134 SPECIAL METHODS OF ANALYSIS. 



01* iodine or ferrocyanogen has been found. - - 16 



10. a. The precipitate in 12 was white, and no cyano- 

 gen, iodine, or ferrocyanogen, has been found. 



Chlorine. 17 



5. Not Avhite, or one or more of these substances 

 was found ; treafrthe precipitate obtained in 15, or, 

 if cyanogen was absent, that obtained in 12, with 

 amnionic hydrate, filter, and add dilute nitric acid 

 to the filtrate until acid reaction. A white pre- 

 cipitate appears, which, if abundant, collects in 

 curdy flakes on agitating the mixture. Chloeine. 17 



17. Treat a portion of the original substance with a 

 little dilute sulphuric acid if it is a solid, or with 

 concentrated acid if it is a solution, add copper 

 turnings, and heat the mixture. Red fumes are 

 evolved, which may be more readily perceived on 

 holding the tube over white paper, and looking 

 through it lengthwise. Nitric. - - - 18 



18. a. A portion of the solid substance, when quickly 

 heated to a high temperature on platinum foil, is 

 blackened, with separation of carbon, and an odor 



of burning organic matter is given off. - - 19 



h. Not blackened. Absence of acetic, tartaric, 

 and other organic acids. Finis. - - - - B. 



19. A portion of the solid or solution gives acetic 

 ether when heated with concentrated sulphuric 

 acid and alcohol ; the pleasant aromatic odor of 

 this ether may be most readily distinguished from 

 that of common ether, which is formed at the 

 same time, after the liquid has become quite cold. 

 Acetic. - - 20 



20. To a portion of the first solution, that must be tol- 

 erably concentrated, add ammonia until it is faint- 

 ly alkaline, filter if not clear, add a little amnionic 



