424 EXPERIMENT STATION RECORD. 



correction was therefore made for this as determined by loss on igni 

 tion. The heat evolved on moistening the soils was determined by 

 means of a Bunsen 1 ice calorimeter as improved by Schuller and 

 Wartha, 2 the method of procedure being in brief as follows: 



The soil was dried over concentrated sulphuric acid. A sample of the 

 dried soil was placed in a suitable glass vessel, which was closed with 

 a stopper carrying acapillary tube, through which the air was exhausted. 

 At the end of this operation the capillary tube was sealed and the ves- 

 sel containing the soil was cooled and placed in the inner chamber of 

 the calorimeter, which was Idled with pure distilled water. The capil- 

 lary tube was broken under water, thus letting in the water and moist- 

 ening the soil, and the rise in temperature was noted. 



The rise in temperature (uncorrected for errors in manipulation, etc.) 

 varied from 0.001 calorie (small) in tertiary quartz sand to U2.0G calories 

 in moor soils. The heat evolved appeared to be more largely influ- 

 enced by the stage of decomposition of the humus in the soils than by 

 any other factor. The more advanced the decomposition the higher 

 the temperature noted. There appeared to be no relation between the 

 heat evolved and hygroscopicity. 



It is claimed that the determination of the heat evolved when soils 

 are moistened is more easily and correctly carried out than the chemical 

 and mechanical analysis, and that it furnishes more reliable indications 

 of the actual agricultural value of soils. 



The carbonic acid of the atmosphere, Albert-Levy and H. Henkiet ( Compt. 

 Rend. Acad. Sci. Paris, 126 (1898), Xo. 23, pp. 1651-1653). 



Carbonic acid of the air, Albert-Levy and H. Henriet (Compt. Rend. Acad. Sci. 

 Paris. 127 (1S98), Xo. 7, pp. 353-355). 



On the probable occurrence of a hitherto unknown substance in the atmos- 

 phere, O. Nevvins (Ann. Pliys. u. Chem., 1S9S, No. 9, pp. 162-169). 



The purification of potable waters, P. Guichard (Bui. Soc. ('him. Paris, 3.ser., 

 1U (1898), Xo. 13, pp. 588-S92). 



Soil temperatures at Lund, Sweden (Meddel. K. Landtbr. Sti/r., 7 (1897), 

 Xo. 42, p. 1S3). — Monthly observations of the soil temperature at one-half and 1 

 meter depths for the year IS! Mi. 



On the differences in temperature of soils with and without vegetation or a 

 covering of snow, H. Wild (Separate from Mem. Acad. Imp. Sci. St. Peter sbourg, 1S9S, 

 pp.32. Leipsic). 



Moisture investigations for 1897, E. C. Ciiilcott and A. B. Holm (South 

 Dakota Sta. Put. 58, pp. 55-84, figs. J). —This bulletin records the results of the deter- 

 mination of moisture at 4 different depths in 10 tenth-acre plats subjected to 

 different systems of culture — wheat, raked, shallow culture, deep culture, and uo 

 cultivation, together with some data relating to the mechanical analysis of the soils 

 of the different plats, the meteorological conditionsof the season, and the temperature 

 of the soil at different depths. 



On the nitrogenous products which accompany humic acid in peat, F. Sestini 

 (L'Orosi, 21, p. 1; abs. in Pal. Soc Chim. Paris, S. ser., 20 (1898), Xo. 13, p. 574).— The 

 author boiled peat for several hours successively with 1' per cent sodium hydrate and 



1 Ann. Thys. u. Chem. [Poggendorff], 141 (1870), p. 101. 



2 Anu. Phys. u. Chem. [Wiedemann], n. ser., 2 (1887), p. 359. 



