L0014189 Augustus Desire Waller: electrocardiogram
Credit: Wellcome Library, London. Wellcome Images
Electrocardiogram: Human heart, diphasic variation, EE; and simultaneous cardiogram, CC. The leads-off to the capillary electrometer were from the mouth to the sulphuric acid, and from the left foot to the mercury. Time, t t, marked 1/10 ths sec.
An introduction to human physiology
Augustus Desire Waller