1878.] -^ [Price. 



/ believe Major Powell in his report, published or about to be published 

 by Government, goes into the question of destruction of forests by fire very 

 fully, and presents the case in a very strong light. 



West Chester, Chester Co., Penna., September 3, 1S78. 

 Dear Mr. Price : — Since writing to you I find the following statement 

 in a lecture by Prof. Gray of Cambridge, on "Forest Geography and 

 Archaeology" quoting from Professor Shaler of Kentucky — "Professor 

 Shaler from his observations in the border land of Kentucky thinks that 

 there are indications there of comparatively recent conversion of oak 

 openings into prairie, and now since the burnings are over, of the re- 

 conversion of prairie into woodland." The passage in the first part of the 

 quotation refers to Shaler's opinion that fires have destroyed the forests there. 

 This you know is in entire accordance with what is said on pages 276 and 

 277 of Michaux Travels, published in 1805 (Lambert's translation), of ex- 

 actly the same region. 



Sincerely yours, 



J. T. ROTHROCK. 



Professor Leo Lesquereaux has formed the opinion that the prairies have 

 failed to produce trees because of a soil inimical to their growth. This 

 theory appears to be successfully combatted by O. P. Hay in the American 

 Naturalist for May 1878, p. 299. It is also contrary to many facts stated in 

 "Sylviculture." The last page of that paper contains the conclusion of 

 O. W. Wight, in his Geology of Wisconsin, who said, " Fire has killed 

 the timber over wide areas, on which grass was growing, exhibiting before 

 our eyes nature's simple method of reconverting woodland into prairie. The 

 reverse process is just as simple. When prairies are no longer swept over 

 by fire, timber springs up, reconverting prairie into woodland. Grass, 

 with fire as an alty, can beat timber. Timber can bent grass, when it has 

 no fire to fight." We may also add that without fire to fight it can conquer 

 stones and root itself beneath the rocks, and be anchored all the stronger. 

 It is ever man that is the great destroyer, and he is competent to repair his 

 own devastation. 



Contributions from the University of Pa. , No. XV. Preliminary notice on 

 Ghromomeiry, a ueic branch, of quantitative analysis with the blowpipe. 



By Professor George Aug. Konig, Ph. D. With a plate. 



(Bead before the American Philosophical Society, Oct. 4, 1878.) 



In a former paper presented to the Society (Proceedings Vol. XVI., 

 January, 1877), I described a colorimetric estimation of titanium. Mention 

 is made in that paper of the interference with accurate results by the pre- 



