APRIL. ' 73 
sugar cool in vessels, without either disturbing it_, or draining 
off the molasses, so that it becomes a mass, nearly as hard 
as rock, and very dark in colour. 
C. — The maple is a very useful tree ; does any other 
species produce sugar ? 
F, — The White Maple {Acer Eriocmyon ?) yields sap 
more readily than the Rock Maple (J. Saccharinum), and 
it is said to be more abundant in sugar ; but it is compara- 
tively rare as a large tree. The Butternut (^Juglans Cinerea) 
likewise will yield sugar from its sap, and probably other trees. 
The Birch {Betida Papyracea) is often tapped, and the sap, 
(evaporated by boiling) exposed to the summer's sun, by 
which it is made into a good vinegar ; whence I conclude it 
must contain sugar, probably mixed with other matters. The 
fresh sap of the birch has a pleasant, slightly acid taste. It 
has a curious property, peculiar to itself, I believe, for I have 
never observed it in the sap of any tree but the birch ; where- 
ever it flows, it leaves a mass of fungus-like, mucilaginous 
substance, of a delicate pink hue, which probably has some 
affinity with what is called " the mother" in vinegar. From 
the stumps of trees which have been felled during the winter, 
the sap flows in spring so profusely, that I have seen them 
covered with this substance, — a great resort of insects. 
(7. — How large must the maple become before it will 
yield saccharine juice ? 
F. — The sap contains sugar from the first period of its 
existence, but it is not usual to tap a tree until it attains 
about the diameter of a foot at the bottom ; too early tap- 
ping is injurious to the health of the tree, and causes prema- 
ture decay ; old trees, too, produce lil^le or none, and are 
cut down for fuel. ^ 
C, — Is there never more than one incision made in a 
tree at one time ? 
jP. — With us there is no more ; but in the United States 
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