OF THE ASH-LBAVED MAPLE. 43 



This gives an average of 2.V4 grammes of crude sugar to 100 c.c. of sap, or (taking 

 1,010.4 as the average specific gravity of the sap) 2.12 per cent. According to this, 3.67 

 gallons of sap vrould be required to make one pound of crude svigar. 



The sugar produced by evaporating the sap in a porcelain basin w^as much lighter 

 in colour than ordinary maple sugar, and it was found that the sap of both the sugar 

 maple and the red maple, vphen evaporated under similar circumstances, showed a 

 much greater tendency to darken than did that of the neguudo. The neguudo sugar 

 has an agreeable taste and odour, neither, however, being so marked as in the case of 

 ordinary maple sixgar, or of that made from the red maple. 



On boiling down the negundo sap, a white pulverulent substance was deposited, the 

 quantity being very small at first, but increasing somewhat during the last few days of 

 the "run." As is well known, a similar deposit is obtained in making ordinary maple 

 sugar, and is sometimes spoken of as "nitre" by farmers. This so-called nitre has 

 repeatedly been stated to consist of calcium malate. The deposit from the negundo sap, 

 when examined under the microscope, proved to be entirely amorphous. On heating in 

 a platinum crucible it blackened, and the residue effervesced readily with hydrochloric 

 acid. These reactions may have been due to the presence of calcium malate, but analy- 

 sis has shown that no less than 64.91 per cent, of the deposit consisted of tricalcium 

 phosphate. A similar deposit otaiued from the sap of Acer rubruin also contained a large 

 proportion of calcium phosphate, and I have little doubt that if the " nitre " from the 

 sap of Acer saccharinum were examined for phosporic acid, it would here also be found to 

 be a prominent constituent. 



The foregoing observations with regard to the ash-leaved maple, it should be borne 

 in mind, relate to only two trees grown at Montreal, and, obviously, it would not be wise 

 to draw general conclusions from them. The facts, however, have been deemed worth 

 recording, and probably embrace most of what is known on the subject. The total quantity 

 of sap obtained was small, but the trees were too young for tapping, and, besides, it was a 

 very " poor year " as regards flow of sap from the true sugar maple. In fact, a fine and 

 large specimen of the latter (on the grounds of McGrill College), which was tapped at the 

 same time as the negundos, yielded proportionately a much smaller quantity of sap. 



Concerning the proportion of sugar in the sap of Acer saccharinum, the most diverse 

 statements occur. This no doubt arises from the fact that the quantity of sugar varies in 

 different trees, different years, and different localities ; and, besides, so far as I can learn, 

 comparatively few careful analyses have been made. Weiss gives 3 per cent, as the 

 quantity found in one locality, but says that 5 to 6 per cent, may often be obtained 

 Goodale gives 8 per cent, as the average ; but this is obviously a mistake.^ C. "Wellington 

 found 2.111 per cent, in the sap of a sugar maple on the 26th and 28th of March, 1874.^ 



The specimen of Acer saccharinum on McGill College grounds, referred to above, was 

 found to yield a very sweet sap, the examination of which, on three successive days, 

 resulted as follows : — 



' Physiological Botany, p. 360. 



' Twenty-second Annual Report, Massachusetts Board of Agriculture, Boston, 1875, p. 290. 



