382 THE UNIVERSE. 



the water in the larger tube is rapidly absorbed by the 

 branch, and often before the end of the lesson, in the short 

 space of half an hour, the small tube is quite filled with the 

 colored liquid which was contained in the vessel. This ex- 

 periment, carried on under the eyes of the audience, gives 

 them an idea at once of the force of suction possessed by 

 plants, and of the energy of their circulation. 



The sap is formed and moves with such force in certain 

 plants that it is not uncommon to be able to extract a large 

 quantity of it in a short space of time. The sugar-maple 

 (Acer saccharinum), scattered over the hills of Canada and 

 the Northern United States, produces a bucketful in a day. 

 It is from this tree that they get the greatest part of the 

 sugar consumed in the country where it grows. 1 



For this purpose it is only necessary to pierce the tree 

 with a wimble ; the sap runs from it, and, after being col- 

 lected, is evaporated at the fire. The brown sugar con- 

 denses at the bottom of the evaporating pans. 



In the tropical countries a tree yields a product not less 

 precious to man, a wine ready made. This is nothing 

 else than the sap of a species of palm, the wine-bearing 

 sago-palm (Sagus vinifera), which grows in Western Africa, 

 and the name of which characteristically indicates the ben- 

 efits it yields. This vinous sap is mild and sweet when 

 first drawn, but a few hours afterwards it ferments, and 



1 The sap of the sugar-maple begins to rise in the month of February. In 

 order to extract it they simply bore a hole in its trunk a few inches deep, and 

 into this insert a tube, which allows the fluid to drop into a pail. When fer- 

 mented, it furnishes a light and agreeable wine, and when evaporated by a gentle 

 heat it yields a brown, viscid syrup, as sweet as treacle, which is converted into 

 little sugar-loaves. Each tree produces yearly two to four pounds. 



