396 Dr. Hofmann on the Metamorphoses of Indigo. 



guishes the chlorinated base are found in nearly all its com- 

 pounds with acids ; most of them are precipitated as a crystal- 

 line mass by mixing its alcoholic solution with the respective 

 acids. By recrystallization from boiling water or alcohol they 

 are obtained quite pure ; with the exception of the platinum 

 and palladium double salts they are white, but the larger 

 crystals have generally a shade of yellow. An excess of acid 

 imparts to them a violet tint. An elevation of temperature 

 is observed in the formation of these compounds, &c. ; they 

 possess the true character of salts by their capability of under- 

 going double decomposition. As this base has no alkaline 

 reaction, all its salts, as a consequence, possess acid properties. 

 A large excess of the base can be heated to fusion under di- 

 lute hydrochloric acid without removing the acid properties 

 of the supernatant fluid. 



The salts are decomposed with the greatest ease by the 

 caustic and carbonated alkalies; in the latter case with evolu- 

 tion of the carbonic acid, which does not unite with the base. 

 The base itself separates in the form of a crystalline mass. 

 The same decomposition is also produced by hydrochlorate 

 of ammonia in solution. By heating it, however, in a tube 

 with hydrochlorate of ammonia, evolution of ammonia takes 

 place, and the hydrochlorate of the base is deposited on the 

 cool portion of the tube. 



Its capacity of saturation is the same as that of aniline, 

 although the atom of the latter is lower than that of the former 

 by the difference of the equivalents of chlorine and hydrogen 

 (442-65 — 12-50 = 430-15). 



The constitution of the salts in no respect differs from those 

 of ammonia. They unite directly with the hydracids, and 

 with the oxacids by the addition of an equivalent of water. 



Sulphate of Chloranilhie.—SO^, Ci^i^fl^-\-UO. 



The alcoholic solution of chloraniline forms, by the addi- 

 tion of a few drops of sulphuric acid, a white crystalline mass, 

 which by re-solution in boiling water separates on cooling as a 

 confused mass of tabular crystals. From boiling alcohol, in 

 which the salt is less soluble, it crystallizes in stellated tufts 

 of fine silvery needles. Their crystalline form cannot how- 

 ever be determined. Even by slow evaporation of the alco- 

 holic, as well as the watery solution, over sulphuric acid, I 

 was unable to obtain large crystals. The salt is not volatile. 

 By heating, a portion of the base escapes unchanged, while 

 the remainder becomes black and evolves sulphurous acid. 



Only one combustion of this salt was made. 0-3445 grm. 



