VI. PER CENT OF SOLUBLE AND INSOLUBLE ASH. 



To the platinum dish containing the ash (from determination V) add 40 cc of hot 

 water and boil gently for two minutes, using care to avoid spattering. Filter through 

 a small ashless filter and wash with hot water until the filtrate amounts to about 100 cc. 

 Retain the filtrate for making determination VII, alkalinity of soluble ash. 



Transfer the filter paper containing the insoluble ash to the same platinum dish 

 and carefully ash at a low red heat, as before. Cool and weigh. The increase in 

 weight over the platinum dish is due to the insoluble ash. Divide this quantity by 

 5 and multiply by 100 and the percentage obtained is the insoluble ash. Subtract 

 this per cent of insoluble ash from the per cent of total ash obtained in determination 

 V and the result is the per cent of soluble ash. To check this figure, the percentage 

 of soluble ash can be obtained direct by evaporating the 100 cc of water to dryness 

 and weighing. Save the platinum dish with the insoluble ash for determination 

 VIII, alkalinity of insoluble ash. 



The following average results have been compiled : 



Pure maple sugar percentage of soluble ash: 



Jones . 0.36 to 0.63; average, 0.48 



Hortvet_ _ 0.33 to 0.67; average, 0.45 



Pure maple sirup percentage of soluble ash: 



Jones _ 0.29 to 0.47; average, 0.38 



Hortvet ... 0.21 to 0.49; average, 0.39 



Bureau of Chemistry 0.25 to 0.63; average, 0.38 



Pure maple sugar percentage of insoluble ash: 



Jones__ _ 0.20 to 0.87; average, 0.43 



Hortvet . 0.32 to 0.78; average, 0.53 



Pure maple sirup percentage of insoluble ash: 



Jones . 0.16 to 0.51; average, 0.22 



Hortvet . 0.15 to 0.55; average, 0.31 



Bureau of Chemistry 0.14 to 0.56; average, 0.22 



VII. ALKALINITY OF SOLUBLE ASH. 



Transfer the 100 cc of water solution from the preceding determination to a beaker 

 or porcelain evaporating dish and determine the alkalinity by titrating with tenth- 

 normal hydrochloric acid, using methyl orange as an indicator. The number of 

 cubic centimeters of acid used divided by 5 gives the number of cubic centimeters 

 of tenth-normal acid necessary to neutralize the ash of 1 gram of sample, which 

 figure is used to express the alkalinity of the soluble ash. 



Pure maple sugar cc of acid necessary to neutralize 1 gram: 



Jones. . " 0.40 to 0.80 ; average, 0.61 



Hortvet 0.55 to 0.95 ; average, 0.66 



Pure maple sirup cc of acid necessary to neutralize 1 gram: 



Jones 0.30 to 0.66; average, 0.51 



Hortvet 0.38 to 0.66; average, 0.52 



Bureau of Chemistry.. 0.26 to 0.68; average, 0.43 



VIII. ALKALINITY OF INSOLUBLE ASH. 



To the platinum dish containing the insoluble ash from determination VI add an 

 excess of tenth-normal acid (usually 10 cc) and about 30 cc of water. Boil gently 

 [Cir. 40] 



