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 withdrawn and the hole sealed up.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. 



