184 THE AMERICAN MONTHLY [August, 



rent could liberate in that time, under the most favorable circumstances, 

 in a sulphuric acid volt-meter, would be less than ^ of a cubic centi- 

 meter (at the temperature of the body). This power is equivalent to 

 the liberation of heat of 0.71 kilogram degrees, centigrade, in one sec- 

 ond, and in ^ second would be able to raise the temperature of a 15 

 kilo dog about the one hundred and fiftieth part of one degree, centi- 

 grade." 



In a letter dated May 27, 1890, Dr. Tatum refers to his article in the 

 Electrical Worlds and to certain facts which they seem to prove 

 as follows ; (some of them have an important bearing on the Kemmlcr 

 enquiry) : 



" 1st. In onl}' three of the twenty-four dogs killed did the heart fail 

 to be arrested distinctly before respiration. In these three no priority 

 could be assigned to the failure of either function. But in the twenty- 

 one other dogs, effective respiration survived the final heart arrest. 

 [Apply this to Kemmler case.] It often began with normal or slightly 

 exaggerated force, and a good rhythm ; then died out more or less grad- 

 ually, but with no final convulsions. Fair inspirations were recorded 

 in several cases as long as four or five minutes after a dose which had 

 lasted only one second, but after which the heart had not executed a 

 single beat that could be detected. 



" 2d. Contrary to what I believe has been the general impression as 

 well as my own, the two cases in which I used currents with 120 re- 

 versals per second, seem to indicate that, if fatal results are at all de- 

 pendent upon the rapidity of alternation, 120 reversals per second are 

 slightly more mischievous than 300. 



" 3d. Alternating currents, as has been longsupposed (though on what 

 seemed to be sufficient evidence) can, for a given time and mode of 

 application, bring about a fatal result with only a fraction of the elec- 

 trical output required by continuous currents. But even here a certain 

 respectable density of current is required. For the least neck density 

 of alternating current that proved fatal was somewhat greater than one- 

 fifth of the least fatal density with continuous currents. 



"4th. The noteworthy fact was developed that under ether, this differ- 

 ence in fatal power between continuous and alternating currents either 

 entirely disappears (4 dogs) or is at least conspicuously lessened (2 

 dogs)." 



The doctor then attempts to account for the difference in fatal power 

 under ether in these words, "it seems to be both a necessary and an 

 adequate explanation, to refer it entirely to the well-known superiority 

 of interrupted or alternating currents as nerve excitants. This prop- 

 erty normally enables alternating currents to add to whatever direct 

 physical action they may in crippling the heart muscle, all the physi- 

 ological energy of the cardio-inhibitory nervous mechanism ; but of 

 course it loses its importance just in proportion as the nervous control 

 of the heart is weakened by ether." 



The fact still to be emphasized is that this superiority of alternating 

 currents is not owing to any part of lesion or paralysis or exhaustion 

 of any part of the nervous mechanism ; but rather to the calling into 

 action of a truly physiological function depends for its manifestations 

 upon the integrity of this mechanism. 



