GLOSSARY 289 



conducts electricity was discovered by Stephen Gray ; 

 electricity in plants was discovered by Sir John 

 Burdon-Sanderson (nearly sixty years ago). So- 

 called "animal electricity" has received much atten- 

 tion, with names such as Galvani, Peltier, Du 

 Bois-Reymond, Tigerstedt, Ewald Hering, and Au- 

 gustus Waller identified with the investigations. 



Electrochemistry. One of the branches of physical 

 chemistry. It treats of chemical changes that deter- 

 mine or are determined by electrical processes or 

 phenomena. 



Electrokinetic. Relating to or caused by elec- 

 tricity in motion. 



Electrolysis. The decomposition of a chemical 

 compound by means of an electric current. 



Electrolyte. A substance (acid, base, salt) that, 

 when present in solution, conducts the electric cur- 

 rent. 



Electrolytic Dissociation. The dissociation of an 

 electrolyte into ions when it is dissolved in water or 

 certain other liquids. See Electrolyte. 



Electrolytic Solution Pressure. A term used to 

 designate the force by virtue of which metal ions 

 pass into solution when a metal is immersed in pure 

 water. The metal is negatively charged and the 

 solution positively charged. At the interface, or 

 boundary of the metal and the solution, a layer of 

 positive and negative charges (electrical double 

 layer) is formed. 



Electron, The. Historical. The first instance on 

 record when electricity was thought to be atomic is 

 that of Thales of Miletus {ca. 600 B.C.) who ob- 

 served the effect of the rubbing of amber. Benjamin 

 Franklin, to whom we owe the terms "positive" and 

 "negative" to designate the two kinds of electricity, 

 was perhaps the first in modern time to advocate 



