AVAILABILITY OF POTASH IN GROUND ROCK. 25 



year we had fertilized heavily with carliouatc uf iiotash. I wiU he pleased to 

 give you more detail if you wish. 



Yours resiieotfully, • .7. S. Dkwkv. 



Hartforu, Conn.. Fchruiuy 7, 1907. 



Dear Sir : In reply to your letter of Fehruary 5 regarding the finely gx'ound 

 spar, would say that we used this material as a potash fertilizer as directed hy 

 you last spring. This was used on eomiiaratively new land, tobacco having been 

 grown only one season previous to this past .season. During the growing season 

 we could not see any perceptible difference ou the same laud between this 

 tobacco and that treated with carbonate of potash, planted side by side. We 

 hung this toI)acco in the sjanie shed, it being cut at the same time, where we 

 were able to identify it after it was cured. We are glad to report that the 

 tobacco grown where the ground feldspar was used was exceptionally nice 

 tobacco. It was so pronounced by tobacco experts who have examined it. 



The tobacco grown on the same ciiaracter of land beside where this was 

 grown was exceptionally luce tobacco, but we thinlc if there was any preference 

 it would be for that grown on the feldspar. It certainly was beautiful in 

 eyery respect. We should be very glad to conduct an experiment ou 1 acre or 

 less on new land that has never grown croi)s of any kind or been fertilized in 

 any way by stable manure or other fertilizer, and follow this up for, say, three 

 years. We havg a piece of laud we think well adapted to make the experiment. 

 The result this past year has been so gratifying that we would be very glad to 

 carry it a little further, if possible. 



Any furtlier information we can give you we will be glad to furnish. 



Yours truly, Olds & Whipple. 



SuFFiELD, Conn., Fehruary 16, 1907. 

 Dear Sir : Yours received inquiring about the finely ground feldspar sent me. 

 Would say that I used it on 1 acre of tobacco and got very satisfactory growth. 

 The only difference I could detect in tobacco grown on this acre and the adjoin- 

 ing land, where I used cotton-hull ashes for potash, was that the burn of the 

 tobacco grown on the latter was not quite as clear as that of the tobacco grown 

 on the feldspar. 



Yours respectfully, Edmund IIalladay. 



QuiNCY, Fla., March 7, 1907. 



Dear Sir : In reply to your favor. I beg to state that 1 acre of tobacco was 

 grown here last year on ground feldspar, and as far as we were able to tell from 

 the appearance of the tobacco in the field the growth was equally as good as 

 where other forms of potash were used. Mr. Underbill, who used this feldspar, 

 was not able to harvest the tobacco separately ou account of scarcity of labor in 

 harvest season. 



I am planting some plat experiments this year in which I have included the 

 ground feldspar, to be compared with other forms of potash, and hope to get 

 some information in this way. In addition to this I shall put out at least 2 acres 

 of feldspar as a substitute for carbonate of potash, and will report results at the 

 end of the season. 



Yours very truly, W. W. Cobey. 



Although it is admitted that tliese experiments have not as yet 

 proved the vahie of ground feklsj^ar for tobacco, it is quite certain 

 that the experimental crops found all the potash they required. If 



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