4 S ° 



NATURE 



[July io, 1913 



requires currents of large magnitude, and 

 ore requires that the ionic effects shall be 

 1 to a minimum. The currents of high 

 frequency answer these requirements. With them 

 the duration of each wave of current is so brief 

 thai the ionic movemeni set up is imperceptible; 

 the displacement which ihe ions undergo in the 

 very small fraction of a second for which each 

 1 ontinues is minute and does not strain the 

 elasticity of the protoplasm, if one may make use 

 of such a phrase. On this account the currents 

 employed may reach an ampere or more, and 

 the usual ionic effects of currents, such as pain 

 and muscular contraction, are absent. The thermal 

 effects become manifest in proportion to the 

 magnitude of the currents employed. The practical 

 recognition of the thermal action of high-fre- 

 quem y currents remained long unnoticed, in spite 

 nl the great popularity enjoyed by- high-frequency 

 treatment some time ago. Somerville may be said 

 to have awakened medical practitioners to its 

 possible importance by his paper in 1906 on the 

 effect of high-frequency currents in raising the 

 surface-temperature of the body. 



When we look back upon the cases which have 

 been reported as cured by currents of high fre- 

 quency we may now recognise that a large part 

 .ii them can be justly attributed to thermal actions 

 and the vasomotor effects secondary to these. The 

 circulatory effects, the relief of various states of 

 spasm and congestion, and of painful affections 

 of the joints, of neuritis and neuralgia come into 

 this category. An improvement in the lymph 

 circulation due to the warmth would account for 

 the results obtained with high-frequencv currents 

 in certain local infections and inflammations. 



In another section of high-frequencv treatment, 

 namely that of the use of the effluve or of showers 

 of sparks in cutaneous affections, we also have to 

 deal with thermal effects, intense but minutely 

 localised, though it is possible that in these cases 

 there may be another factor concerned, namely the 

 influence of the ozone, and of the nitric acid 

 vapours which are associated with luminous 

 electrical discharges. 



We now perceive that in high-frequency applica- 

 tions we have an agent for the direct warming 

 of the tissues traversed by the current, and that 

 the future development of high-frequency treat- 

 ment will be based upon these thermal effects. 

 The progress which has been made by Nagel- 

 schmidt and others with the large currents ob- 

 tained from the modern type of high-frequency 

 apparatus, which uses sustained oscillations, and 

 is known under the name of diathermy, serves to 

 emphasise this aspect of high-frequencv currents. 

 Duddell's singing arc in a modified form is used 

 for the production of the oscillations in the dia- 

 thermv apparatus. 



1. in electro-diagnosis we are on the 

 threshold of another change. The long and 

 1 itirnt work of many investigators upon the use 

 denser discharges has begun to bear fruit, 

 and it is clear that from the condenser we gain 

 greater information than the induction coil and the 

 NO. 2 2 8o. VOL. 91] 



galvanic current can give us as to the degree of 

 abnormality in muscle in cases of paralysis, while 

 the process of testing with condenser discharges 

 is simpler in application and far less painful to 

 the patient. Whereas hitherto neurologists have 

 been content to divide muscles into two categories, 

 those with "normal" reactions and those with a 

 reaction of degeneration, the condenser method 

 now permits the recognition of a considerabl 

 number of intermediate degrees. The method i 

 based upon the observation of the minimum 

 capacitv needed to provoke the muscular con- 

 traction. As a muscle deviates from the normal' 

 standard it comes to need waves of longer and* 

 longer duration in proportion to its degree of 

 damage, and these waves are best obtained by 

 using a series of condensers of progressively in- 

 creased capacity, charged from a constant source 

 and discharged through the patient. Many ol 

 the muscles formerly described as normal because 

 they had not lost the power of responding to 

 induction-coil currents can now be seen to present 

 different degrees of deviation from the normal, 

 and those classed together as showing a reaction 

 of degeneration can also be divided into distinct 

 groups. Working- with 100 volts to charge the 

 condensers, one can use a series of ten or twelve 

 capacities, ranging from o'oi to 2*0 microfarads, 

 and can find muscles showing their initial con- 

 traction at almost every step in the scale. 



The work of Houdet de Paris, Hoorweg, 

 Zanietowski, Weiss, Doumer, Cluzet, and of 

 many other patient students of condenser dis- 

 charges must be gratefullv acknowledged in this 

 connection. They have gradually brought their 

 methods through the laboratory stages and ren- 

 dered them suitable for everyday clinical work- 

 so that electro-diagnosis in the immediate future 

 is sure to develop in the direction of condenser 

 discharges, and the old method with induction 

 coil and battery current may be regarded as 

 obsolete. 



With these evidences of progress the electro- 

 therapeutist of to-day can feel more hopeful. He 

 is no longer tied to the old routine methods, and 

 sees before him the commencement of a thera- 

 peutic method based upon the laws of chemistry 

 and physics. H. L. J. 



INTERNATIONAL FISHERY INVESTIGA- 

 TIONS. 1 

 ~PHE series of reports now under review on 

 A the work of the International Council for the 

 Study of the Sea furnishes evidence of continued 

 activity in many branches of the work. One of 

 the most interesting new features is described in 

 the hydrographical bulletin, which contains an 

 account of a series of observations on tempera- 



1 Consed Permanent International pour I'Exploration de la Mer. Bulletin 

 Hydrographique pour lAnnee Inillet iQio-Hrn ion — Bulletin Plank- 

 tomnue pour les Annees 1908-11.— Publications de Circonstance, No. 62.— 

 Rapports et Proces-Verbaux des Reunions, vol. xiv., lOio-n.-Hullelin- 

 Stat.st.que des Peches maritimes des Pavs du nord de I'Eurore. vol. vi., 

 pourl annee iqoo L — Investigations on the Plaice. General Peport by Dr. 

 Fishery and Protective Measures (Preliminary brief 

 portant points of the Report).— Prr ces-Verbaux des- 

 ;, Copenhaa;ue, Septembre 1912. 



F. Heincke. I. Pla 



summary of the most ._ r 

 Reunions du Conseil et des Se 



