local (as from an ice bag) 

 produces a rapid fall in body temperature and the circulation begins to 

 fail. If, however, the cold is withdrawn before this time a ^secondary 

 hyperemia, the "reaction" in hydrotherapy, is secured and by thus prem- 

 aturely breaking off the physical- regulation, the stimulus due to the tem- 

 perature change is artificially enhanced. In the opinion of Matthes the 

 stimulus due to a short exposure to cold is probably of small importance 

 compared with the effect of the "reaction." According to Fox the whole 

 effect of baths of .every description is founded on the power of reaction 

 possessed by the organism. The extent of the reaction is diminished 



