Sept. 13, 1883] 



NA TURE 



463 



origin of species, the genesis of the colours of flowers, the 

 laws of variation, and other similar subjects. Dr. Miiller's 

 contribution, " Blumen und Insekten," to Schenk's 

 "Handbuch der Botanik," which forms a part of the 

 " Encyklopaedie der Naturwissenschaften," now in course 

 of publication, is an admirable resume of the whole subject. 

 Dr. Miiller died in harness, having fallen a victim to 

 an attack of inflammation of the lun^s at Prad. in Tyrol, 

 on August 25. A. W. B. 



SECOND NOTE ON THE ELECTRICAL 

 RESISTANCE OF THE HUMAN BODY 



"THE fact that the note on this subject inserted in 

 *■ Nature, June 14, p. 151, was copied in externa 

 by the Electrical Review, by the New York Electrical 

 World, and I believe by some other papers, as well as 

 the fragmentary way in which these observations must of 

 necessity be obtained, encourages me to ask for a little 

 further space. This is the more pardonable as the writer 

 in the former paper, in two editorial articles which he 

 founds on my observations, shows ignorance and mis- 

 conception of certain physiological facts involved in 

 them— a misconception the correction of which by myself 

 he does not think fit to publish. 



On August 23, during my visit to the ward, it became 

 obvious that a hopeless and incurable case of renal 

 disease was rapidly sinking. It occurred to me that the 

 patient, being in a state of uraemic drowsiness almost 

 amounting to coma, there would be no inhumanity in 

 adding small electrical currents to the other stimulants 

 which as a last chance we were sedulously administering. 

 I accordingly immersed his feet, which were rapidly get- 

 ting cold, in hot baths of salt and water connected with 

 YVheatstone's bridge. This and the brandy caused a 

 decided rally, and the temperature became normal, viz. 

 98° F. The resistance then taken was 1 100 ohms from 

 one foot to the other. At 3 p.m., however, he rather 

 suddenly relapsed, his hands and nose becoming cold. 

 The following series of observations was taken : — 



2.55 p.m. — temperature 98° 1100 



3° .. 9°o 



35 .. 870 



3-7 „ - 850 



3-12 .. 840 



3.13 .. 820 



3.22 ,, temperature 95° 800 



We concluded that death was imminent, and I ceased 

 the experiment, intending to renew it after the event. 

 But on returning to the ward at 4.36 I found him some- 

 what better and warmer. I applied the large leaden 

 poles, to which I will refer presently, to both feet, so as 

 to reduce the resistance to a minimum. The following 

 remarkable series of resistances was obtained. The 

 thermometer, 1 being found too slow in its action to follow 

 the flickerings of the expiring lamp of life, was not used, 

 the hand applied to the skin being quite competent to 

 detect the great changes of surface heat : — 



4.36 p.m 640 



4.40 ,, 600 



4-45 .. 57° 



4 SO „ (rally) 750 



4-55 .. (relapse) 700 



S-o ,, (great rally) 770 



He was still very cold, but began to ramble in his usual 

 incoherent way (having been slightly deranged for several 

 years), and I therefore left him for the night. On return- 

 ing next morning early I found he had died an hour and 

 a half later. Had I not been greatly fatigued myself, I 

 should have stopped "to secure an observation during 

 post-mortem refrigeration, and before the access of rigor 



1 In the axilla. I hope to use surface thermometers on a future occasion. 

 In my former paper the axillary temperature obv.ously lags behind that of 

 the extremities. 



mortis. As it was I found the corpse in full state of 

 rigidity. We managed to have the testing apparatus set 

 up by 12.30, and without any great disturbance of the body 

 I applied the leaden poles. 



After some preliminary tests I obtained two excellent 

 observations with reversed currents, and found them both 

 exactly alike at 1150 ohms. 



Then came the last experiment with which I now have 

 to trouble you, namely, the question of skin resistance. 

 A tremendous hubbub has been made about this since 

 the time of Duchenne. I believe it has been enormously 

 exaggerated. My anonymous critic of the Electrical Re- 

 view quaintly says : " We most of its " (sic) " know the 

 effect of keeping the feet in salt and water, or water 

 alone " (he does not name soap and water !) " for any 

 length of time. The skin turns white and swells, enlarg- 

 ing the pores (sic) ; indeed nearly the whole of the outside 

 skin is of a spongy nature.'' I need not prolong the 

 quotation, because I simply deny his facts, except where 

 foot- washings have been "like angels' visits," &c, &c. 

 The carefully-prepared epidermis of my patients is en- 

 tirely free from this hypothetical and inaccurately stated 

 cause of error. So I hope is mine ; indeed I feel the full 

 value of the implied limitation of the cautious phrase 

 "most of us." Seriously speaking, it is too bad that an 

 observer of average capacity, and I hope moderate 

 honesty, should be accused of such elementary blunders 

 on mere a priori grounds. Now for tact : Before going 

 to the deadhouse I had provided myself with two silver 

 needles, used for the electro-puncture of aneurisms, 

 and intended to convey a very strong coagulating current 

 from a powerful battery. I inserted one of these to the 

 depth of three inches into the plantar muscles of each 

 foot of the corpse, leaving everything else untouched. I 

 expected the enormous reduction of resistance above 

 named. To my surprise the Wheatstone bridge gave 

 1200 ohms in either direction of current, or 50 more than 

 with large lead and salt-water electrodes. This alleged 

 skin resistance is then only true in the dry state, and is 

 easily conquered by very simple means. Cases of diabetes 

 have been cited in confirmation of this supposed resist- 

 ance, and it has been explained by the peculiar dryness 

 of the skin in this complaint. A patient now in my ward, 

 though a tall emaciated man with long spindle shanks, 

 only gives 1340 ohms from foot to foot, with either salt- 

 water baths, or with the lead electrodes as here described. 

 This is rather under than over the average. 



One word as to the lead electrodes themselves, and the 

 manner of using them. The intelligent and kind lady 

 nurses of our hospital, whom I like to call by their grand 

 old name of " sisters," and who throughout this inquiry have 

 seconded me in the most self-sacrificing way, are in- 

 structed to get ready certain patients for me each morn- 

 ing. The process consists in wrapping both hands and 

 feet in coarse flannel saturated with strong warm brine 

 for an hour before the experiment. Sometimes the pro- 

 cess so graphically described by my commentator occurs, 

 and is dealt with accordingly. I then proceed to wrap 

 the members one by one in a surgical covering of flannel 

 soaked in the same conducting solution. Over this 

 I fold, also in surgical fashion, a strip of thin sheet 

 lead about eighteen inches long, and one and a half 

 inches broad. On the top of all is an ordinary spiral 

 bandage, which moulds the whole to the shape of the 

 limb, and squeezes out superfluous fluid. An indiarubber 

 covered wire leads to my testing table. I may add that 

 each hand or foot is separately deposited on one of the 

 vulcanised rubber waterproof sheets commonly used in 

 the wards, and which I find to be excellent insulators. 

 The first few observations are commonly rejected ; always 

 if they show any suspicion of diminishing. But after 

 even half an hour's maceration this is rarely the case. 

 Between every two observations I put the patient himself 

 on short circuit, to discharge any currents of polarisation 



