USE OF HEAT POST-MORTEM TEMPERATURE. 453 



tion of the liver, heart, kidneys, and muscles begin after 36-48 hours 

 (Litten). 



Cold-blooded animals, if placed in hot air or warm water, soon have their 

 temperature raised 6-1 0C. The highest temperature compatible with life in a frog 

 must be below 40C., as the frog's heart and muscles begin to coagulate at this 

 temperature. Death is preceded by a stage resembling death, during which life 

 may be saved. 



Most of the juicy plants die in half an hour in air at 52C., or in water at 

 46C. (Sachs). Dried seeds of corn may still germinate after long exposure to air 

 at 120C. Lowly organised plants, such as algse, may live in water at 60C. 

 (Hoppe-Seyler). Several bacteria withstand a boiling temperature (Tyndall, 

 Chamberland). 



222. Employment of Heat. 



Action of Heat. The short, but not intense, action of heat on the surface 

 causes, in the first place, a transient slight decrease of the bodily temperature, 

 partly because it retards reflexly the production of heat (Kernig), and partly be- 

 cause, owing to the dilatation of the cutaneous vessels and the stretching of the skin, 

 more heat is given otf (Senator). A warm bath above the temperature of the 

 blood at once increases the bodily temperature. 



Therapeutic Uses. The application of heat to the entire body is used where 

 the bodily temperature has fallen, or is likely to fall, very low, as in algid stage of 

 cholera, and in infants born prematurely. The general application of heat is 

 obtained by the use of warm baths, packing, vapour, insolation, and the copious 

 use of hot drinks. The local application of heat is obtained by the use of warm 

 wrappings, partial baths, plunging the parts in warm earth or sand, or placing 

 wounded parts in chambers filled with heated air. After removal of the heating 

 agent, care must be taken to prevent the great escape of heat due to the dilatation 

 of the blood-vessels. 



223, Increase of Temperature Post-mortem 

 Phenomena. 



Heidenhain found that in a dead dog, before the body cooled, there was a constant 

 temporary rise of the temperature, which slightly exceeded the normal. The same 

 observation had been occasionally made on human bodies immediately after death, 

 especially when death was preceded by muscular spasms. Thus, Wunderlich 

 measured the temperature 57 minutes after death in a case of tetanus, and found 

 ittobe45-375C. 



The causes are : 



(1.) A temporary increased production of heat after death, due chiefly to the 

 change of the semi-solid myosin of the muscles into a solid form (rigor mortis). 

 As the muscle coagulates, heat is produced (v. Walther, Fick). All conditions 

 which cause rapid and intense coagulation of the muscles e.g., spasms, favour a 

 post-mortem rise of temperature (see Physiology of Muscle) ; a rapid coagulation 

 of the blood has a similar result (p. 42). 



(2. ) Immediately after death, a series of chemical processes occur within the body, 

 whereby heat is produced. Valentin placed dead rabbits in a chamber, so that 

 no heat could be given off from the body, and he found that the internal tempera- 

 ture of the animal's body was increased. The processes which cause a rise of 



