96 MAPLE-SAP SIRUP. 



such cleansing does not lighten the color as is claimed by many mak- 

 ers. The total ash is very slightly higher after cleansing, the average 

 increasing from 0.99 to' 1.01 per cent. The soluble ash also increases, 

 but the insoluble ash does not, as one would naturally expect. The 

 lead number and the malic acid value are slightly raised by the treat- 

 ment. The samples of sirup before cleansing had not been passed 

 through felt or other filters, but were allowed to settle, hence they 

 were cloudy but cleared after adding the cleansers. In order to 

 make a perfectly fair comparison of general appearance the sam- 

 ples should have been filtered and then compared with samples 

 cleansed by egg and milk. 



The percentage of nitrogen was not determined until late in the 

 investigation and some of the samples were not available for test. In 

 only three cases were the samples comparable and in these, after 

 cleansing, there was a slight increase in protein in two cases and the 

 same percentage in one. 



On the whole, >it may be said that there is no change in composition 

 of the maple sirup, other than the slight increase of protein, by such 

 cleansing, but its use is of questionable benefit since the same results 

 can be attained by filtering. 



EFFECT OF SEASONAL VARIATIONS FROM YEAR TO YEAR. 



The composition of maple sirup is said to vary from year to year. 

 Some makers note an annual variation in the amount of "niter" pres- 

 ent, while others of equal repute disagree with this statement. It is 

 true that in some years the season of tapping is much longer than in 

 others, and when a hard winter suddenly breaks into a warm spring 

 very little sirup or sugar can be made. The quantity of sap is also 

 directly influenced, seasons being the same, by the quantity of leaves 

 on the tree the year before. Should a pest of insects or caterpillars 

 destroy the leaves of the maple trees during the summer, the flow of 

 sap is diminished and the flavor of sirup and sugar produced is con- 

 siderably altered. Such a condition occurred in Franklin County, 

 Me., during the summer of 1908, and the samples collected were noted 

 to have a bitter taste not characteristic of true maple. The effect of 

 this condition on the composition of the maple sirup has not been 

 determined. 



While it is true that the extremes in determinations may be caused 

 or influenced by all of these conditions, yet pure maple sirup will not 

 fall below a certain ash content or malic-acid figure. From both the 

 physiological and chemical points of view these considerations are 

 of interest. Some six samples of 1908 maple sirup were collected 

 with the 1909 samples from individual makers and are tabulated for 

 comparison: 



