CONDUCTIVITY OF ROSANILINE HYDROCHLORIDE. — DAVIS. 41 



These laws having been derived from measurements of the 

 conductivity of certain salts of the aliphatic series, the present 

 work was undertaken in order to extend investigation to solutes 

 containing the benzene nucleus. 



The solute chosen was fuchsine. The solvents used were 

 water, methyl alcohol, ethyl alcohol, and acetic acid. 



Some Properties of Fuchsine. Fuchsine C2oH_„jN3Cl is the 

 hyidrochloric acid salt of rosaniline (triamido di-phenyl 

 tolyl carbinol). It crystallizes in very small rhombic plates 

 which are sparingly soluble in water and dissolve readly in 

 ethyl alcohol.^ 



Like all the salts of rosaniline it is very hygroscopic, a 

 fact W'hich must be remembered in quantitative work.- 



It is a powerful dye and colours the hands and dishes 

 strongly red. From these, however, it is easily removed by 

 dipping in a weak solution of sodium nitrite which has been 

 slightly acidified. The . dye is thus diazotized and may be 

 removed by washing. 



ISTo data can be found about the melting point in 

 Beilstein, in Thorpe's or Carnelley's tables or in any standard 

 w^ork of reference. The melting point was, therefore, deter- 

 mined as described in this paper and found to be 216. 8°C. 



The dye was also found to be readily soluble in methyl 

 alcohol and acetic acid and fairly soluble in acetyl chloride 

 and acetone. It is insoluble in acetic ester. . 



Purification of Fuchsine. Merck's C. P. fuchsine was 

 recrystalized three times fro;m water. A sample from each 

 was dried at 120 and a solution made, (in order to obtain com- 

 l^lete solution of the salt, in this and all subsequent measure- 

 ments, it was found necessary to warm the solution). It was 

 found that the conductivity decreased about ten per cent, for 

 the first recrystallization, three for the second, and that the 

 change for the third was inappreciable. 



1. Allen, A. H. : " Commercial Organic Analysis," Vol. 3, Part I, p. 276. 



2. Hoffman : Proc. Roy. Soc. 12 2, (1862). 



