138 SPECIAL METHODS OF ANALYSIS. 



and then add dilute sulphuric acid as long as a pre- 

 cipitate is formed. 



a. No precipitate is formed, even after vigorous 

 agitation and some time ; expel the alcohol from 

 the liquid by boiling it a few minutes, and mark it 



F. 3. 



5. A white precipitate is formed ; let the mixture 

 stand awhile, filter the liquid while hot, boil the 

 filtrate a few minutes to expel the alcohol, and 

 mark it F. 3. - - . - . . 



4. Agitate the precipitate obtained in 3 vigorously 

 with considerable water, filter, and add amnionic 

 oxalate to the clear filtrate. A white precipitate 

 indicates Calcium. - - _ . - 



5. Treat the contents of the filter in 4 with ammonic 

 tartrate, heat gently, filter, acidify the titrate 

 with acetic acid, and add a little potassic dichro- 

 mate. A yellow precipitate indicates Lead. 



6. Wash the residue on the filter in 5 well, boil it 

 about 10 minutes with 8-10 times its bulk of sodic 

 carbonate, add water, filter, wash the contents of 

 the filter very carefully, pour a little dilute hydro- 

 chloric acid over this residue, and add calcic sul- 

 phate to the solution that passes through. A fine 

 white precipitate, or a turbidity, indicates Barium. 



7. Put about a third of F. 3, or a corresponding 

 amount of the first solution, into a small flask, add 

 baric hydrate as long as it gives a precipitate, and 

 then a little more, so as to be sure of an excess, 

 heat the mixture, and hold a piece of nioistened 

 red litmus-paper or yellow turmeric-pnper in the 

 tube. The paper is colored blue or brown. Am- 

 monium. 



8. Heat the mixture in 7 until all or nearly all the 

 ammonia is expelled, filter, add a little baric hy- 



