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Page:Popular Science Monthly Volume 90.djvu/931

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Popular Science Monthly

��915

��Killing the Insect Pests of Trees with Poisonous Gas

FUMIGATION is suc- cessfully employed by the Forest Service to combat borers and like insect pests that damage shade trees. The fumi- gating agent used is car- bon disulphide, which, in the case of small trees, is injected into the openings by which the borers have entered. The hole then is sealed up with clay and the deadly gas from the chemical eventually makes its way into every cavity, killing all of the pests within its reach. The fumigation process does not injure the tree.

Large trees which the pests have entered through decayed places around the base require a certain amount of preparation. The holes in the base of the tree are first covered over with tarred roofing paper, cotton wool being employed to insure as tight a joint as possible. An opening just large enough to admit the end of a syringe is then cut in the paper shield. After a sufficient quantity of the chemical has been injected to insure thorough fumigation, the syringe is withdrawn and the hole sealed up.

The paper is left about the base of the tree until the gases from the chemical have permeated every borer hole and crevice. Then the shields are removed and all of the decayed wood within the opening is cut away. These holes are then filled up with cement. In this way many years are added to the life of a tree, which, otherwise, would have perished in a comparatively short time. The plan has been found to be effect- ive in the cases of trees deemed almost utterly hope- less on account of the num- ber of borers and the extent of their de- structive work.

Very shortly after the fumigation and jKitching-up opera- lions the trees begin to leaf out in new- ness of life.

���Injecting the chemical in a tree through a roofing-paper shield

���This Type of Bottle-Stopper Is a Fraud Detector

AS a means of protec- tion to dealers having an individual trademark and to prevent their bot- tled goods from being tampered with by the unscrupulous, the bottle- stopper recently invented by James Allen, of Wash- ington, D. C., meets a specific need.

As shown by the illus- tration it consists of an ordinary tapered cork with a flexible wire or cord passing through the center. At the end of the wire is a plug. The plug has a flanged head. When the wire- is pulled the flange strikes the cork so that the plug cannot be pulled out. The cork is used in connection with two protective seals, one seal being wrapped around the neck of the bottle and pasted to it, and the other being secured to the top of the bottle. A part of the pulling cord is held beneath the seal on the top of the bottle and the ends are held down under the other seal. It is therefore impossible to pull the string in order to open the bottle without mutilating the seal or -the lead-foil cup.

When this stopper is used it is pushed dow^n flush with the top of the bottle so that no part of it projects. By pulling the cord the seals or any lead foil capsules which may be used instead of seals, are broken through and the stopper removed without a cork screw or other aid. The end of the looped cord may be entirely concealed beneath the lead foil or it may pro- ject a little in order that it may be more readily found when It is impossible needed. Lead-foil caps to remove the ^^ seals mav be used stopper without , i " -^i i

mutilating the as preferred, with equal seals or foil cap satisfaction.

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