DISEASES OF PLANTS, 153 



wood. Consideration is given to shrinkage and moisture, air drying, kiln drying, 

 properties of tlie wood wliicli affect drying, causes of various effects tliat re- 

 sult from drying, and factors to he considered in overcoming the difliculties 

 in drying. 



Preservative treatment of fence posts, G. B. MacDonald {Iowa ^ta. Bui. 

 15S (1915), pp. 85-151, figs. 32). — This huUetin deals with the results of various 

 experiments at tlie station during the past 12 years on the durability of Iowa 

 fence-post woods and with methods and results of preservative treatment. 



It is considered probable that by effective creosote treatment woods such as 

 white cedar, oak, etc., commonly used for posts may be doubled in life and that 

 many species at present almost valueless, such as willow, soft maple, cotton- 

 wood, and elm can be made to last 25 or more years with only a small addition 

 in cost for treatment. It is suggested that the native soft-wooded trees be 

 selected for treatment and the oaks, hickories, black walnuts, etc., be saved for 

 other purposes. Small posts, about 4| in. in diameter, if of sufficient strength, 

 should be selected, thereby saving from 3 to 6 cts. per post on creosote. The 

 posts should be thoroughly peeled of tlie inner and outer bark and should be 

 thoroughly seasoned before treatment. The hot creosote should be kept at a 

 temperature not to exceed 220°' F., as a high temperature causes an excessive 

 loss by evaporation. The tank should contain sufficient creosote to give tlie 

 ground line of the posts a good penetration, as the thoroughness of treatment 

 just above and below the ground line is considered to determine the life of 

 the post. The penetration of creosote at the ground line of one post of each 

 lot should be tested, and the heartwood should be tested for penetration when 

 split posts are being creosoted. It is considered advisable to liave 6 in. of 

 well-preserved wood above the surface of the ground, and the tops of willow, 

 soft maple, Cottonwood, boxelder, basswood, aspen, and liickory should be treated 

 by dipping them into the hot creosote. 



A small portable tank installed on the farm or a small cooperative plant is 

 recommended. Creosote remaining after one season's treatment may be re- 

 barreled and stored for the following year's work, and a portable tank shoulc* 

 be stored or otherwise protected after the season's work. 



Report of government chemist on destructive distillation of fir waste, 

 giving- methods and results of tests made at University of WasMngton, 

 G. M. Hunt {West Coast Lumberman, 29 (1915), No. 336, pp. 26-28, figs. J,).— 

 This article gives the methods and results of tests conducted cooperatively by 

 the Forest Service of the U. S. Department of Agriculture and the University 

 of Washington, and summarizes the conclusions relative to different processes 

 of fir distillation. 



Indiana's wood-using industries, compiled by J. C. Nellis (Hardwood Rec, 

 40 (1915), Nos. 10, pp. 15-18; 11, pp. 19-21; 12, pp. l^-i7).— This comprises a 

 statistical study conducted by the Forest Service of the U. S. Department of 

 Agriculture with reference to the various wood-using industries of Indiana. 

 Data are given showing the kinds and quantity of local woods and of woods 

 from other regions used in these industries, together with the use which is made 

 of each kind of wood and the properties of the woods that especially fit them for 

 various uses. 



DISEASES OF PLANTS. 



Report of the plant pathologist, M. T. Cook (Neio Jersey Stas. Rpt. 1914, 

 PI). 461-4^6). — An account is given of the organization of the department of 

 plant pathology at the station and of the work carried on in inspection of nursery 

 stock, investigations of plant diseases, etc. 



