MAPLE SUGAR. 



33 



and 3.49, Indiana nearly 50 per cent of samples with a lead number 

 between 3.50 and 3.74, and West Virginia no samples below 3.25. 



Ross * indicates that the excess of both lead subacetate and sugar 

 exert a marked effect upon the lead subacetate precipitate and shows 

 that the effect of the excess of sugar is relatively greater. In the 

 procedure for his method potassium sulphate is added to the solu- 

 tion before the lead subacetate to overcome the solvent action of the 

 sugar upon the lead precipitate. Ross believes this solvent action 

 to be the cause of the lead number of mixtures of maple and cane 

 sirup not being proportional to the percentage of maple present. 

 The figures by Ross lead number given herein, however, apply only 

 to sirups having a density of approximately 65 per cent solids which 

 were made up from pure maple sugar, and the application of lead 

 number determinations to mixtures of maple and cane sugar sirup 

 has not been entered into in connection with this bulletin. In 

 Table XIX the increase of the individual samples is grouped by 

 differences of 0.10 and by States. 



Table XIX. — Differences between Winton and Ross lead numbers . 



Lead number. 



Number of samples. 



Per- 

 cent- 

 age of 

 sam- 

 ples. 



Ind. 



Me. 



Md. 



Mass. 



Mich. 



N.H. 



N.Y. 



Ohio. 



Pa. 



Vt. 



W. 

 Va. 



Total. 



Winton higher than 

 Ross 

















2 









2 



1 

 9 



10 



13 



20 



34 



37 



31 



40 



37 



24 



7 



8 



3 



3 



1 



0.7 



Winton and Ross 



















1 



1 

 3 

 8 

 11 

 6 

 12 

 10 

 6 



1 



1 

 1 

 2 

 1 



1 



.3 



Ross higher by less 

 than 0.10 















1 



3 



2 

 3 

 2 

 1 

 1 

 4 

 4 

 3 

 4 

 1 

 1 



4 



4 

 2 

 4 

 8 

 8 

 5 

 4 

 1 

 1 



3.2 



Ross higher by more 

 than: 

 0.10 



1 





2 

 3 

 2 

 1 



2 









3.6 



.20 



1 

 1 

 1 

 3 

 2 

 2 

 1 

 1 

 1 

 1 







2 



5 

 11 

 10 



7 

 5 



7 



2 

 3 



4.6 



.30 







1 





7.1 



.40. 



2 



1 



12.2 



.50 



2 

 4 

 6 

 5 

 3 

 2 



3 

 3 

 4 



1 



13.2 



.60 



3 

 4 

 6 

 2 

 1 





11.1 



.70 







14.3 



.80 



1 

 1 



1 



13.2 



.90 



8.6 



1.00 



2.5 



1.10 









2 

 2 





2.9 



1.20 





1 





1.1 



1.30 











1 



1 





1 

 1 



1.1 



1.40 

















.3 



























Total 



19 



4 



11 



14 



23 



12 



54 



31 



43 



62 



7 



280 



100.0 







Difference: 



Average 



69 

 112 



48 



93 



126 



49 



38 

 92 

 16 



68 

 116 

 29 



81 

 104 

 35 



100 

 133 



74 



63 

 137 



8 



55 

 121 



50 



142 



3 



69 

 129 



50 



95 



6 























The increase varies greatly in the samples, the greatest increase 

 being 1.42 and the least 0.15. Eighty per cent of the samples show 

 an increase of from 0.30 to 1. Table XX gives the results of samples 

 that show little difference between the two numbers, from which 

 it is seen that factors other than the solubility of the lead precipitate 

 in the sugar solution enter into the amount of the lead number. 



i U. S. Dept. Agr., Bur. Chem. Cir. 53. 



