438 



SCIENCE 



[N. S. Vol. XL VII. No. 1218 



death will be deplored by all systematic botan- 

 ists, as well as by all who knew his genial 

 personality." 



Dr. Ferdinand Braun, of Germany, who 

 shared the ISTobel Prize in 1905 with Guglielmo 

 Marconi, for distinguished achievements in the 

 invention of improved methods of wireless 

 telegraphy, died on April 14 at a Brooklyn 

 hospital. Death was caused by a heart attack 

 induced by an overdose of morphine, which Dr. 

 Braun is alleged to have taken before arriving 

 at the hospital, to ease pain from an intestinal 

 disorder from which he had been suffering for 

 three years. Dr. Braun was born in Fulda, 

 Germany, in 1850. He came to this country 

 in 1914 as a witness in litigation between the 

 Marconi Wireless Company and the German 

 company which built and operated the wireless 

 station at Sayville, L. I. 



Mr. H. J. HJELM, formerly deputy-principal 

 chemist of the British Government Laboratory, 

 has died at the age of seventy-nine years. 



UNIVERSITY AND EDUCATIONAL 

 NEWS 



Me. J. C. Lincoln has presented to Oberlin 

 College the Mary McKenzie Lincoln Scholar- 

 ship Fund, to be used in paying the term bill 

 of some young woman, a student in Oberlin, 

 who desires to continue her studies at the sum- 

 mer school of the Marine Biological Labora- 

 tory at Woods Hole. 



Through the will of the late Henry Jane- 

 way Hardenbergh, of New York, Eutgers Col- 

 lege has received Mr. Hardenbergh's library in 

 architecture and the smn of $20,000. Mr. 

 Hardenbergh designed and erected Geological 

 Hall and the Kirkpatrick Chapel, and two 

 years ago carried out the remodelling of the 

 chapel. 



Announcement has been made that Presi- 

 dent Wilson has directed the War Department 

 to establish an infantry unit, senior division, 

 of the B«serve Officers' Training Corps at 

 Columbia University. 



At the University of BufPalo medical school. 

 Dr. Edward W. Koch has been appointed pro- 

 fessor of pharmacology and Dr. Wayne J. At- 



well, professor of anatomy, both on a full-time 

 teaching and research basis. 



Miss Phyllis M. Borthwick, lecturer in 

 physics at the Ladies' College, Cheltenham, has 

 been appointed assistant-professor of physics 

 and chemistry at the Lady Hardinge Medical 

 College for Women, Delhi. 



DISCUSSION AND CORRESPONDENCE 



NOTE ON A REVERSE CONCENTRATION CELL 



In the ISTemst theory of the concentration 

 cell the solution tension of both electrodes is 

 assiuned to be the same, but the electrode in 

 the more concentrated part of the electrolyte is 

 supposed to have its rate of solution retarded 

 by the back " osmotic pressure " of its own 

 ions. 



Another possible way of regarding the phe- 

 nomenon is to suppose that the electrode in the 

 solution of higher specific inductive capacity 

 always goes into solution faster than the other, 

 and hence becomes the anode. From this 

 point of view, the solution of metallic salts 

 in water lowers the specific inductive capacity 

 of the water, and hence the electrode in the 

 more concentrated solution of the concentra- 

 tion cell becomes the cathode. 



A concentration cell for demonstration pur- 

 poses is often made by pouring water care- 

 fully upon a concentrated solution of stannous 

 chloride, so that the two liquids do not mix, 

 and placing a rod of tin in the two solutions. 

 The tin will rapidly dissolve in the dilute solu- 

 tion at the top, and crystals of tin will be 

 deposited from the concentrated solution at 

 the bottom. 



If, instead of pouring water upon the con- 

 centrated solution, a solution of stannous 

 chloride in ether be poured upon it and the 

 two solutions be shaken together, most of the 

 salt in solution will go into the water and only 

 a little will remain in the ether and water at 

 the top. Thus the tin ions are highly concen- 

 trated in the water and are very dilute in the 

 ether, and their " osmotic pressure " is corre- 

 spondingly greater in the water than in the 

 ether. Notwithstanding this difference of con- 

 centration, if the tin rod be placed in the 

 two solutions, ions wiU dissolve off it in the 



