FOEESTKY. 339 



the woods of which are likely to become more or less useful in the future. 

 The work is iiiteuded especially to aid manufacturers of lumber, architects, 

 builders, and other wood users in identifying the principal oaks. For this pur- 

 pose illustrations showing enlarged transverse sections of the different woods 

 are included. An analytical key for the identification of the important North 

 American oaks, based on characters of the secondary wood, intended for the 

 use of trained students is also given. Introductory considerations deal with the 

 gross and minute structures of oak woods and the structural characters used 

 for identification. 



The bulletin concludes with a table showing the lengths and widths of wood 

 fibers of the most important North American oaks. 



Distinguishing characteristics of North American gumwoods, based on the 

 anatomy of the secondary wood, G. B. Sudworth and C. D. Mell ( U. S. Dept. 

 Agr., Forest Serv. Bui. 103, pp. 20, figs. 9).— The gross and microscopic struc- 

 ture of gumwoods, together with the characters used for identification are 

 described, and an analytical key, based on the anatomy of the secondary wood, 

 for the identification of the different species is given, together with descripr 

 tions of the different woods and their elements, including also the geographical 

 range of each species, common names, etc. 



The African rubber industry and Funtuniia elastica i" kickxia "), C. 

 Christy {London, 1911, pp. XVI +252, pis. 7^, figs. 7). — A treatise on rubber 

 culture in Africa, with special reference to the best methods of cultivating and 

 tapping Funtumia and of the preparation of its rubber, 



Manurial experiments with Hevea rubber, R. D. Anstead (Planters' Chron., 

 6 (1911), No. Jt5, pp. €90-692).— To test the effect of easily soluble and quick- 

 acting fertilizers upon the yield of latex and rubber from Hevea in distinction 

 from the efl:ect of fertilizers upon the growth of the trees, plats of 100 trees 

 each were treated with sulphate of ammonia, nitrate of soda, and saltpeter at 

 the rate of ^ lb. per tree. 



As compared with the check plats, sulphate of ammonia gave the best results 

 and the nitrate of soda the next best ; saltpeter showed a loss instead of gain, 

 although this fertilizer appeared to improve the general health of the tree. The 

 profit per 100 trees from the use of sulphate of ammonia was about $1.70 and 

 from nitrate of soda about $1.30. No definite conclusions are drawn from this 

 single experiment. 



A handbook of forest protection, G. M. Romans (Sacramento: State Bd. 

 Forestry, 1911, pp. 63, figs. 2). — ^This contains the California forest laws re- 

 lating to the prevention of fires, the protection of shade and ornamental trees, 

 and conservation measures, instructions to fire fighters, a synopsis of the game 

 laws, and a list of the fire wardens for 1911. 



The prevention of sap stain in lumber, H. F. Weiss and C. T. Barnum 

 (U. S. Dept. Agr., Forest Serv. Giro. 192, pp. 19, figs. 4). — Experimental tests 

 with various chemicals to prevent sap stain in lumber show that in commercial 

 work sap stain can be most effectively prevented by dipping the boards in 

 from 5 to 10 per cent solutions of sodium bicarbonate. The strength of the 

 solution should be determined by the severity of the conditions under which 

 the boards are to season. The chemical should be pure. 



Mercuric chlorid solutions were the most effective but being poisonous are 

 not recommended for general use. Solutions of sodium bicarbonate plus lime, 

 magnesium chlorid, calcium chlorid, sodium hydroxid, phenol, copper sulphate, 

 zinc chloi'id, and sprinkling the boards with naphthalene did not give satis- 

 factory results. 



Freshly cut sap lumber should be stacked in open piles to permit the free 

 circulation of air. Thus piled the boards season in about half the time required 

 28727°— No. 4—12 i 



