556 BIOLOGICAL EFFECTS OF RADIATION 



spaced at distances of from 1 to 3 in. apart. The two rods, tubes, and 

 condenser CI are mounted on a baseboard in such a manner that the 

 two rods, LI and L2, parallel each other about 3 in. apart. The length 

 of these rods and the capacity of condenser CI may be varied to vary 

 the frequency of the oscillator. Shortening the rods will increase the 

 frequency of the oscillator. The points of connection of X2 and Rl 

 are important. They should be connected at the point of zero voltage 

 along the parallel inductance rods LI and L2. The proper point of 

 connection will vary with the capacity of CI and must be found experi- 

 mentally after the dielectric to be exposed between the plates of condenser 

 CI has been inserted. Once the point is determined, the connections can 

 be made permanent. The method used in locating the point of zero 

 voltage is to pass a small tube containing neon gas along the conductor 

 to a point where it ceases to glow. The voltage at this point is very 

 near the electrical center of the system. 



This circuit, when set up as shown in Fig. 4, will produce oscillations 

 of the order of 60 megacycles and the field of CI provides an excellent 

 exposure point for biological material. 



The above circuits may be, of course, adapted to much more powerful 

 vacuum tubes than here listed, but the standard UX210 tubes, or the 

 like, are suflBcient for most biological purposes. Circuits using tubes 

 up to 34 kw. are fully described in the literature. 



REFERENCES 



1. Baldwin, W. M., and N. G. Nelson. Histological effects produced in albino 

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2. Bennedetti, E. Intorno all'azione del campo electromagnetico oscillante ad 

 alta frequenza su alcuni germi vegetali. Atti R. Accad. Naz. Lincei Rend. CI. 

 Sci. Fis. Mat. e Nat. 4: (7/8): 324-332. 1926. 



3. Carpenter, C. M., and R. A. Boak. Effect of heat produced by ultra-high 

 frequency oscillator on experimental syphilis in rabbits. Amer. Jour. Syph. 14: 

 346-365. 1930. 



4. Carpenter, C. M., and A. B. Page. Production of fever in man by short radio 

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5. Christie, R. V., and A. L. Loomis. The relationship of frequency to physi- 

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6. Gosset, a., a. Gutmann, G. Lakhowsky, and I. Magroxj. Essai de therapeu- 

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7. Headlee, T. J., and R. C. Burdette. Some facts relative to the effect of high 

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 1929. 



8. Horlacher, W. R. An attempt to produce mutations by the use of electricity. 

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9. Hosmer, H.R. Heating effects observed in a high frequency static field. Science 

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10. HuxFORD, W. S. Standing waves on parallel wires. Phys. Rev. Corning, N. Y. 

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