SAP 67 



\y. It contained, in very small quantity, acetate of lime, acetate 

 of potash, acetate of alumina, extractive matter, tannin acetic acid, 

 ind gallic acid. 



The sap of the chestnut-tree^ according to Vauquelin, who, foi 

 want of a sufficient quantity of the fluid, was able to study it hut 

 very superficially, contains mucilage, nitrate of potash, and the 

 acetates of potash and lime. 



The sap of the elm was examined at three periods ; first, at the 

 commencement of April, then some days after, and lastly, a month 

 later. At the beginning of April its color was yellow, its taste 

 sweet and mucilaginous ; it was scarcely acid. Analysis indicated : 

 water 1027.90, acetate of potash 9.23, organic matter 1.06, carbo- 

 nate of lime 0.80. 



At the second period it contained a little more extractive organic 

 matter, and a little less carbonate of lime and acetate of potash. 

 The last examination showed that these two salts had still further 

 diminished in quantity. When exposed to the air, the sap of the 

 elm undergoes decomposition, and becomes alkaline : the acetate of 

 potash passes into the state of carbonate. 



M. Regimbeau found in the sap of the vine* bitartrate of potash, 

 tartrate of lime, mucilage, and free carbonic acid. 



The sap of the maple-tree contains a very considerable quantity 

 of sugar. In Canada, this sap, properly treated, yields sugar which 

 is identical with that of the cane. The nature of the sap is subject 

 to variations ; and Duhamel slates, that at a certain season it loses 

 its saccharine taste, and acquires an herbaceous flavor. f 



Liebig and Will detected the presence of ammoniacal salts in the 

 sap of the maple and birch-tree, and in the tears of the vine. M. 

 Biot examined the sap of a considerable number of trees, and ascer- 

 tained that the sugar in them often exists in two different states ; in 

 that of cane-sugar, properly so called, and in that of grape-sugar, 

 which, as chemists admit, diflTers from the former only in the pos- 

 session of an additional equivalent of water. The saps which M. 

 Biot examined, contained besides some animal matter {albumine) 

 and a gummy matter ; he found no free carbonic acid. The object 

 .whichlie had in view, namely, to study the changes which occur m 

 the nature of sugar, did not lead M. Biot to notice the minute quan- 

 tities of salts with organic acids which Vauquelin met with in saps. 



The trunk of a walnut-tree, tapped on the Uth of February, 

 yielded a sap containing some cane-sugar. The saps of the syca- 

 more, of the acer negundo, and of the lilac-tree, contained the same 

 species of sugar ; but that of the birch-tree held in solution some 

 grape-sugar. In the sycamore and birch-tree, M. Biot observed 

 an extremely interesting fact. He ascertained, on felling these trees, 

 that the greater portion of the descending sap was accumulated to- 

 wards the middle of the trunk. That of the birch-tree was acid 

 and saccharine ; the sap of that portion of the trunk which was 



* Journal de Pharmacie, t. xviii. p. 36. 



t Annales de TAgriculture, Franfaise, t. v. 26me s6rie, p. 339. 



