542 BIOLOGICAL EFFECTS OF RADIATION 



experimenter has for the time being confined his researches to a range of 

 wave-lengths of from 1 to about 100 meters. 



The biologist applies this radiation by use of a tuned circuit excited 

 by electrical oscillations of very high frequency (3,000,000 to 300,000,000 

 cycles per sec), the exciting oscillations being generated by a three- 

 electrode vacuum tube. Not being able to obtain this form of energy 

 in sufficient amount unless the very closest possible approach is made 

 to the radiating source, the biologist exposes his experimental material 

 in a part of the radiating circuit itself. A part of this tuned circuit (as 

 will be described in another part of this paper) is a high-frequency electric 

 field which is present between the plates of a condenser. With the 

 modern vacuum tube and associated circuits it is possible to provide in 

 this space (in which exposures are to be made) an electric field of contin- 

 uous wave current emitted sharply at the wave-length to which the cir- 

 cuit is tuned. 



Biological material in this situation, that is, insulated between the 

 condenser plates of the circuit, is subjected to an electrical stress. The 

 excitation circuit shifts the polarity of the condenser at the frequency 

 employed, and consequently a very rapidly oscillating field is provided. 

 No free electrons from the external circuit can enter, nor can any elec- 

 trons flow out of the experimental material; but there may take place 

 a displacement current in which electrons in the molecules of the material 

 being exposed are stressed first in one direction and then in the other. 

 Free electrons would tend to pass from molecule to molecule, and the 

 molecules themselves, if bipolar, as indicated by recent researches in 

 physics, would tend to rotate in response to the changing potential of 

 the field. 



Schereschewsky points out that this situation (an animal between 

 the condenser plates) in equivalent electric circuit presents at least 

 two possibilities. The first and more probable possibility is that the 

 system (see description of apparatus) may be regarded as two condensers 

 in series connected by a resistance, the first condenser being formed by 

 one plate of the metallic condenser and one side of the body surface, the 

 intervening glass acting as a dielectric. The second condenser is formed 

 in similar fashion by the other side of the body, the other plate of the 

 metallic condenser, and the intervening glass. Between these two con- 

 densers in series is the bulk of the body tissue of the animal acting as a 

 connecting resistance. The other possibility in equivalent electric circuit 

 is that the animal's body may act in the circuit as a dielectric of poor 

 quality. In this case the electrical equivalent would be a condenser 

 shunted by a resistance. 



Such an intimate "stirring" of the fundamental constituents of matter 

 might well be expected to affect very profoundly the complex and deli- 

 cately balanced structure of living material, and such the biologist finds 



