DISCUSSION OF CHEMICAL DATA. 



83 



maple ash, is found and more if baking soda has been used as a 

 cleanser. Sulphate and phosphates, the latter in particular, are also 

 normal constituents of maple ash, some samples having a compara- 

 tively large per cent, while chlorin may or may not be normally 

 present. 



Schroeder a has made some analyses of the ash of maple sap, 

 which are given in the following table. The figures expressed as 

 ratios have been calculated by the author for comparison with those 

 given on page 85 on the finished maple sirup. 



Composition of the ash of maple sap (Schroeder). 

 (Expressed as parts in 100 cc of sap.) 



The ash of 100 samples, selected so that all States were represented, 

 was analyzed, lime, potash, phosphoric acid, and sulphates being 

 determined. The following methods of analysis were used: 



METHODS OF ANALYSIS. 



Ash 40 grams of the maple sirup in the usual way in a large platinum 

 dish over a low flame and finally in a muffle. Treat the resulting 

 ash with dilute hydrochloric acid and heat. If much remains undis- 

 solved, filter the solution and reignite the residue. Treat this 

 residue again with dilute hydrochloric acid and heat. Combine the 

 two filtrates and make up to a volume of 100 cc. Use aliquot por- 

 tions for the individual determination as outlined. 



Sulphates. Make up a 25 cc portion to about 100 cc with water, add 

 a few drops of hydrochloric acid and heat to boiling. While hot 

 stir in a 10 per cent barium chlorid solution, allow to stand over- 

 night and determine the sulphates as SO 3 by weighing the barium 

 sulphate. 



Potash. Place a 25 cc portion in a porcelain dish and add 

 platinum chlorid solution in excess. Evaporate the resulting liquid 

 on a steam bath to a sirupy consistency. Wash the whole on to a 

 filter paper with 80 per cent alcohol and wash out the excess of 

 platinic chlorid with this reagent. Then wash the precipitate with 



Land. Vers.-Stationen, 1871, 14: 136. 



