ORGAN AND BODY SYSTEMS 493 



The severe constitutional reactions from excessive exposure of large 

 parts of the human body to ultra-violet radiation are well known. The 

 gradual building up of the tolerance of the skin through repeated frac- 

 tional dosage, similar to the fractional dosage methods for roentgen 

 therapy, is the basis for its therapeutic use (191, 218). Death has 

 followed too severe and extensive skin damage. This intoxication may 

 have the same mechanism as that following severe burns from steam and 

 other intense sources of radiation in the infra-red spectrum. 



The body has adapted itself to live in equilibrium while receiving 

 large quantities of infra-red radiation, particularly the longer wave- 

 lengths, and is itself a producer of these radiations. Death may be the 

 result of upsetting this equilibrium by the intensive generalized absorp- 

 tion of infra-red radiations from without (artificial fever) or the produc- 

 tion of and failure to radiate excessive amounts of infra-red radiation 

 (spontaneous fever accompanying infections, etc.). Death may likewise 

 follow excessive losses, i.e., exposure to cold. In frostbite a part of the 

 body has been irradiating infra-red radiation at so great a rate that 

 the skin and capillaries and subcutaneous tissues become damaged by the 

 low temperature attained. This is just the opposite type of energy 

 exchange that occurs in a "heat burn," but relatively the same damage 

 occurs and perhaps the same type of intoxication if the damage is 

 extensive enough. 



''Radio-wave" Radiation.— In the last few years there has been 

 considerable interest in the effect of very long electromagnetic waves, 

 so-called "high-frequency" or radio waves. There is considerable 

 evidence to show that the longer waves in the neighborhood of 300 meters 

 (which are produced by the ordinary diathermy machine) produce effects 

 in tissues which are probably related to the transference of this energy 

 into heat. There is some evidence to show that the shorter wave-lengths 

 may have certain specific effects in certain organs of the body, perhaps 

 owing to differences in conductivity, or to electrolyte content, or for 

 other reasons as yet unknown. It is thought that these high-frequency 

 currents may build up excessive temperature gradients in certain organs 

 of the body. Oettingen (254), has published perhaps the most com- 

 prehensive study of the lesions produced by 3-meter waves in the liver, 

 kidney, brain, testes, ovary, and muscle of the mouse. Similar changes 

 have been demonstrated by Schliephake (325). 



Schereschewsky (323) has shown that there is evidence to prove that 

 the shorter wave-lengths (1.0 to 4.69 meters in radio frequencies) do 

 cause specific elevations in temperature of various organ emulsions in 

 \dtro. With the very shortest waves used (1 meter) the comparatively 

 specific heating of these emulsions is maintained and brain, pancreas, and 

 lung retain their property of relatively high heating. Blood serum and 

 plasma show less specific heating than organ tissue; red blood cells heat 



