Domestic Encyclopædia (1802)/Supplement/Elm-trees

ELM-TREES are frequently subject to a kind of ulcers; which, if not timely attended to, eventually destroy them. Such as are planted in marshy grounds, or in the vicinity of rivers, are chiefly liable to this distemper: the ulcer generally appears on the side exposed to the south, and at a little distance from the root; though it sometimes occurs five or six feet above the surface.

The cause of this disease was, by Du Hamel, supposed to be a superabundance of sap; which conjecture has lately been corroborated by the experience of M. Bourchier. In order to cure the trees thus attacked, the latter pierced the ulcer with an auger, and afterwards fitted to the hole a tube that penetrated to a sufficient depth. He observes from experience, that the trees thus affected, yield a larger proportion of sap in serene than in tempestuous weather; and accordingly as the wound is more or less in a southern exposure: after two or three days, the sap-flow ceases, and the wounded part spontaneously heals.