Electromotive Properties of Electrical Organ of Malapterurus. 37 



The latter line is seen only in the absence of manganese, as it very 

 nearly coincides with one of the group of strong manganese lines ; it 

 is, therefore, obscured in the spectra of the Bessemer flame and of 

 the crude iron. ^ 



The oxide of gallium was separated as far as possible from all other 

 substances and heated in the oxy-hydrogen flame and the character- 

 istic spectrum was then photographed from this oxide. 



3. Evidence from the Roasted Ore, and substances separated therefrom. 



The roasted Cleveland ore was heated alone for thirty-five minutes 

 in the oxy-hydrogen flame, it gave only a very faint indication of one 

 line in the spectrum of gallium. The solution extracted from the 

 ore by digesting it with warm dilute hydrochloric acid of double 

 normal strength, when boiled with ammonium acetate gave a precipi- 

 tate, the spectrum of which contained the line 4171'6 fairly strong. 



The silicious residue insoluble in strong hydrochloric acid, when 

 decomposed by fusion with caustic potash and subsequent boiling 

 with water, after concentration of the solution so as to retain the 

 gallium, gave a spectrum containing both lines, 4171/6 and 40327. 

 All other elements had been removed. 



The wave-lengths given are on Rowland's scale. The lines were 

 measured on many plates and also repeatedly on the same plate, the 

 results being the same in each case. 



Electromotive Properties of the Electrical Organ of 

 Malapterurus electricm" By FRANCIS GOTCH, M.A. (Oxon.), 

 F.R.S., and G. J. BuRCH, M.A. (Oxon.). Received April 

 2, Read May 7, 1896. 



(Abstract.) 



The experiments were made upon six specimens of Malapterurus 

 electricus, 12 to 15 cm. in length, brought from the River Senegal by 

 Mr. A. Ridyard (ss. "Niger"), and generously placed at the. dis- 

 posal of the authors by the Liverpool Corporation Museum Committee, 

 to whom and to Dr. Forbes, the Director of the Museum, the authors 

 desire to express their thanks. 



Three of the specimens were killed, in order to carry out experi- 

 ments upon the isolated organ. The instrumental methods employed 

 by the authors for determining for the first time the characters and 

 time relations of the activity of the organ response were chiefly the 

 following : 



(a.) The record of the frog nerve muscle galvanoscope. 

 (&.) The galvanometer connected with a suitable .rheotome. 



