400 Dr. Hofmann on the Metamorphoses of Indigo. 



tion of the bichloride of platinum by the presence of water. 

 Evaporated over sulphuric acid this salt forms little rounded 

 lumps, which exhibit no facets. On burning with chromate 

 of lead the following result was obtained : — 



0*463 grm. of the platinum double salt gave 0*374 grm. of 

 carbonic acid and 0*096 grm. of water; corresponding in the 

 100 parts to Carbon . . . 22*03 



Hydrogen . . 2*30 



These numbers, with the determination of the platinum 

 already mentioned, give the following formula : — 



cm, Ci^l^AN + ci^Pt. 



Theory. Experiment. 



I eq. of the double salt = 4 168*65 



Bichloride of Mercwy and Chloraniline. 

 This salt can be obtained in beautiful fine needles by pour- 

 ing an alcoholic solution of the base into a hot solution of 

 corrosive sublimate. At first the fluid remains clear, but 

 after a ^ew moments begins to get turbid, and gradually 

 thickens completely into a mass of needle-form crystals of the 

 double salt. I have not investigated other salts of the base. 

 I may, however, mention a very beautiful double salt formed 

 with chloride of zinc: by the mixture of the two solutions the 

 fluid remains at first clear, but after a short time becomes a 

 mass of silvery crystals. 



d. Products of the Decomposition of Chloraniline. 



I have not as yet so fully studied the products of the de- 

 composition of this base as they deserve. Indeed it appears 

 to suffer in contact with other bodies the same changes as 

 aniline. The presence of the chlorine seems to have no influ- 

 ence in the processes of transformation, but passes over into 

 the new products just as the hydrogen of aniline which it has 

 replaced. I intend to investigate this subject more fully, and 

 shall mention here only those phaenomena which came under 

 my observation during the course of the present inquiry. 



Action of the Oxj/genated Compounds of Chlorine on Chloraniline. 

 On adding crystals of this substance to a mixture of chlo- 

 rate of potash and hydrochloric acid, the fluid at first becomes 



