22 BULLETIN 1107, U. S. DEPARTMENT OE AGRICULTUEE. 



number of sections of infested wood were treated with various repel- 

 lents and poisons and covered with various alloys, metals, and other 

 promising materials in such a manner that these would have to be 

 penetrated before emergence could take place. Usually the sections 

 were dipped in the liquids, painted with the heavier fluids, and 

 rolled up into or covered with the metals. In all cases parts of the 

 sections were left untreated or uncovered to serve as checks. 



The following materials were used during the various tests from 

 year to year (1918 to 1920) : Beef tallow; a commercial brand of re- 

 fined paraffin ; a mixture of the tallow and the refined paraffin ; arse- 

 nate of lead ; a water solution of sodium silicate similar to " water 

 glass"; creosote; No. 38 varnish; spar varnish; tire tape (the com- 

 mon friction tape used by electrical workers) ; tarred building paper; 

 commercially pure lead sheathing (referred to as "No. 1 lead"); 

 lead-antimony-tin sheathing, or " No. 2 lead " (95 per cent lead, 4.5 

 per cent antimony, 0.5 per cent tin) ; lead-antimony, containing 94 

 per cent lead and 6 per cent antimony) ("No. 2a lead") ; lead-anti- 

 mony, containing 99 per cent lead and 1 per cent antimony (" No. 3 

 lead"); lead-tin, containing 97 per cent lead and 3 per cent tin 

 ("No. 4 lead") ; commercially pure lead embedded with emery fil- 

 ings ; lead carborundum coated ; lead copper coated ; lead tin coated ; 

 zinc 0.01 inch thick ; and sheet steel 0.006 inch thick. 



After being treated the sections were placed in the open laboratory 

 under conditions of normal temperature and moisture. All of the in- 

 festing insects seemed to have transformed naturally and carried on 

 their regular functions in a normal manner. 



Attacking ExpePkIments. 



As it was realized that the insect probably would put forth every 

 effort to emerge and that to do this it might go through repellents 

 and other substances which it would not otherwise attack, a number 

 of uninfested sections of oak and other woods in the proper condition 

 for attack were treated and exposed to attack. The following mate- 

 rials were used to treat these sections: Arsenate of lead paste, black 

 paint, P. & B. paint (a protective paint used by the telephone 

 company workers), pine tar, black iron enamel, white porcelain 

 enamel, creosote, carbolineum (a high grade of coal-tar creosote), 

 nicotine sulphate containing 40 per cent of nicotine, a solution of 

 sodium silicate, a refined paraffin, two grades of a commercial chlorin- 

 ated naphthalene compound, beef tallow, and varnish. 



In order to get a good check on the action of the substances used, 

 untreated sections of wood were kept under the same conditions as 

 the treated sections. Some of the sections were left exposed in the 

 open laboratory where numerous beetles were flying every day during 



