816 EXPERIMENT STATION RECORD. [Vol.40 



the soil acidity in the following order: Magnesite, dolomite, calcite, wollastonite, 

 serpentine, rock phosphate, gypsum, and enstatite. 



"The results obtained in these experiments indicate that the value of agri- 

 cultural lime is in accordance with its acid-neutralizing power, rather than 

 with the CaO, MgO, or C0 2 contained, and that the titration method is the most 

 accurate and reliable method for determining the value of agricultural limes." 



Cost of burning lime in the stack or heap, W. Fkeak and C. L. Goodi.i.n.i 

 (Pennsylvania Sta. Bui. 157 (1919), pp. 3-1$, figs. 4).— The preparation of a 

 stack for burning limestone is described and the estimated cost of the operation 

 indicated. It is concluded that the cost of assembling, erecting, and burning a 

 2,400-bu. stack of limestone already quarried amounted to 9.2 cts. per bushel 

 when team work was valued at 40 cts. per hour, man labor at 17.5 cts. per 

 hour, and bituminous coal at $2.60 per long ton f. o. b. freight station. 



Supplementary report upon the limestone resources of Pennsylvania. \Y. 

 Fbeab and C. A. Kern (Pennsylvania Sta. Bui. 151 (1919), pp. 15-28).— Analj si - 

 are given of 238 samples of Pennsylvania limestone examined during the 2-year 

 period ended April 1, 1918, supplementing a previous report (E. S. It., 38, p. 22 I. 



Calcareous marl finds increasing use in agriculture (U. S. OeoL Survey 

 Press Huh 1,10 (1919), p. /).— It is stated that "calcareous marl, a variety of 

 carbonate of lime, is finding increasing use in agriculture as a soil sweetener," 

 78,232 tons being sold for this purpose in 1918, as compared with 73,900 tons 

 in 1917 and 58.08S tons in 1916. "The value in 1918 was $2(51,082, 5S per cent 

 higher than in 1917. Besides that sold for agricultural use, 20,462 tons, valued 

 at $57,5S2, was sold for the neutralization of acid wains, the manufacture of 

 prepared fertilizers, and other uses. 



"The marl represented in this statement Includes two kinds— fresh-water 

 marl, or ooze, taken from the Ih.u. mis of lakes, ponds, or swamps, and marine 

 marl, or coquina, taken from deposits of partly consolidated masses of shell 

 fragments deposited on the bottom of a shallow sea and later elevated above 

 sea level. Fresh-water marl was produced in 1918 in Virginia, West Virginia, 

 Pennsylvania, and New York; marine marl in North Carolina and South 

 Carolina." 



Sulphuric acid and fertilizer trades (Rpt. Dept. Committee Sulphuric Acid 

 and Pert. Trades [dt. Brit.}, Complete Ed., 1919, pp. 15; rev. in Nature [Lon- 

 don], 103 (1919), No. 2578, pp. 67-69).— This is a revision of a report previously 

 noted (E. S. R., 39, p. 522). The amended report contains additional data 

 regarding the prewar production of sulphuric acid, the principal consuming in- 

 dustries and their estimated annual consumption prior to 1914, the expansion 

 of the sulphuric-acid trade during the war, the development of the zinc in- 

 dustry during the war and its Influence on acid production, the probable post- 

 war consumption of sulphuric acid, and acid factories owned or leased by the 

 Government and their condition and output. 



Of the estimated annual prewar consumption of OoO.OOO tons of sulphuric 

 acid, 300,000 tons was used in superphosphate manufacture and 2S0.000 tons in 

 making sulphate of ammonia. Extension of the fertilizer industry is pro- 

 posed as the most obvious means of utilizing the excess production of sul- 

 phuric acid. This necessitates an increase in production of ammonia and in 

 the available supply of mineral phosphates. With this in mind it is recom- 

 mended that "the Government should take immediate steps by international 

 commercial treaties or otherwise to secure an effective and permanent control 

 or command of an adequate supply of phosphate rock, and that arrangements 

 should be made in advance for the Importation of large quantities of phosphate 

 rock immediately on the termination of the war." 



