546 BIOLOGICAL EFFECTS OF RADIATION 



to obtain synthetic fevers in animals, including man, without the injec- 

 tion of foreign substances. They followed the suggestion of Hosmer (9) 

 who had studied heating effects on salt solutions of various concentrations 

 and on small laboratory animals, and they have contributed a thera- 

 peutic agent of very great possibilities. By proceeding cautiously they 

 were able to treat 25 human patients, obtaining fevers of 104° to 105°F. 

 in 60 to 80 min. The patient was suspended in the field so that the 

 waves penetrated the body from one side to the other; the head was not 

 exposed. They were careful to use the lowest possible current and 

 seem to have avoided entirely the skin and muscle blistering found by 

 MacCreight and McKinley (12) to accompany hard dosage. 



Carpenter is convinced that in spite of the crudities of the present-day 

 apparatus this method of obtaining artificial fevers is not only practical 

 but efficient and will prove of great value to the clinician, physiologist, 

 biochemist and bacteriologist. He also studied the relation of this 

 synthetic fever to infectious diseases in laboratory animals and believes 

 that two desirable effects are obtained by raising the body temperature. 

 First, the increased heat within the body makes a less favorable environ- 

 ment for the multiplication of virus. Second, the heat increases the 

 rate of those chemical processes concerned with the development of 

 immunity and with the general defense mechanism of the body against 

 infectious agents. The general basis for this latter belief is the unques- 

 tionable stimulation of metabolism accompanying an artificial fever. 

 Relative data have been reported by Nasset and Warren (22) who found 

 that in dogs subjected to this exposure there was a depletion of blood 

 sugar and a diminution in the carbon dioxide content of the blood. These 

 phenomena indicate that synthetic fever obtained by means of the high- 

 frequency field leads to a markedly increased metabolism. 



In this connection both Schliephake and McKinley found that 

 attempts to prolong synthetic fevers in mice for more than 12 hr. result 

 in a profound disturbance of the body-temperature-regulating mechanism, 

 and after continued treatment the body temperature tends to fall below 

 normal. Animals so treated often die. It is believed that only synthetic 

 fevers of very short duration are safe. 



The factor of internal heat observed in these experiments has been 

 obvious in all work with the high-frequency field. It is, after all, the 

 effect one would expect from an a priori examination of the nature of 

 the electric field. Kahler and his coworkers (11) pointed out that the 

 photochemical effect in the high-frequency field is negligible. 



AN EFFECT OTHER THAN HEAT 



Internal heat, then, as a major factor is admitted by all workers who 

 are using this radiation; but there is a growing conviction on the part of 

 several that heat, as such, is not the only factor involved — that there 



