192 Notices of the Labours of Continental Chemists. 



It may be prepared in another way. The crystalline mass 

 obtained by acting on indigo-blue with potassa is dissolved in 

 alcohol, and allowed to stand exposed to the air until its 

 greenish colour has passed into brown. A stream of carbonic 

 acid is then passed through the solution in order to saturate 

 the free alkali, and the alcohol is distilled off after the car- 

 bonate of potassa has been separated. On concentration, an- 

 thranilate of potassa crystallizes out in thin lamellae, the mother 

 liquor is separated by bibulous paper, the salt dissolved in as 

 small a quantity of water as possible, and acetic acid added, 

 which produces a crystalline precipitate of hydrated anthra- 

 nilic acid. Anthranilic acid is, when pure, perfectly colour- 

 less, has a sweet taste even when in combination with alkali. 

 If the decomposition of the potassa salt be conducted very 

 slowly it may be obtained in scaly crystals, like benzoic acid. 

 It is difficultly soluble in cold water, easier in boiling water. 

 In alcohol and aether it is easily soluble. It melts at 135°, 

 and sublimes; at a higher temperature it is decomposed. The 

 alkaline salts are soluble, the copper, zinc and lead salts are 

 crystalline powders. The formula of the hydrated acid is 



C 14 H 12 N 2 Q3 + H 2 0j that of the silver saU C 14 H 12 N 2 Q3 



+ Ag O. Hydrated anthranilic acid heated above its point 

 of fusion is decomposed into carbonic acid and anilin, C 14 H 12 

 N 2 O 3 + H 2 O = C 12 H 14 N 2 + 2 C O 2 . In an experiment 

 it was found that the carbonic acid was 31*49 per cent, of the 

 employed acid; according to calculation it should be 3T93. 

 By distilling an anthranilate anilin is also obtained, but the 

 decomposition is much more complicated ; carbon is separated. 

 It has been already stated that by the action of dilute sul- 

 phuric acid on chrysanilic acid a substance is obtained which 

 crystallizes as the fluid cools; it is bluish biack, soluble in 

 alcohol, with a purple-red colour. After drying it loses this 

 solubility; it is easily decomposed by alkalies; indigo-blue is 

 formed, &c. {Journal fur Praktische C/iemie, B. 23, p. 67.) 



On the Products of the Decomposition of Chloride and 

 Bichloride of Isatin. 



Erdmann has continued his experiments on these highly 

 interesting bodies, and in the following memoir the products 

 of decomposition are examined. When a stream of sulphu- 

 retted hydrogen is passed through a solution of chloride or 

 bichloride of isatin, or the analogous bromides, the solution 

 becomes colourless, and a white sediment is formed, consist- 

 ing of sulphur and a new body, which may be freed from the 

 sulphur by digestion with bisulphuret of carbon. A better 

 method is to dissolve the chlorides in hydrosulphuret of am- 



