For whom bell toils: medical imaging by telephone.

The use of the induction balance, which was invented by Alexander Graham Bell to cancel out line interference on his telephone, to determine the location of bullets inside the human body is discussed. Experiments conducted to locate a bullet in the body of US President Garfield, who had been shot by an assassin in 1881, are described. The trials on Garfield were unsuccessful, but the approach was later perfected by Bell.

The inductorium: the stimulator associated with discovery.

The inductorium, or induction-coil stimulator, introduced in the late 1830s, provided a means for obtaining repetitive stimuli; thereby allowing the discovery of new properties of excitable tissues. Major physiologic discoveries with the inductorium were tetanic contraction of skeletal muscle, inhibition of the heart, the role of vasomotor nerves, and cortical localization. In the hands of clinicians, it was used to diagnose neuromuscular disease and to produce artificial respiration with body-surface electrodes.