Current Literature 535 



Wellhouse processes. For example, it is reported that 150,000 

 pine ties treated with 10 pounds of creosote per cubic foot gave 

 19 years average Hfe on the H. and T. C. Railway; 12,000,000 

 Douglas fir ties treated with 0.27 pound of zinc chloride per 

 cubic foot gave from 10 to 12 years average life on the Southern 

 Pacific Railway; 4,836,668 Douglas fir ties treated with 0.35 to 

 0.50 pound of zinc chloride per cubic foot gave from 10 to 12 

 years average life on the C. B. & Q. Railway; 5,631,731 hemlock 

 ties treated with 0.50 pound of zinc chloride, by the Wellhouse 

 process, gave 11 years average life on the C. R. I. & P. Railway. 

 Relatively little data are as yet available on the complete dura- 

 bility of timber treated by the Card, Lowry, or Rueping processes 

 as applied in the United States." 



S. J. R. 



The Natural Resources of an Area in Central Florida. Geol- 

 ogy and Mineral Resources. By E. H. Sellards; Vegetation 

 Types. By R. M. Harper. Separate from Seventh Annual 

 Report of the Florida State Geological Survey. 1915. Pp. 

 117-188. 



The portion of this report most likely to attract the attention 

 of the forester (although it contains much else of interest) is the 

 further elaboration of Dr. Harper's views on the relation of Long- 

 leaf pine and fire. He contends that Longleaf pine not only 

 endures fire, but is benefited by it. His reasons are as follows : 



"In the first place, in an area which had not been burned for 

 several years most of the pine seeds would probably lodge in 

 the grass and fail to germinate ; but those that fall soon after a 

 fire, when the ground is bare or nearly so, take root readily, 

 especially if they fall where the soil has just been loosened up 

 by salamanders (which seem to be most active just after a fire). 

 It can hardly be doubted that fire also tends to keep in check 

 some insects which would otherwise injure the trees, but this 

 point does not seem to have been specially investigated. 



"Second, fire returns quickly to the soil the potash and other 

 minerals stored up in pine straw and other dead leaves, and thus 

 allows the pine to do a large business on a small capital, so to 

 speak. For the soil is not very rich in soluble minerals, and 

 these when taken up by plants are concentrated chiefly in the 



