Du Bois-Reymond's Key Small 216×320 Medium 432×640 Large 691×1024 Download Tiff Original 1619×2400 | (3.7 MB) Description A device for connecting wires from a battery. Keywords lever, switch Galleries Electricity Experiments and Apparatus Source: W. Morrant Baker and Vincent Dormer Harris, Hand-Book of Physiology (Philadelphia:P. Blakiston, Son & Co., 1892) 464 bottom left
