14 IOWA ACADEMY OF SCIENCES. 



II. Aiuyl alcohol contaiuiug .1 m. g. Fe (SCN)3 per c. c. T=152. 



, Other series of experiments with ethyl alcohol, amyl alcohol and ether, 

 demonstrated that the absorbent power of solutions of ferric sulphocyanate 

 in these menstrua diminishes more rapidly than the concentration. The 

 amyl alcohol was distilled from phosphoric acid to remove traces of organic 

 bases and then thoroughly dried. Hydrolysis of the ferric salt can therefor 

 not occur. 



If electrolytic dissociation occurs, the molecular conductivity of these 

 solutions must increase with diminishing concentration and in proportion to 

 the diminishing light-absorbing power. 



The electrical resistance of the same solutions which had been examined 

 optically was thei'efore determined in a resistance cell of the form described 

 by Arrhenius, byOstwald's method with Kohlrausch-Wheatstone bridge and 

 telephone. The specific resistance of the amyl alcohol employed was about 

 100,000,000 ohms per m. m. cube. 



All the measurements showed that the molecular conductivity of the 

 non-aqueous solutions examined diminished with increasing dilution and 

 in about the same ratio as tie reciprocal of the absorbtion coefficient, 

 whereas the molecular conductivity should be greater at high dilutions than 

 at low if the tapering off of the color of the former is due to electrolytic 

 dissociation. 



I am not prepared to present tinal quantitative results at present because 

 my apparatus is not perfectly adapted to the measurements of such high 

 resistances, but there is no reason to question the qualitative results nor the 

 general character of the numerical data. A cell now in course of construc- 

 tion having a much smaller I'esistance constant than that heretofore in 

 use is expected to furnish results of the desired accuracy. 



