DETECTION OF ACIDS. 135 



chloride, then calcic chloride, agitate the mixture 



vigorously, and let it stand 10-20 minutes. 



a. No precipitate is formed. - - - - 21 



h. A white precipitate is formed ; filter, and mark 

 the filtrate F. 20. Digest the precipitate in the 

 cold, with sodic hydrate, with frequent agitation, 

 dilute, filter, and boil the filtrate. A white gelat- 

 inous precipitate is formed ; test it with ammonia 

 and argentic nitrate (§ 71). Taetaeic. - - 21 



21. To F. 20, or to the clear mixture of original solu- 

 tion and calcic chloride obtained in 20, add consid- 

 erable alcohol. 



a. 1^0 precipitate. Finis. - - - - B. 

 h. A white precipitate is formed ; filter, wash the 

 precipitate with a little alcohol, dissolve it in a 

 small quantity of dilute hydrochloric acid, add am- 

 monia in slight excess, and boil the liquid some 

 time. 



aa. No precipitate. 22 



hh. A white precipitate is formed ; filter the liquid 

 while boiling hot, and mark the filtrate F. 21. Dis- 

 solve the precipitate on the filter in a very little 

 dilute hydrochloric acid, add ammonia in slight 

 excess, and boil this mixture. A similar white 

 precipitate is formed again. Citric. - - - 22 



22. F. 21, or the solution obtained in 21 that gave no 

 precipitate on boiling, may contain malic acid. 

 Add considerable alcohol to it. 



a. No precipitate is formed. Finis. - - ^' 

 h. A white precipitate is formed. Probably Malic. 

 To be sure, treat the precipitate with acetic acid, 

 add alcohol, filter the liquid if not clear, add plum- 

 bic acetate to the filtrate, and ammonia until the 

 liquid is neutral, filter out the precipitate, wash it, 



