DISCUSSION OF CHEMICAL DATA. 



89 



The data as a whole indicate that the ash of maple sirup is of a 

 rather constant composition. Here again the ash analysis of the 

 Canadian sirup does not differ much from that of the United States 

 product. 



LEAD NUMBER. 



The average lead numbers of the individual States vary quite 

 markedly. In the following table the States are arranged with regard 

 to the magnitude of the basic and neutral lead numbers: 



Averages by States, including Canada, of the basic and neutral lead numbers. 



The first four States stand in the same order under both headings, 

 indicating a probable relation between the precipitate formed with 

 basic and with neutral lead acetate. The remaining six States, 

 however, and Canada do not show any relation of this kind. 



The precipitate formed with the basic lead acetate is quite charac- 

 teristic, varying from white to gray in color (yellow if the maple sirup 

 is very dark) and having the appearance of being composed partly 

 of fine crystals. It settles rather quickly, without becoming compact, 

 and might be described as having a tendency to be flocculent, like 

 aluminum hydroxid. The precipitate with neutral lead acetate is 

 more flocculent, of lighter weight, and a little darker colored than that 

 formed by the basic lead, and very seldom has a crystalline appear- 

 ance. It was thought that some relation might exist between these 

 two numbers, but the investigation fails to establish this point. The 

 neutral lead figure is about one-third of the basic; dividing the basic 

 by the neutral, the average figures obtained range from 3 to 4.4. 



The average basic lead figure for the 481 samples is 2.70, figured to 

 dry substance, with extremes of 4.4 and 1.76; for the neutral number 

 the average is 0.79, with extremes of 1.65 and 0.13. Tabulating the 

 basic and neutral lead numbers by States and grouping them by differ- 

 ences of 0.25 and 0.50, the following results are obtained. 



