MAPLE SUGAR. The manufacture of maple sugar is carried on more or less wherever sugar maple trees are abundant, especially in the Northern Atlantic and Northern Central States, the leading producers, according to census re turns, being Vermont and New York. In some cases the natural groves have been extended by planting. The busy period depends upon the locality and upon the season, sometimes com in February and sometimes lasting until the middle of May, the best flow of sap being when there is a diurnal alternation of thawing and slight freezing. See MAPLE.
The most popular modern method of tapping the trees is to bore a one-half inch hole not more than inches into the tree near the ground and to drive in a metal or wooden `spile.' This conducts the sap and also serves to support the bucket, from which the sap is collected once or oftener each day and taken to a central plant to be boiled as soon after it arrives as possible, to avoid deterioration. All sorts of apparatus, in cluding culinary utensils, are used for boiling the sap, but the most approved is a steam-heated evaporator, of which several makes are upon the market. In these the sap flows through a wind
ing channel, emerging as the finished product. which, owing to its freedom from molasses, quickly solidifies if sufficiently evaporated.
On an average the sap contains about 3 per eent, of sugar, hut occasionally exceeds 6 per cent., and at this average a yield of three pounds a year is considered profitable. Large trees and trees with rich sap often yield far more. The impurities of the sap as found in the sugar rarely exceed 5 per cent. There is, however, a small amount of insoluble material which is re moved by skimming. Sometimes milk or white of egg is used as a clarifier, but usually no puri fying agents are employed. reliance being placed on quick boiling and skimming to produce a light colored and otherwise satisfactory sirar. The only impurity that causes trouble is the so-called `sugar sand.' composed mainly of acid malate of lime, which collects on the bottom of the pans, interferes with the boiling. and makes the syrup cloudy and the sugar gritty.