330 THE OUTGO OF ENERGY 



is not injured by the current ; its tissues are 

 not easily excitable by electricity, though they 

 respond readily to mechanical stimulation. 



APPARATUS 



Normal saline. Bowl. Towel. Pipette. Glass plate. 

 Sharp knife. Two dry cells. Four non-polarizable. elec- 

 trodes. Simple key. Capillary electrometer. Co-ordi- 

 nate paper. Millimetre scale. Inductorium. Electrodes. 

 Thirteen wires. Porcelain dish. Muscle clamp. Muscle- 

 lever. Stand. Cork. Rheochord. Normal saline clay. 

 Filter paper. Wheel interrupter. Candle-wick. Electro- 

 magnetic signal. Pole-changer. Bent hooks. Black paper 

 (stroboscope). Moist chamber. Large and small brass 

 electrodes. Cotton. Common salt. Two beakers. Satu- 

 rated solution of zinc sulphate. Cotton thread. Frog 

 board. Heart-holder. Black box for covering retina. 

 Bunsen burner. Glass slide. Cork clamp. Frogs. 



