80 MAPLE-SAP SIRUP. 



About 41 per cent of the samples had from 0.30 to 0.39 per cent of 

 insoluble ash. Massachusetts and Vermont were the only two indi- 

 vidual exceptions, the largest divisions containing from 0.23 to 0.29 

 per cent, and 28 per cent of all the samples fell in this class, while 18 

 per cent contained from 0.40 to 0.49 per cent of insoluble ash. Rela- 

 tively few samples (12.6 per cent) have 0.50 per cent or over. Jones 

 has never found a pure maple sirup, standard in weight, with an 

 insoluble ash lower than 0.15 per cent, which, calculated to the dry 

 basis, would be 0.23 per cent. None of the figures obtained were below 

 0.23 per cent; even the one sample with 0.68 per cent of total ash 

 gave an insoluble ash of 0.26 per cent. It is safe to say, therefore, 

 that a sirup with an insoluble ash of less than 0.23 per cent is adul- 

 terated, and this figure is equally as important as the total ash in judg- 

 ing of the purity of the sample. The percentage found may be influ- 

 enced by the temperature of burning, and the calcium should be in 

 the carbonate form, as the oxid form gives too low a figure. It is 

 sometimes well to moisten the insoluble ash after the first burning 

 with ammonium 'carbonate solution, reheat, and reweigh. An in- 

 crease in weight after this treatment indicates that the oxid was 

 present, and therefore the per cent of insoluble ash will be too low 

 and that of soluble ash too high. The weight taken for determining 

 the percentage of insoluble ash in such a case should be the one 

 obtained after heating with ammonium carbonate. 



The range and average of the figures for soluble ash have been given 

 before, but as these are obtained by difference they may be affected 

 by the limit of error of two determinations. The large figure in many 

 cases can be accounted for by the fact that some makers use bicar- 

 bonate of soda or potash to neutralize the acidity and others use a 

 small quantity to raise the scum, as before mentioned. 



The figure obtained by dividing the per cent of soluble by the 

 per cent of insoluble ash has been considered important in deter- 

 mining the purity of maple products, and therefore the data obtained 

 for this ratio are given. In nearly all cases the per cent of soluble 

 ash exceeds that of the insoluble ash, the resultant quotient being 

 therefore larger than 1. There are, however, 29 exceptions to this 

 out of the 481 samples which have been tabulated. 



a This figure has been previously termed " Ratio of insoluble to soluble ash," but 

 to prevent any possible misunderstanding as to how the ratio is obtained the state- 

 ment of "soluble ash divided by insoluble ash" is made instead. 



