High Frequency Apparatus* 



OF all the various currents delivered 

 by the modern high frequency coil 

 designed for medical use, perhaps none 

 is of greater moment than that which is 

 known as 



THE D'ARSONVAL CURRENT. 



Lower in potential by thousands of 

 volts than the Tesla current it is never- 

 theless of extremely high pressure. The 

 statistics given by various manufacturers 

 differ, but an average value seems to be 

 in the neighborhood of from twenty to 

 twenty-five thousand volts. At this 

 pressure it sends from one thousand to 

 fifteen hundred milliamperes through 

 the body without the patient feeling the 

 slightest sensation other than one of 

 pleasant warmth. 



The physiological effects of this cur- 

 rent may be noted as an increase of 

 bodily temperature, of excretion and se- 

 cretion, of metabolism, and glandular 

 activity. Probably its most important 

 function, however, is the reduction of 

 blood pressure in cases of arteriosclero- 

 sis. The reports made by physicians who 

 have used the modality in this connection 

 are unanimously favorable, and in many 

 cases the treatment has succeeded where 

 practically everything else has failed. 

 Last, but not by any means least, the 

 treatment has decidedly a sedative effect 

 upon the nervous system. 



The approved method of application 

 is that known as autocondensation. In 

 this treatment the patient forms one plate 

 or conductor of an electrical condenser 

 while a cushion or other insulator sepa- 



*This article is the fifth of a series on high fre- 

 quency apparatus. The first article appeared in the 

 March issue of Modern Mechanics. 



rates the body from the second conductor 

 which is usually a large metallic plate. 

 One terminal of the coil is connected 

 with the patient's body through hand 

 electrodes while the other leads to the 

 plate. 



The current passing through the 

 patient's body is measured on a milliam- 

 meter which is attached to the case of 

 the coil. While this meter is not essen- 

 tial in case of an emergency, still it 

 affords the only means whereby the 

 physician may determine the dosage be- 

 ing administered, and it is, therefore, 

 necessary if the treatments are to be 

 given intelligently. 



The treatment is given either in a 

 special form of chair or else a couch 

 in the upholstering of which the metal 

 plate is incorporated. The chair is pre- 

 ferred by many operators, as in it the 

 patients may recline comfortably without 

 being given the suggestion that they are 

 lying upon an operating table. It is, 

 however, solely a matter of personal 

 opinion with the various physicians 

 whose ideas have been requested. The 

 treatments are equally efficacious in 

 either case. 



That motion picture theatres are re- 

 placing cheap literature is proven by the 

 fact that English educators have found 

 a decrease in the circulation of this read- 

 ing matter, following the increase in the 

 number of motion picture theatres. An 

 American bookseller of renown recently 

 closed up shop, stating that the detri- 

 mental effect of the motion pictures on 

 the selling of books made the business 

 an unprofitable one. 



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