336 STATE POMOLOGICAL SOCIETY. 



and eight ounces, Avliile one spout in a similar tree flowed less than half as 

 much, or thirty-five pounds and two ounces. There can be no doubt that the 

 quantity of sap obtained from a tree by the use of many sprouts is greater than 

 that from a limited number, but it is not likely to contain so large a per cent 

 of sugar. Still, if it be true, as seems probable, that the withdrawal of sap ex- 

 erts no deleterious influence upon the health and vigor of a tree, and the sap 

 is richest early in the season, it would seem best to insert more spouts, and so 

 extract the sugar in its purest condition as rapidly as possible. This, of course, 

 would necessitate a greater expenditure for buckets, which might possibly 

 counterbalance the advantages of the new method. Experiments might be 

 easily instituted to determine the facts in regard to this matter by any intelli- 

 gent sugar-maker. 



In regard to the origin of cane sugar in the sap of the maples, the butternut 

 and the black walnut, we must, for the present, admit that we have not yet 

 discovered it ; though the singular fact that the species which yield this sugar 

 belong to that class of trees which only flow freely after severe frost seems to 

 indicate that freezing and thawing may have some influence upon its produc- 

 tion. 



COMPOSITION OF SAP. 



It will be seen from an examination of the table relating to the composition 

 of saps, that the sap of the wild grape is almost pure water, and that it con- 

 tained, on the fifteenth of May last, no trace of either cane sugar, glucose or 

 starch. There is, however, in the wood of the roots and stems of the genus 

 Vitis, a great quantity of a colorless, translucent, almost tasteless mucilage, 

 which is abundantly exuded from the pores of a cross section made at any time 

 when the roots are dormant. Very little even of this seems to escape from a 

 bleeding vine, wiiich may account for the fact that the flow" of crude sap from 

 the grape does not perceptibly afi"ect its subsequent growth or productiveness. 



THE SAP OF THE SUGAE MAPLE 



contains from two to three per cent of cane sugar, while that of the red maple 

 yields only about half as much. The sap of the latter is said by Mr. H. M. 

 Sessions, of Wilbraham, also to contain some ingredient which attacks iron, 

 forming a very dark-colored syrup when evaporated in pans of that metal. It 

 is, therefore, better to exclude it from the sap gathered for the manufacture of 

 sugar. 



In order to obtain as much information as possible in regard to the sap of 

 the sugar maple, an analysis was made of the gas contained in the tree when 

 first tapped. This was procured by inserting a stopcock into the sap-wood of 

 a tree twenty feet from the ground. To the stopcock was attached a glass tube 

 by means of a rubber connector, and the tube passed through a cork into a 

 large bottle, reaching to the bottom. As soon as the bottle was filled with sap, 

 it was tightly closed and taken to the laboratory, where the gas was separated 

 by boiling. The analysis shows that the gas contains much less nitrogen and 

 more oxygen than atmospheric air, while the proportion of carbonic acid gas 

 is about one hundred and thirty-four times greater in the former than in the 

 latter. 



As we do not know how or when the cane sugar is formed in the maple, we 

 cannot account for the variations in the sweetness of its sap, which are, how- 

 ever, very great. As the flow depends upon the freezing and thawing of the 



