VARIATIONS OF THE MEAN BODILY TEMPERATURE. 397 



upon the readily displaceable blood present. When the author, in con- 

 junction with Hauschild, ligated in dogs either the arteries alone or at 

 the same time the axillary and crural arteries and veins, the carotids 

 and the jugular veins, the temperature of the interior of the body rose 

 several tenths of a degree within a short time. Chlorotic and anemic 

 individuals, with pale, bloodless skin, at times exhibit, for the same reason 

 of failing circulation through the skin, elevation of the bodily temperature. 



By means of systematically employed stimuli, which, like cold baths and cold 

 sponging, cause contraction of the muscles and vessels of the skin, the latter may 

 be so invigorated and be maintained in such a state of irritability as to oppose 

 vigorously loss of heat when the body or individual parts thereof are threatened 

 with sudden abstraction of heat. Thus, cold spongings and baths constitute in a 

 measure gymnastics for the muscles of the skin, which under the conditions indi- 

 cated are capable of protecting the body against cold. 



2. Elevation of temperature accelerates the heart-beat, while reduc- 

 tion of temperature diminishes the number of contractions of the heart. 

 Through the action of the heart the blood that is relatively the warmest 

 is pumped from the interior of the body to the surface of the skin ; and 

 in this way it may^ readily give off heat upon the extensive surface. The 

 oftener the same amount of blood courses through the skin, the more 

 will be the amount of heat given off, and the reverse. Therefore, the 

 frequency of the heart-beat is in direct relation to the rapidity with 

 which cooling takes place. Thus, the pulse has been observed to 

 rise to more than 160 per minute in air of an excessively high tem- 

 perature above iooC. This is true not alone of the range of normal 

 conditions, but also of the pathological variations in temperature during 

 the febrile state. C. v. Liebermeister records the following figures for 

 the pulse and the temperature respectively in adults : 



Pulse in the minute: 78.6, 91.2, 99.8, 108.5, IIO T 37-5- 



Temperature in C.: 37, 38, 39, 40, 41, 42. 



If the number of heart -beats is permanently diminished it might be anticipated 

 that elevation of temperature would occur. When the author, in conjunction with 

 Ammon, caused reduction for about one and one-half hours in the number of heart- 

 beats by irritation of the peripheral extremity of the vagus in rabbits, the tem- 

 perature in the rectum fell on the average from 39 to 34-5 C. The enfeebled 

 circulation diminishes also metabolism and oxidation in the body; in fact, this 

 diminution must therefore even over-compensate for the accumulation of heat 

 resulting from the diminished circulation. 



3. Elevation of temperature increases the number of respirations, so 

 that a much larger amount of air passes through the lungs in a given 

 time and in them is raised almost to the temperature of the body. In 

 addition a certain amount of water undergoes evaporation in the expired 

 air with every respiration, and in this way heat is taken up. Therefore, 

 it is to be borne in mind that vigorous respiratory movement materially 

 sustains the circulation, so that the respiration operates indirectly in 

 the manner outlined in 2 . Forced respiratory movement exerts a cooling 

 effect even if air heated to a temperature of 54 C. and saturated with 

 watery vapor is inhaled. 



4. Nature provides many animals with furs during the winter and 

 with lighter covering in the summer. Many animals living in air and 

 water of a low temperature are protected against excessive heat-dissipa- 

 tion by heavy layers of fat. In the same manner man provides for a 

 more uniform dissipation of heat on the part of the skin by means of 

 a difference in clothing for winter and summer. The attitude of the body 



