Apeil 28, 1922] 



SCIENCE 



461 



precautions, they can not be constructed for 

 smaller amounts of solution. This can be accom- 

 plished, not by a smaller model of the same 

 shape, but by making the bottom of the elec- 

 trode vessel more conical in shape and taking 

 particular precautions in sealing the electrode 

 as near the base of the vessel as is conve- 

 niently possible. It is not desirable to materially 

 decrease the diameter of the upper portion of 

 the electrode vessel, because in so doing, the 

 bubbling process is seriously interfered with. 



CONSTRUCTION AND OPEEATION 



The electrode vessel E was made by sealing 

 a short piece of glass tubing to an ordinary 

 three inch soda-lime tube. The glass tulje was 

 then bent into position to make the side arm, A. 

 The electrode proper, which consists of a piece 

 of platinum foil, was sealed as near the base 

 of the main vessel as possible. The protruding 

 end of the foil was bent into a loop and par- 

 tially embedded in sealing wax to give added 

 mechanical strength. The rubber stopper, D, 

 is used to prevent the rapid diffusion of air 

 into the electrode vessel. The support, S, 

 shown in the diagram by means of dotted lines, 

 was made from a No. 12, two-holed rubber 

 stopper by cutting out the portion between 

 the holes. 



After platinization of the electrode, about 

 1.5 c.e. of the solution to be tested are put 



into the electrode vessel, E. Purified hydrogen 

 is bubbled through the solution by way of the 

 side arm, A. Usually, about three minutes of 

 bubbling are required for saturation. 



The diagram shows the electrode in position 

 for a measurement. C represents the side arm 

 of the calomel electrode, V, a vessel containing 

 a saturated KCl solution, and B, a tube tilled 

 with saturated KCl and plugged at the smaller 

 end with fUter paper to prevent the too rapid 

 siphoning of KCl from V. 



When properly constructed, this electrode 

 possesses the following features, which should 

 make it applicable for quite general use : 



1. Simplicity of construction. 



2. Ease of operation. 



3. Requires only a very small amount of 

 solution for a determination. 



J. Rot Haag 



Pennsylvania State College 



THE OKLAHOMA ACADEMY OF 

 SCIENCE 



The tenth annual meeting was held in Okla- 

 homa City, on February 10, and at the University 

 of Oklahoma, Norman, on February 11, 1922. 

 The following papers were read: 



February 10 



Presidential address: The possibility of the re- 

 demption of the Great Plains from its semi-arid 

 condition; J. B. Thobuen. 



Some notes on the Bois Fort Chippewa of Minne- 

 sota: Albert B. Eeagan. 



Identification of Anthoceros in the Oklahoma 

 cryptogamio flora: M. M. Wickham. 



Notes on the migration of Macrochelys lacertine: 

 M. M. Wickham. 



Further notes on migration of Terrapene Carolina 

 in OMahoma: M. M. Wickham. 



Identification of fresh water sponges in the Okla- 

 homa fauna: M. M. Wickham. 



Bed and white blood corpuscles and catalase in 

 the blood of non-complement guinea pigs: 

 L. B. Nice, A. J. Neill and H. D. Moore. 



The regular tetrahedron in relation to its cube 

 and other solids: Oscar Ingold. 



Oklahoma geography in the high schools: C. J. 

 Bollinger. 



Tlte poisonous substance in cotton seed: Paul 

 Menaul. 



The chemistry of the pecan: W. G. Feiedemann. 



