IOWA ACADEMY OF SCIENCES. 15 



Ivau lvlobukofT(Zeit. Phys. Chem. IV, 429,) has observed that solutions of 

 hj'drochloric acid in ether and iu arayl alcoliol exhibit a diminution of 

 molecular conductivity with increasing dilution of the solutions and has 

 shown that it is not due to any chemical action of the acid upon the alcohol. 

 This phenomenon evidently belongs in the same class with that which I have 

 observed iu the case of ferric sulphocyanate solutions. 



Neither of the theories as yet advanced seems capable of explaining all 

 the. facts and more extended studies of the spectroscopic and electrical 

 behavior of other colored salts in non-aqueous solvents must be made before 

 any theory can be advanced with profit. 



ELECTROLYSIS OF SILVER— LABORATORY NOTES. 



■\V. S. HENDRIXSON. 



(Abstract.) 



The author exhibited some pieces of appai'atus devised in connection 

 with his work on the atomic weight of tin, and also a quantity of pure 

 silver prepared by electrolysis of the pure silver of Stas in strong nitric acid 

 solution. The method of electrolysis was essentially that of Abrahall* as 

 modified by Richardsf. By using a strong acid solution containing fifteen 

 per cent of silver and a battery consisting of sixteen gravity cells the silver 

 was obtained iu large crystals and no peroxide was formed at the positive 

 pole. Separate experiments showed that silver deposited under these con- 

 ditions, from a solution to which copper had been added, contained no trace 

 of the latter metal. 



The apparatus exhibited included: 



1. A platinum condenser for the preparation in pure condition of such 

 substances as attack glass or metals other than platinum, viz, water, hydro- 

 chloric, hydrobi-omic and nitric acids. Cork or other connections are 

 avoided by selecting a retort into the neck of which the condenser tube tits 

 closely. The first portion of the vapor condenses between the glass and 

 platinum and forms a seal. The condenser tube is bent so that the neck of 

 the retort or flask may be inclined upward to secure a back flow and to 

 avoid the mechanical carrying over of substances by the spray. 



2. A separatory funnel having a doubly-bored stop-cock like that in the 

 well-known Lunge's nitrometer. On turning the cock to arrest the flow of 

 the liquid the column in the stem, which in the ordinai'y funnel remains in 

 the stem, being held by atmospheric pressure, falls at once since it is 

 replaced by air which enters the stem through the second hole in the stop- 

 cock. 



•Journal Cliem. Soc, 1892, p. 660. 



tProc. Amer. Academy, Vol. XXVIII, p. 22. 



