1 94- Notices of the Labours of Continental Chemists. 



of isatin are too little examined to enable us to make any abs- 

 tract. Chlorine does not appear to exert any action on chlo- 

 ride and bichloride of isatin, when they are suspended in 

 water, or even under the influence of sunlight. If, however, 

 they are dissolved in alcohol, and chlorine is passed through 

 the solution, they are soon decomposed. A thick fluid is 

 formed. When no more of this is produced, the operation 

 is finished. Sal-ammoniac is also formed in large quantity. 

 In the thick oily fluid is suspended a small quantity of shining 

 lamellae, which may be separated by dissolving the oily fluid 

 in alcohol, after the whole has been freed from sal-ammoniac 

 by means of water. This crystalline substance has received 

 the name of chloride of anil. The alcoholic solution contains 

 hydrochloric aether; by distillation a resinous mass remains 

 in the retort; it still contains chloride of anil, from which it 

 may be separated by solution in alcohol ; if its solution be 

 then distilled, and heated still further, a volatile product is 

 formed, which sublimes in needles. This is called chloruretted 

 chloride of indopten (gechlortes chlorindopten). This sub- 

 stance, when treated with potassa, forms a new acid, chloru- 

 retted chlorindoptenic acid (hyperchlorindoptenic acid?). It 

 lias great similarity to the chlorindoptenic acid, but its for- 

 mula is C 12 CI 10 . 



Chloride of anil may be sublimed if carefully heated ; in- 

 soluble in water, almost so in cold alcohol ; soluble in hot alco- 

 hol. It is not changed by nitric, sulphuric and hydrochloric 

 acids. Formula C 6 CI 4 O 2 . It dissolves in solution of potassa 

 with a purple-red colour ; on cooling brownish purple-red 

 crystals are formed, which contain chloranilic acid. The in- 

 soluble red silver salt is C 6 CI 2 O 3 -f Ag O. The potassa 

 salt is C 6 ' CI 2 O 3 , K O + H 2 O. It explodes on heating. The 

 metallic salts are insoluble. On adding hydrochloric or sul- 

 phuric acid in excess to the warm solution of chloranilate of 

 potassa, reddish grains, or sometimes yellowish-red lamellae 

 of chloranilic acid are precipitated. Dried at 125° it con- 

 tains one atom of water, the crystals contain two atoms. — 

 (Conclusion in our next.) — (Journal fur Praktische Chemie, 

 xxii. p. 257-299.) 



OnCatcchin (Catechinic Acid) and Pyrocatechin {Pyrocatechinic 



Acid). 



Wackenroder has examined the properties of catechin, 

 Zwenger the properties and the chemical composition, and 

 Hagen the constitution alone. The formulae obtained agree 

 neither with one another, nor with those formerly obtained by 

 Svanberg, we need only therefore give those proposed. 



