6 CONTENTS. 



Page. 



Factors influencing the character of the final product 93 



Effect of the run on the character of the product 93 



Effect of cleansing on the composition of sirup 95 



Effect of seasonal variations from year to year 96 



Comparison of sirups from covered and uncovered sap buckets 97 



Effect of environment on composition 98 



Canadian sirup as compared with United States sirup 98 



Comparison of sirups from the various States 100 



Statistics of the maple sirup industry of the United States 102 



Bibliography 104 



ILLUSTRATIONS. 



PLATE. 



Page. 



PLATE I. Standard colors by which the sirups were graded 58 



TEXT FIGURES. 



FIG. 1. Apparatus for preparation of standard caramel 15 



2. Examples of covered buckets 50 



3. Open buckets and too many of them 51 



4. Collecting tank 52 



5. Map showing effect of latitude on ash content, lead number, and malic- 



acid value of maple sirups r 101 



