EMPLOYMENT OF COLD. 4 H 



being again warmed, and also the seeds of wheat, oats, peas, etc., exposed for four 

 or five days to a temperature of 192 C. 



The application of a coat of varnish to the skin gives rise to a series of condi- 

 tions similar to those due to reduction in temperature. The varnished skin readily 

 gives off heat outward through radiation, particularly as the blood-vessels of the 

 skin are enormously dilated. Therefore the temperature of the animals falls 

 greatly and some even die. If the reduction in temperature be prevented 

 by applications of heat and of external coverings the animals survive. The blood 

 of such animals as die contains no toxic substances and no retained excremen- 

 titious matters that might have caused death, for other animals injected with 

 such blood remain healthy. In human beings varnishing of the skin appears 

 to have no injurious effect. 



EMPLOYMENT OF COLD. 



Applications of cold to a large part of the surface of the body may be made 

 from the following points of view : 



(a) By means of cold baths or packs of considerable duration to remove large 

 amounts of heat from the surface of the body when the temperature in the presence 

 of fever has attained a dangerous elevation. This effect can be produced in a 

 most lasting manner if the temperature of the bath is at first moderate and is 

 gradually reduced, because the skin is rendered anemic and becomes contracted 

 in consequence of low degrees of temperature, so that a marked obstacle to the 

 dissipation of heat at once arises. Also, the gradually cooled bath is borne for a 

 considerable time. The addition of stimulating substances, as, for instance, 

 salt, which effects dilatation of the cutaneous vessels, favors heat-dissipation, 

 chiefly because the salt-water acts as a better conductor of heat. The reduction 

 in temperature is favored by simultaneous administration of alcohol internally. 

 Also, evaporation of water from the skin, through spraying with aqueous vapor, 

 is adapted for the reduction of the bodily temperature. 



(6) Local external reduction of temperature, as by means of an ice-bag, serves 

 in the first place to cause contraction of the vessels and of the tissues, as in case 

 of inflammation, with simultaneous local abstraction of heat. Whether, under 

 such circumstances, the heat-generating molecular disintegration of potential 

 energy is retarded locally or not is as yet undetermined. 



(c) Local abstraction of heat through the rapid evaporation of volatile sub- 

 stances, such as ether and carbon disulphid, causes anesthesia of sensory nerves. 

 The introduction of media of low temperature into the interior of the body, such 

 as the inhalation of cold air, the ingestion of cold drinks, cold injections into the 

 intestine, the bladder or the genital tract, in part acts locally and in part may 

 cause general abstraction of heat if the action be long continued and intense. In 

 connection with the action of cold it should be borne in mind that the contraction 

 of the vessels and the collapse of the tissues after cessation of the effect are usually 

 followed by increased fulness and turgescence. 



THE TEMPERATURE OF INFLAMED PARTS. 



Heat is considered one of the fundamental phenomena of inflammation, in 

 conjunction with redness, swelling and pain. Nevertheless, the apparent increase 

 in the temperature of inflamed parts is by no means dependent upon increase 

 in the temperature above that of the blood, a condition that has never been 

 observed. In consequence of the dilatation of vessels, which causes redness, and 

 the increased amount of blood flowing through the inflamed parts, as well as 

 through tumefaction of the tissues with well-conducting fluid, the external 

 portions of the body, such as the skin, are usually of a higher temperature than 

 normal, and at the same time they more readily give off heat through conduction. 

 Whether or not increased heat-production takes place in the inflammatory focus 

 itself, perhaps in accordance with the character of the inflammatory process, in 

 consequence of accelerated molecular disintegration, has not as yet been de- 

 termined. 



HISTORICAL. COMPARATIVE. 



Hippocrates born 460 B. C. considered the indigenous heat as the cause of 

 life. According to Aristotle the heart prepares heat within itself and distributes 

 it to all parts of the body, together with the blood. This doctrine, which is pre- 



