106 



PROPERTIES OF WOOD. 



in his classical works referred to below.* Kegarding " dry 

 rot" Goppert and Hartig have published treatises.! 



[The International Association for Testing Materials, Decem- 

 ber, 1898, formulated two questions regarding dry rot : 



1. Can infection of wood by Mer alias lacrimans be recog- 

 nised before it is used ? 



2. What are the best methods of preserving the wood ? 

 The former question has not yet been answered. For the 



second thorough drying and painting the wood with antiseptics 

 suffices. Creosote is the best antiseptic, but is inflammable. 

 Vide Henry, Eev. das E et F, page 65, 1901, and September 1, 

 1902. In order to test the comparative durability of certain 

 woods Hartig placed heartwood beams 10 C. in diameter, of 

 the following species in the ground. The years given in the 

 statement below denote the period in which the wood was 

 completely rotten. 



In the damp, warm air of mines, some experiments made 

 at Commentry gave the following results for pit-props, the 

 species being arranged in their order of durability | : 



1. Oaks. 



2. Scots pine. 



3. Alder. 



4. Ash. 



5. Maritime pine. 



6. Eobinia. 



7. Willow. 



8. Maples. 



9. Elm. 

 10. Aspen. 



11. Cherry. 



12. Birch. 



13. Hornbeam. 



14. Beech. 



15. Poplar. 



* 11. Hartig, ;i Die Zerset/ungserscheinungen des Holzes der Nadelhol/batime 

 u. der Eiche." Berlin, 1878. " Lehrbuch der Baumkrankheiten," 3 Autl. 

 I'.crliii, is;)!). See also, " Schlich's Manual of Forestry," vol. iii. " Forest Pro- 

 tection," by \V. 11. Fisher, 2nd ed.. IIMMJ. 



f Clipper!, "Der Ihtnssc.liwainm." I'.reslau, 188">. 11. Hartig, ' Der Hans- 

 scluvamm." I'.crliii , iss:,. 



J These data are given by Mathey, oj>. cil . 



