76 



Dr. J. Stenhouse on Chlorine- and 



[Dec. 21, 



Theory. 



C- = 84 =36-93 

 H 5 = 5 = 2-20 

 Cl 3 =106-o = 46-81 

 2 = 32 =14-06 



227-5 100-00 



L II. 

 46-78 46-86 



III. Mean. 

 37-00 37-00 

 2-37 2-37 

 46-82 



I. was from the pentachlororcin prepared by the action of chlorine hy- 

 drate on orcin ; II. and III. from that prepared by hydrochloric acid 

 and potassium chlorate. The substance was dried in vacuo. 



This trichlororcin differs considerably in its melting-point and other pro- 

 perties from that described by De Luynes * as formed by the action of 

 hydrochloric acid and potassium chlorate on orcin. Moreover, although 

 many attempts were made to prepare trichlororcin by his method with 

 varying proportions of the materials, pentachlororcin was invariably ob- 

 tained, contaminated, however, in some instances, with a large amount of 

 viscid oily impurities. I conclude, therefore, that De Luynes's tri- 

 chlororcin was either isomeric with that above described, or that it was an 

 impure substance. 



Bromorcin. 



Pe?itabro?norcin, C 7 H 3 Br.0 2 . — This compound was readily formed by 

 the action of an excess of bromine on orcin. Seven parts of bromine and 

 about 200 of water were placed in a stoppered bottle, and a moderately 

 strong aqueous solution of one part of orcin added by small portions, with 

 constant agitation. The yellow crystalline product thus obtained, amount- 

 ing to 370 per cent, of the weight of the orcin, was then collected, and 

 purified by repeated crystallization from carbon disulphide, in a manner 

 similar to the corresponding chlorine compound. It is almost insoluble in 

 water, very soluble in alcohol and ether, and moderately so in benzol and 

 carbon disulphide, from the latter of which it may be obtained in very large 

 and almost colourless transparent crystals. It melts at 126°, and when 

 boiled with water appears to undergo a decomposition similar to the penta- 

 chlororcin. Heated with concentrated sulphuric acid it gradually dissolves, 

 and on continuing the heat hydrobromic acid and bromine are evolved in 

 abundance. Like the corresponding chlorine compound, it dissolves in hot 

 nitric acid, crystallizing out again on cooling, but is at the same time far 

 more readily decomposed. When boiled with amorphous phosphorus and 

 moderately strong hydriodic acid it is rapidly decomposed, and passes 

 into solution probably as orcin. With very weak hydriodic acid, however, 

 containing about one per cent, of iodine and excess of amorphous phos- 

 phorus, the decomposition takes place more gradually, and a heavy oily 

 layer is obtained, which solidifies on cooling. This, after purification, was 



* Ann. Chern. Pharrn. vol. cxxx. p. 34 ; Kekule's ' Benzolderivate,' vol. i. p. 388. 



