September 13, 1917] 



NATURE 



25 



>articular case may be suffering- from, and an 

 lopsy may not reveal the cause of death. An 

 important point to decide, so far as practicable, 

 is what voltage is to be regarded as dangerous, 

 stated above, the resistance of the skin may 

 V greatly. But, according to Jellineck, 100 to 

 I volts may usually be handled with impunity ; 

 ) to 500 volts are dangerous ; anything above 

 volts nearly always causes death. It has been 

 1 that o"i ampere is fatal, but this is probably 

 < upper limit of safety, and many persons, espe- 

 cially alcoholics, are very susceptible. The time 

 of exposure naturally plays an important part, so 

 that a short contact may be innocuous, while 

 a longer one is fatal. This is partly due to the 

 fact that the resistance decreases during the 

 passage of the current, so that more and more 

 is sent through. Cases where one of the mains 

 is earthed are especially dangerous if contact be 

 made with the insulated main. It appears, how- 

 ever, that the electrostatic capacity of a large 

 circuit may render contact with a completely in- 

 sulated alternating current dangerous. 



The precautions to be adopted are detailed in 

 the fifth chapter. These are partly of the nature 

 of notices of danger placed in the neighbourhood 

 of live conductors and instructions to workmen 

 employed where there is risk of contact. All live 

 conductors should, if possible, be placed out of 

 reach, and all parts liable to obtain static charges, 

 such as the outer cases of transformers, should 

 be earthed. Since it is very rare that hoth. mains 

 come into contact with the body, a sufficient pro- 

 tection, up to 500 volts, is usually found in insu- 

 lating- gloves and such like. In the case of alter- 

 nating currents special danger is incurred when 

 the insulation between the primary and secondary 

 coils of a transformer breaks down, or, in general, 

 whenever a low-tension circuit becomes connected 

 with one of high tension. Various methods of 

 automatic connecting to earth, when this happens, 

 are described. The advantag^es of connecting one 

 main of the secondary circuit permanently to earth 

 are fully discussed, and the means of making 

 good earth contacts pointed out. Where there is 

 a water main this forms the best of such con- 

 nections. 



The final chapter deals with the treatment of 

 accidents. Burns require the usual dressing's and 

 present no special difficulties. On the other hand, 

 the numerous effects of the passage of a current 

 through the body make it difficult to know what 

 has actually happened. The most obvious result 

 is a cessation of respiration and of the beats of 

 the heart. It is almost impossible to say which 

 is the primary cause, since either involves the 

 other. But the tteatment is the same, namely, 

 artificial respiration applied as soon as possible, 

 without waiting for removal or for the arrival of 

 a medical man. The report of the American 

 Commission on the best method finds that 

 Schafer's is to be preferred. One of the most 

 important points in its favour^ is, perhaps, not 

 ' sufficiently insisted on : that is, that it can be 

 carried on for a long time without fatigue to the 

 ,1,^ NO. 24Q8, vol. IO0I 



operator. The value of this is shown by some 

 of the cases mentioned, especially one in 

 America, where the patient did not recover until 

 artificial respiration had been carried on for six 

 hours. Some other methods of artificial respira- 

 tion are described, but, with the exception of the 

 old Sylvester method, they are ineffective and so 

 far mischievous, since they waste time during 

 which an effective method might have been used. 

 If compressed oxygen is available, advantage will 

 be grained by arranging- that the gas drawn in 

 by inspiration shall consist of oxygen. As con- 

 cerns the use of apparatus for insufflation of 

 oxygen, in place of the mechanical movement of 

 the chest, they are no doubt valuable, if at hand. 

 But this is rarely possible, and M. Rodet rightly 

 insists that a less effective method may be suc- 

 cessful if used dt once, where a more perfect one 

 may be useless if it involves only a few minutes* 

 delay. 



The heart sometimes enters into fibrillary con- 

 traction. If this is the case with the ventricle, 

 no means yet known are capable of restoring- it. 

 It seems that a more direct massage of the heart 

 may in some cases be of use, if it can be done 

 without interfering- with the artificial respiration. 

 Intravenous injections of saline solutions contain- 

 ingf adrenaline may also be given. By this means 

 a better supply of blood to the heart and brain is 

 brought about by the rise in arterial pressure. It 

 j is to be remembered that Schafer's method of arti- 

 I ficial respiration involves, more or less, a rhyth- 

 I mical compression of the heart. 



But, even when natural respiration has re- 

 turned, the patient must be watched for some 

 time, since he may cease breathings again and 

 require renewed artificial respiration. He should 

 be kept warm from the first and, after natural 

 breathingf has returned, may be given hot coffee. 

 But on no account must liquids be given until 

 that time. Secondary complications, such as 

 paralysis or renal affections, may cause death days 

 or weeks after the accident. 



The author concludes that, in any case, pre- 

 vention is better than cure, and that every means 

 of avoiding the chance of contact with live con- 

 ductors should be adopted, both for workpeople 

 and for the public in general. 



The book is written with the usual lucidity of 

 French scientific works and should be in the hands 

 of everyone likely to have to deal with the results 

 of exposure to electrical currents. 



W. M. Bayliss. 



IMPERIAL MINERAL RESOURCES 

 BUREAU. 



AS was briefly announced in Nature of June 7 

 (p. 289), the Minister of Munitions has 

 appointed a committee to prepare a scheme for 

 the establishment of an Imperial Mineral 

 Resources Bureau, to be located in London. This 

 is obviously the first step towards carrying out the 

 recommendation of the recent Impierial War Con- 

 ference : "That it is desirable to establish in Lon- 

 don an Imperial Mineral Resources Bureau, upon 



