REPORT ON THE CAOUTCHOUC OE COMMERCE. 
35 
impoverishes the tree, and predisposes it to succumb to atmWpheric 
changes, and to the attacks of insects, for healthy trees are not so 
liable to these latter destructive agents, and very seldom does a 
tree so injured long survive these united influences. * 
Mode of Tapping*— hi temperate climates, the only tree which 
is tapped for its juice is the sugar maple {Acer saecliarinum , L.) 
This is tapped with an auger inch in diameter. The trees are 
perforated with two holes, four or five inches apart, in an oblique 
ascending direction, 18 or 20 inches from the ground, care being 
taken that the perforation does not enter too deep. The sap is 
allowed to run down small channels consisting of split elder stems, 
&c. When these precautions are taken the tree is uninjured, the 
wood alone being somewhat softer and less .durable, as is the case in 
the wood of all “ tapped ” trees. 
Prom the Manna Ash of Calabria and Sicily '(Fraximis ornus 3 L.) 
the sweet concrete exudation known as Manna is obtained by 
incisions in the bark of the tree. The tree is not tapped till it has 
ceased to produce new leaves. Cross or transverse cuts about 
2 inches long are made with a hooked or curved knife. This is only 
done on one side in the season. The following year the incisions 
are made further round the tree so that in three or four years the 
first line of cuts is returned to (Pig. 3).* 
Fig. 5. 
* Taken from a .specimen collected in Calabria by D. Han bury, Esq., F.R.S., and 
kindly lent me by him. 
