Abstract
The observations here reported were designed to test a method for injuring or destroying specific, localized areas of living tissue at a distance. The underlying principle of the method was the known heating effect upon metal of an electromagnetic field. The method consisted of implanting in the target areas of cats and rats small pieces of metal and then placing the whole animal in an electromagnetic field.
Source of the Electromagnetic Field. The source used for developing the electromagnetic field consisted of a quenched gap high frequency generator designed to operate from a 60 cycle power supply, requiring several kilowatts when operating at maximum output.
The field on the high frequency or secondary side of the generator was built up by means of a water cooled inductance, wound on a tube of bakelite of a size sufficient to accommodate the experimental animal and to prevent direct contact with any part of the winding during treatment.
In those experiments reported here, the frequency of the field was fixed at 400,000 cycles per second, relatively low compared with the frequencies used in diathermy. The secondary current, or that creating the field, reached values as high as 122 amperes.
Tests With Various Metals. After some preliminary experiments had demonstrated the feasibility of the method, tests of 3 metals were carried out in order to discover their relative suitabilities for this purpose. It was found that magnetic iron was better than cold rolled steel and that both were very much more useful than silver.
The difference between metallic iron and cold rolled steel is illustrated by their relative speeds in melting paraffin under the conditions of the experiment. Plates of metal, 3 × 3 mm were imbedded in paraffin with a melting point of 55°C, so as to be surrounded by about 3 mm of paraffin on all sides.
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