432 EXPERIMENT STATION EECOED. 



lY per cent by boilinj^ the solution and ahsorhins the ammonia evolved in sul- 

 phuric acid and 80 per cent in form of crystallized annnoniuni sulphate by con- 

 centrating the residutfl solution. 



In order to dispense entirely with the use of sulphuric acid, the gas liquor 

 was first treated with gypsum, the solution drawn off and treated with ferrous 

 sulphate, the precipitated ferrous sulphide removed, and the clear solution eA'apo- 

 rated to obtain crystallized ammonium sulphate. In this way it was found 

 possible to recover 05.4 ])er cent of the total ammonia. 



Further results of fertilizer experiments with agricultural phosphate, 

 H. Bachmann (Jdiir. Laiidir.. 5-'f {1906), No. 3, pp. 301-307; abs. in Jour. Cliem. 

 Soc. [London]. 90 {1906). Xo. 528, 11, pp. 702, 70,?).— Field experiments on two 

 sandy soils with rye and beets in continuation of those previously reported 

 (E. S. R., 17. p. 17) are here recorded. The results are not entirely conclusive, 

 but indicate that amorphous agricultural phosphate (fine-ground raw phos- 

 phate) is almost equal to Thomas slag in the first and second years. The ac- 

 tion of apatite ceased after the first year. 



Composition of deposits of phosphate of lime in the United States, P. 

 .luMEAT (.1;/;/. VJiini. Aniihif.. 11 (19(16). \»s. 6. ///>. 211-216: 7. p/i. 2.')6-261 ; 

 ahs. in Chcin. CoithL, 19(i6. 11. Xo. .s', p. 70')). — This is a continuation of an arti- 

 cle previously noted (E. S. R., 18, p. 22) and deals with the plate roCk, soft 

 and pebble phosphates of Florida, and with Tennessee, South Carolina, and 

 various minor phosphate deposits, including among the latter those of North 

 Carolina, Pennsylvania, Arkansas. Alabama, W.voming. Porto Rico, and Canada. 

 Statistics of ])r()duction, composition, etc., are given. 



Granite rock potash {Amer. Pert.. 27 {1906), No. 2, pp. 16. 17). — This is a 

 reprint of an article by C. G. Hopkins, of the Illinois Station, which maintains 

 that " while there is reason to believe that heavy applications of finely ground 

 granite rock carrying a considerable percentage of potassium can be used with 

 profit on certain soils, and for certain crops under suitable conditions, it is 

 unfortunate that such misleading and exaggerated statements should be made 

 as . . . are published in several daily papers." 



It is shown that 1 ton of potassium chlorid. at .f4() to .$50 per ton. contains as 

 much potash as 10 tons of granite at $3 per ton. "At .$."5 a ton for granite and 

 $.jO a ton for i^otassium chlorid, the amount nf insoluble potassium' which can be 

 purchased in a ton of granite for .$3 is no greater than the amount cf soluble 

 potassium which can be purchased in 200 lbs. of potassium chlorid for $5. The 

 fact that the granite is insoluble, and very slowly available, while the potassium 

 chlorid is soluble in water and readily available, more than coiuiterba lances the 

 difference in cost. Furthermore, the c; st cf transportation and application of 

 one ton of granite as compared with 200 lbs. of potassium chlorid will also, in 

 most cases, more than counterbalance the difference in cost." 



Experiments by the Maine and Vermont stations are cited to show that the 

 potash of granite dust and ground feldspar has a rather low fertilizing value. 



Potassium mining crisis, T. J. Albekt {Mo. Consular and Trade Rpts. 

 [r. 8.]. 1906, No. 309. pp. 77-SO).— The conditions which render it probable 

 that the combination which now controls the outimt and jirice will break down 

 are I)riefiy discussed. 



The use of lime and magnesia as fertilizer, O. Loew {Landw. Jahrl}., 35 

 {1906). No. 'i. pp. .',27-5'iO; ah.'^. in CJicni. Zt<i.. 30 {1906), No. 70, Report. No. 

 29, J). 287). — Experiments tending to show the necessity of maintaining iu the 

 soil a certain relative proportion of lime and magnesia and of keeping the latter 

 in the less injurious forms (preferably carbonate) are reviewed and discussed. 

 The importance of applying magnesia in scnne cases of excess of lime in the 

 soil is pointed out. 



