1871.] Bromine-substitution Compounds of the Orchis. 75 



the liberated iodine had been reconverted into hydriodic acid. "When all 

 the pentachlororcin had been introduced, the digestion was continued until 

 the trichlororcin appeared as a colourless oily layer at the bottom of the 

 flask. On cooling, a considerable portion more crystallized out of the 

 hydriodic acid in colourless needles. The oily trichlororcin, which solidified 

 on cooling, was dissolved in a small quantity of spirit, filtered to separate 

 it from the excess of amorphous phosphorus, and the alcoholic solution 

 precipitated by water. The amount of crude product thus obtained was 

 about 75 per cent, of the weight of the pentachlororcin originally employed. 

 One or two crystallizations from boiling water slightly acidified with acetic 

 acid rendered it quite pure. If very pure pentachlororcin had not been 

 employed in the preparation the crude product was more or less coloured, 

 and could only be purified with considerable difficulty, as the colouring- 

 matter adheres to the trichlororcin with great obstinacy. It was found, 

 however, that several alternate crystallizations from benzol and petroleum- 

 oil, and a final crystallization from water, almost entirely removed the 

 brown colouring- matter. It fuses to an oil under boiling water, in which 

 it is moderately soluble, crystallizing out almost completely on cooling in 

 long colourless transparent needles, which become white and opaque when 

 exposed to the air. It is but sparingly soluble in carbon disulphide, mo- 

 derately in petroleum-oil, rather more so in benzol, and excessively soluble 

 in ether and alcohol. It is soluble in boiling glacial acetic acid, and 

 crystallizes out on cooling in thin transparent plates, which become white 

 and opaque on the addition of water. Trichlororcin melts at 123°, and 

 when heated to a very much higher temperature it blackens and gives off 

 hydrochloric acid, even under diminished pressure. It cannot, therefore, 

 be distilled in vacuo, but it passes over readily with the vapour of water. 

 "When heated for several hours to 180° with moderately strong hydriodic 

 acid and phosphorus, it was found to be reconverted into orcin, which could 

 be extracted from the solution by agitating it with ether. The addition of 

 alcoholic ammonia to a solution of the trichlororcin in alcohol threw down 

 a white crystalline precipitate, but slightly soluble in water or alcohol. 

 This compound, when dissolved in a large excess of dilute aqueous ammonia, 

 and submitted to the action of metallic zinc in a close vessel at the ordinary 

 temperature, yielded a colourless solution. On exposing this to the air, 

 however, it acquired a fine blue colour, which was changed to red by the 

 action of acids. Further investigation will no doubt show the nature of 

 this compound. 



Analysis of Trichlororcin. 



I. "257 grm. substance gave *486 grm. argentic chloride. 



II. *302 grm. substance gave *572 grm. argentic chloride. 



III. '2i6 grm. substance gave '293 grm. carbonic anhvdride and 

 *04f3 grm. water. 



