118 BOTANICAL GAZETTE [SEPTEMBER 
move toward the positive pole. The particles of methyl violet, 
magdala red, lead, and bismuth move toward the negative pole. 
REvss (20) of Moscow seems to have been the first to discover 
the phenomenon of electrical migration variously known as electro- 
phoresis or cataphoresis. He found that when two poles of a 
battery are immersed in a liquid and separated by a membrane the 
liquid will move through the membrane toward one of the two 
electrodes, and consequently the levels on the two sides of the 
membrane will not be the same. He discovered furthermore that 
while water moved toward the cathode, particles of various sub- 
stances suspended in the water moved toward the anode. 
That not all liquids migrate toward the cathode was first 
announced by QUINCKE (19). Oil of turpentine and absolute ethyl 
alcohol ‘‘that contained an organic impurity”’ migrated toward the 
anode. That the nature of the containers plays a part in deter- 
mining the direction of flow was shown by the fact that in a glass 
tube lined with sulphur, oil of turpentine changed about in its 
direction of flow and migrated toward the negative pole. Water, 
however, was uninfluenced by the sulphur-lined tube and migrated, 
as in glass, toward the negative pole. The inhibiting influence of 
electrolytes on the movement of particles in suspension in an 
electric field was discovered by JiiRGENSEN (11). Suspensions of 
carmine in solutions of sulphuric acid, copper sulphate, and sodium 
chloride gave no evidence of movement when subjected to the 
current. On dilution of the easily conducting solutions, the par- 
ticles again responded to the current. 
That water, when absorbed by a semisolid material, will migrate 
was shown by Du Bots-REyMonp (7). Incidental to this work was 
the invention of the non-polarizable electrode, which consists essen- 
tially of a short glass tube plugged at one end by moist kaolin, or 
by a camel’s hair brush. Above the kaolin the tube is filled with a 
solution of ZnSO, into which dips an amalgamated zinc rod which 
is connected with the source of current. The semisolid used by 
Du Bois-REYMOND was a cylinder of egg albumin. The non- 
polarizable electrodes were brought in contact with the ends of 
the cylinder, and in passing the current the end in contact with the 
positive electrode developed a constriction a short distance from 
