1896-97.] Prof. M‘Kendrick on Weak Electric Currents. 251 
Note on the Sensitiveness of the Skin to Weak 
Electric Currents, as compared with the Sensi- 
tiveness of a Telephone to the same Currents. 
By John G, M ‘Kendrick, Professor of Physiology, Univer- 
sity of Glasgow. 
(Read February 1, 1897.) 
On 7th December last, I showed to the Society a method by 
which the skin might be stimulated by electric shocks from an 
induction coil corresponding in rhythm and intensity to the 
notes and chords of music given off by the phonograph. The 
pressures from the disk of the phonograph act on a variable 
resistance microphone transmitter, and the current passing through 
Description of Diagram.— a, phonograph disk ; b, variable 
resistance ; c, Obach’s dry cell ; d, key ; e, primary, and 
/, secondary coils of induction machine ; g, resistance 
box ; h , i, glass beakers, containing salt solution and slips 
of platinum ; t, telephone. 
the latter also passes through the primary coil of an induction 
machine. From the secondary coil wires pass to two strips of 
platinum, immersed each in a beaker containing *75 per cent. 
