500 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



After removing the wood from the vats it should be carefully wiped 

 off with cloth. The resultant color will be somewhat darker than the 

 color of the untreated wood; care m.ust be exercised in thoroughly 

 cleaning the surface of the wood to insure the proper adherence of 

 shellac or varnish. 



The amount of wax taken up in the above treatment will vary with 

 the different species of woods — whether they are open-pored or not — 

 and according to the condition of the wood to be treated. A representa- 

 tive groups of both softwoods and hard woods' were treated with chlorinat- 

 ed naphthalene for our tests. This treatment renders the wood both 

 white-ant-proof and moisture-proof to a marked degree. When treated 

 with chlorinated naphthalene these sample sections of North American 

 hardwoods, susceptible to attack if untreated, were not attacked, after 

 burial in the ground for over three years with logs infested with white 

 ants or termites {ReticuUtermes spp.) in Virginia. After this severe 

 test in the ground these treated woods compared favorably with untreat- 

 ed teak and mahogany as to general condition. 



Similar samples of woods treated with paraffin wax were readily attack- 

 ed by white ants and also suffered decay. 



Chemical Treatments for Crude Forest Products 



Construction timbers or other timber which is to be in contact 

 with the ground should be impregnated with coal-tar creosote, which is 

 a permanent preventative against attack by our native white ants or 

 termites. Coal-tar creosote has many properties which would rec- 

 onunend its use in this respect, for it is also a fungicide, and, being 

 insoluble in water, will not leach out in wet locations. These require- 

 ments furnish objections to many chemicals that otherwise are very 

 effective insecticides. 



The various methods of superficially treating timber, as by charring, 

 by brushing, or by dipping with various chemical preservatives, among 

 which are coal-tar creosotes, carbolineums, etc., have proven to be 

 temporarily effective in preventing attack if the work is thoroughly 

 done. 



If the wood is not in contact with the ground, impregnation treatments 

 with bichlorid of mercury and zinc chlorid are effective. The mercury 

 and zinc in this form are both soluble in water. 



^White pine {Pinus strobus), black walnut, sweet birch {Betiila lenti), chestnut, 

 white oak {Quercus alba), red oak {Quercus rubra), sweet gum {Liquiiimbar slyraciflua) 

 mahogany {Swietenia mahogoni), sugar maple {Acer siccharum), white ash {Fr. ixinus 

 ameticana). 



