84 MAPLE-SAP SIRUP. 



ammonium chloric! solution (Bulletin 107, Revised, p. 11), and 

 finally with 80 per cent alcohol until all chlorids are removed, as 

 indicated by testing the filtrate with silver nitrate. Dissolve the 

 remaining yellow precipitate in hot water and wash into a platinum 

 dish, evaporate, and after drying at 100 C. weigh as potassium 

 platinic chlorid. 



Lime and phosphoric acid. Pour the remaining portion (50 cc) 

 into a platinum dish and evaporate to dryness. Add a few drops of 

 concentrated nitric acid to oxidize any phosphates present and drive 

 off the excess of nitric acid by heating over a burner flame. Treat 

 the dry residue with a few drops of nitric acid, then transfer to a 

 beaker with about 50 cc of water and bring to a boil, adding a 

 few cubic centimeters of ferric chlorid solution to combine with all 

 of the phosphates. Then add 2 grams of dry ammonium acetate and 

 boil the solution for two minutes. Use the filtrate for the lime 

 determination. (In some cases the precipitate on the filter paper 

 was dissolved in hydrochloric acid, reprecipitated with ammonium 

 hydroxid, and this filtrate added to the filtrate for the lime deter- 

 mination. This extra treatment was found to be unnecessary, 

 however, as no lime was found in the second filtrate.) 



Dissolve the residue on the filter paper in nitric acid, neutralize 

 with ammonium hydroxid, add 10 grams of ammonium nitrate, and 

 precipitate the phosphates with molybdate solution (Bulletin 107, 

 Revised, p. 2). Allow this precipitate to stand overnight in the cold, 

 filter, wash with cold water, and add standard potassium hydroxid 

 solution to dissolve it. Then titrate this solution with standard 

 hydrochloric acid and determine the amount of phosphoric acid 

 (P 2 O 6 ). (See also Bulletin 107, Revised,.p. 4.) 



Boil down the filtrate for lime to a small volume and add ammo- 

 nium hydroxid and ammonium oxalate. Weigh the precipitated 

 calcium oxalate as calcium oxid. 



Calculate all determinations to per cents of the sirup and finally 

 to per cents of the total ash. 



ANALYTICAL RESULTS. 



The results of this work are given in the following table where they 

 are grouped and arranged by States. The samples are designated 

 by the laboratory number, so that the data given in other tables on 

 the same samples may be compared if desired. 



