3lH Uhler cmd Browning — Electrolysis and 



are probably closely related to the following phenomena. As 

 soon as the current is interrupted the trees react on the elec- 

 trolyte and give off gas bubbles copiously. When kept in ice 

 water they evolve a little gas for a day or two, the rate of reac- 

 tion decreasing as the time of immersion increases. The evo- 

 lution is more rapid in water at 23° C. When a tree (of any 

 previous history) is plunged into boiling water a relatively 

 large amount of gas is suddenly liberated with a hissing sound 

 as the parts of the structure coalesce into a mixture of bright 

 liquid globules and the colored compounds. 



The metal deposited in the liquid state has properties similar 

 to those of the trees. When a globule is allowed to remain dn 

 the electrolyte (in the spoon) for ten or more hours the surface 

 loses its high reflecting power and becomes coated with 

 a blackish skin. The brilliant gallium shot (conveniently 

 obtained by dropping a fresh globule into cold water and then 

 hastening solidification by kneading the molten metal with a 

 thin glass rod which has previously become contaminated with 

 the solid phase) gradually acquire a dark coating when kept in 

 air, water, ethyl alcohol, and kerosene. It was also observed 

 that some gas was evolved in each of the liquids, especially in 

 distilled water. In fact, on one occasion the cork stopper of a 

 vial, which had contained a pile of shot under water for several 

 days, was blown several feet upward by the pressure of the 

 gradually accumulated gas. The predisposition of the metal 

 to acquire a dark surface may be greatly diminished by first 

 removing the black substance with dilute nitric acid (or other- 

 wise) and then agitating the liquid gallium in four or more 

 changes of boiling water. The metal thus cleansed partially 

 crystallizes (sometimes with edges more than l cm long) when 

 converted into the solid phase and only shows a slight gray 

 hue after a month's exposure to ordinary air. Since it was not 

 the object of this investigation to identify the black, brown, 

 and white compounds mentioned above we are not prepared at 

 present to give a complete explanation of the reactions 

 involved ; nevertheless, it seems probable that the colored 

 compounds correspond to different degrees of oxidation and 

 that sodium and water play important parts in the observed 

 phenomena. 



During the process of electrolyzing (at room temperature) 

 the alkaline solution of gallium a white, flocculent substance 

 often appears in the liquid, especially in the immediate vicinity 

 of the surface of the anode facing the cathode. When the 

 electrolyte used is the liquid first decanted the white material 

 sometimes forms in relatively large quantities on the anode 

 from which it eventually peels off aud forms a talus at the 

 bottom of the dish. A sample of this substance was collected, 



