26 



the ground, from lack of proper cover, is more exposed to undesirable 

 extremes of temperature during the sap season. The maple is a for- 

 est tree, and should grow under conditions that approach as nearly 

 as possible those of the forest, but there is no reason why the grove 

 can not be so worked that large, full-crowned trees shall occupy the 

 ground and at the same time keep the soil sheltered and the forest 

 cover perfect. 



THE AMOUNT OF SUGAR IN MAPLE SAP. 



Maple sap is a nearly colorless liquid composed of water, sugar, and 

 various mineral substances, such as lime, potash, magnesia, and iron; 

 it also contains some organic matter in the form of vegetable acids. 

 The peculiar flavor of maple sugar comes, not from the sugar, but 

 from some one or a combination of all the other substances contained 

 in the sap. 



The amount of sugar in the sap of the average sugar maple tree 

 varies greatly, the percentage changing in each tree as the season pro- 

 gresses. Careful experiments have shown that the sap contains on an 

 average about 3 per cent of sugar. The maximum is reported at 10.2 

 per cent, which was found in a small flow of sap from a sugar maple 

 near the end of a season, during which the tree averaged 5.01 per 

 cent. 



THE MANUFACTURE OF SUGAR AND SIRUP. 

 IMPROVED METHODS. 



The increased demand has brought about the introduction of eco- 

 nomical methods in manufacture in sharp contrast with the primitive 

 methods which once prevailed and which still persist where produc- 

 tion remains on a small scale. The auger hole and the closed metal 

 spout have been substituted for the old destructive ax cut and open 

 wooden spout. Similarly, tin or galvanized-iron pails have gradually 

 taken the place of the rough wooden troughs which formerly caught 

 the sap. 



At first the sap was generally carried to the fire or sugarhouse in 

 buckets by hand or with a shoulder yoke. Occasionally a barrel and 

 sled, drawn by an ox team or horses, were added to the gathering 

 outfit. But as the scale of operations increased, the gathering tank 

 was introduced and is now used in all but the smallest groves. Where 

 the work is on a large scale, pipes are often run through the bush, as 

 the grove is sometimes called, connecting with the sugarhouse or with 

 large storage tanks on the roadside, while in one large Adirondack 

 sugar grove a narrow-gauge railway is used for collecting sap. 



a Dr. H. W. Wiley: Bui. No. 5, Bureau of Chemistry, U. S. Department of Agriculture. 



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