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Dr. E. Schunck. 



becomes nearly colourless, and deposits rosettes of lustrous crystalline 

 needles, presumably of unchanged substance ; so that it appears no 

 sulphonic acid is formed in this reaction, the colour of the solution in 

 sulphuric acid being due probably to a loose combination of the sub- 

 stance with the acid. The substance is soluble in boiling aniline ; the 

 solution is dull red, and gives with alcohol a deposit of brilliant 

 needle-shaped crystals, the filtrate from which shows the same 

 spectrum as the solution in acetic acid. The substance is insoluble 

 in aqueous caustic potash, but dissolves in alcoholic potash, giving a 

 yellow solution. 



a B C 



Absorption Spectra of Scatocyanin Solutions. 



1. Scatocyanin in glacial acetic acid. 



2. The same in concentrated sulphuric acid.* 



There is another substance of definite character and assuming a 

 crystalline form which I have obtained, though not always, along with 

 the preceding. Having treated the faeces of a cow that had lived for 

 some time on green vegetable food, with acidulated alcohol (seventeen 

 parts of rectified spirit to three of sulphuric acid, the mixture pre- 

 scribed for the preparation of so-called stercobilin), I added water to 

 the filtered extract and shook up with chloroform. The chloroformic 

 liquid after separation was evaporated, when it left a brown syrup. 

 This, treated with boiling alcohol, dissolved in part, a semi-crystalline 

 pink residue being left undissolved, which, after separation, was found 

 to be soluble in boiling acetic acid with a crimson colour, and consisted 

 doubtless of Scatocyanin. A further quantity of this was deposited 

 on again evaporating ; on further evaporation, the filtrate left a thin 

 brown syrup which was mixed with a large quantity of alcohol. On 

 standing, a voluminous crystalline deposit separated, which was filtered 

 off and slightly washed with alcohol. 



The following are the chief properties of the substance so pre- 

 pared : When dry it has the appearance of a dull red mass of crystal- 

 line needles. Heated on platinum, it melts easily to a brown mass, 

 solidifying again on cooling ; on further heating, it gives off red fumes 



* These spectra were mapped by my son, Charles A. Schunck. 



