July 3, 1913] 



NATURE 



467 



ever since. These deaths, he said, were brought 

 about in one of two ways : — 



(1) By direct action, the mechanical effect or disrup- 

 tive action of the electric current on the tissues ; or 



(2) By indirect or reflex action on the nervous 

 centres. 



In the first case death is final ; in the second it is 

 often apparent only, so that the victim may recover 

 if treated by artificial respiration immediately after 

 receiving the shock. Most of the victims of industrial 

 electric accidents had died of asphyxia, he believed. 

 The alternative view that these deaths were due to 

 cardiac failure was first emphasised in 1890 by Tatum, 

 and his is the view very generally held at the present 

 time. It was put on a more scientific basis in 1898 

 by Prevost, who showed that the cardiac failure was 

 the result of fibrillation or fibrillary tremulation of 

 the muscle of the heart, the German Herzdelirium, 

 investigated in 1850 by Hoffa and Ludwig. The 

 extremely well-designed and well-executed experi- 

 ments of Prevost and Battelli (1899) proved the great 

 importance of cardiac fibrillation in causing the death 

 of animals of various kinds when exposed to the 

 passage of electric currents through different parts of 

 their bodies. They also illustrated the various effects 

 oi electric currents of different varieties — alternating, 

 continuous, sudden discharges from condensers and 

 induction coils — on these animals, and proved that 

 when apparentlv killed bv a current at a low voltage, 

 animals might be brought to life again by the shock 

 of the much stronger currents forced through their 

 bodies by the application of high voltages. These 

 authors also demonstrated that while an alternating 

 current with a frequency of 150 alternations a second 

 might be fatal to dogs at an E.M.F. of only 15 to 

 25 volts, when the alternations were increased to 

 1720 a second, no fewer than 400 volts were required 

 to produce death. Using high-frequency currents 

 with from 400,000 to t. 000,000 alternations a second, 

 d'Arsonval (1893) found he could stand the passage 

 of as much as 3 amperes through his body, a current 

 twentv or thirty times as great as that required to 

 kill a human being at the ordinary rates of alternation 

 employed industrially. The experiments of Cunning- 

 ham (1899), d'Arsonval (1910), Weiss and Zacon (191 1), 

 are also worth recording, and have added considerably 

 to our knowledge of death by electric currents. Weiss 

 and Zacon found that chloral anaesthesia gave dogs 

 no protection against electric shocks. With alternat- 

 ing currents given for a few seconds, death would 

 occur when about 70 to 100 milliamperes traversed 

 the thorax with the heart en route ; with continuous 

 currents, death was not caused unless the current 

 was as large as 300 milliamperes, roughlv speaking. 

 If, however, smaller electric currents were adminis- 

 tered for long periods, it was found possible to pro- 

 duce death bv tetanus and asphyxia ; thus currents of 

 35 to jc milliamperes were too small to produce 

 cardiac fibrillation, but after about ten minutes' appli- 

 cation caused death by continued inability to breathe, 

 and slow asphvxiation. It may be noted that Prevost 

 and Battelli found that dogs were not killed bv alter- 

 nating currents as great as 4 amperes at 1200 volts, 

 passed through the body from one hind leg to the 

 other; the reason being that with this arrangement 

 of the electrodes the rate of flow of electricitv through 

 the muscle of the heart was not large enough to cause 

 it to fibrillate. 



One may conclude that living animals of different 

 soecies are killed bv electricity with very different 

 degrees of facilitv. For example, many experimenters 

 have endeavour to electrocute frogs, but all, I believe, 

 without success, whatever the current used and how- 

 ever it may have been applied. The frog survives 

 electric shocks and the prolonged passage of electric 

 NO. 227Q, VOL. 91] 



currents at all sorts of voltages — 10, 100, 1000 volts and 

 more — and shocks from induction coils and charged 

 Leyden jars. The only inconveniences it sutlers 

 appear to be transient pareses or paralyses, and, in 

 the case of strong currents passed for many seconds 

 or minutes, the formation of burns. The frog is thus 

 immune because its heart always begins to beat again 

 regularly and normally after the passage of the elec- 

 tric current, and because its respiration does the same ; 

 and also, as Priestley pointed out in 1767, because 

 "its constitution enables it to subsist a long time 

 without breathing." At the other extreme of the scale 

 comes the dog, which can be killed with certainty by 

 an alternating current of perhaps 15 volts or 60 milli- 

 amperes, if it is applied so as to pass largely through 

 the heart muscle for a couple of seconds only. 



As regards the death of human beings, it may be 

 brought about by electric currents in several different 

 ways. 



(a) There is no doubt that it might be due to pro- 

 longed tetanus of the muscles, which could prevent 

 the performance of respiratory movements, and so 

 lead to death by asphyxia after some minutes. But 

 I am not able to find that it ever has come about in 

 this way as a matter of fact, the victim always being 

 able either to break the contact and interrupt the 

 passage of the current for himself, or to call for help 

 and get the contact broken by somebodv else before 

 asphyxia has occurred in this way. 



(6) In man primary heart failure is undoubtedly 

 the commonest mode of death by electrii currents. 

 The experiments on animals already detailed show 

 that such deaths are due to fibrillation of the ventri- 

 cles of the heart. The fibrillation has been seen occur- 

 ring in the hearts of two criminals electrocuted in 

 America and examined immediately after death 

 (Schumacher) ; a few minutes later the left ventricle 

 was firmly contracted and empty, while the right 

 ventricle and the auricles were relaxed in diastole and 

 full of blood. It is probable that in the adult man, 

 as in the dog, horse, and ape, fibrillation of the heart, 

 once it is established, is irremediable, practically 

 speaking. 



(c) and (d) Death by failure of the respiration while 

 the heart continues to beat, brought about by nervous 

 inhibition, or by failure of both heart and respiration 

 together, is probably not so common in man. There 

 is a great want of evidence on this point ; naturally 

 enough, as the people who are present at deaths by 

 electric shock are generally workmen who do not 

 busv themselves with observations of the pulse and 

 the respiration of the victim. A good many cases 

 have been recorded in which death did not occur until 

 ten, twenty, or forty minutes after the shock had been 

 received, and was then apparentlv due to failure of 

 the respiration to re-establish itself. The experiments 

 upon animals would lead one to believe that such 

 deaths are really due to failure of the respiratory 

 centre in the central nervous system. The post- 

 mortem evidence in such cases should suggest death 

 by asphvxia, and such evidence has sometimes been 

 found after death by electric shock. 



(c) Brief reference may be made to the fact that a 

 good manv cases have been recorded in which the 

 victim of an electric accident has died after a few 

 days or weeks from complications (shock, gangrene, 

 suppuration, exhaustion following extensive amputa- 

 tions) arising out of the injuries caused by the electric 

 current. 



With alternating currents, death has occurred from 

 shocks at voltages as low as 65 volts, and a good 

 many instances of death at such pressures as 100 to 

 120 volts have been recorded. It is only in very ex- 

 ceptional circumstances that these low voltages can 

 cause death; unless the patient's skin is wet and he 



