120 EXPEEIMENT STATION EECOED. 



that tlie colorimetric metbod gives a reverse indication of the amounts of 

 colloids in soils and is an unsuitable method. 



The destructive distillation of soil, E. J. Holm yard (Proc. CJiem. Soc. 

 London, 30 {WW, No. 42S, p. 109; abs. in Cliem. Abs., 9 {1915), No. 4, p. 498).— 

 By the destructive distillation of soils, a distillate of two layers was obtained. 

 The lower aqueous layer was strongly alkaline and smelled of ammonia, and 

 the upper layer consisted of small quantities of a brown oil with an odor like 

 pyridin. Qualitative tests on the lower layer showed the presence of phenol 

 and ammonia. The oil, after the addition of alkali, was distilled in a current 

 of steam, and the pale yellow distillate obtained gave qualitative tests for 

 pyridin, quiuolin, pyrrol, thiophene, and possibly furfuraldehyde. Both field 

 soils and garden soils gave similar results. More oil was obtained from garden 

 soils than from field soils. 



The results are consistent with the view that the processes of decomposition 

 occurring in the organic matter in soil are similar to those operative in the 

 foi'mation of coal. 



Electrolytic determination of the biological solution of soil, E. Panta- 

 NELLi (CentU. Bakt. [etc.], 2. Ait., J,-2 {1914), No. 15-16, pp. 439-443.)— The 

 author reports studies of the biological solution in 23 samples of desert soils 

 of Tripoli of variable composition, in which he determined the bacterial con- 

 tent of each soil and compared the results of measurements of the electrolytic 

 conductivities of percolates through these soils of water, water and chloroform, 

 0.5 per cent glucose solution, and 0.5 per cent glucose and chloroform. 



By this means it was found that the soil salts were not readily washed out by 

 water, but more so by chloroform and water in 36 cases and loss so in 7 cases. 

 With water and chloroform, after seven days at most, considerably more salts 

 were leached out than with pure water alone. Bacterial activity was only 

 slightly stimulated by added moisture, and the chloroform completely inhibited 

 the setting free of soil constituents. In 18 cases the use of the glucose solution 

 was accompanied by an increased washing out of soil salts and a marked solu- 

 tion of soil constituents, which is attributed to an increase in bacterial numbers. 

 With glucose and chloroform more salts were leached out in 7 case.9 only than 

 with glucose alone, and in 5 cases the chloroform retarded the leaching out. 

 In 11 cases glucose and chloroform caused less leaching out of soil salts than 

 chloroform alone, while in 9 cases the opix)site was observed. It is concluded 

 that chloroform increases and glucose sometimes decreases the leaching out of 

 soil salts. Chloroform in the presence of glucose completely inhibited the setting 

 free of soil constituents. 



The setting free of soil constituents varied for the most part, but not always, 

 with the bacterial content of the soil. It is thought that this power of biological 

 solution depends less on the total bacterial numbers than on the numbers of 

 individual acid and ammonia formers. 



It is concluded that the measuring of the electrolytic conductivity is a suit- 

 able method for determining the microbiological solubility of soil constituents, 

 especially when comparative experiments are conducted with and without the 

 use of chloroform and glucose. 



Contribution to bacteriological studies of the soil, A. Wojtkiewicz {CentU. 

 BaJct. letc], 2. Abt., 42 {1914). No. 10-14, PP- 254-261).— Studies to determine 

 the nature and extent of the influence of methods of management and the differ- 

 ent seasons on the microbiological processes in the soil are reported. 



The results indicate that the bacterial numbers in soils undergo no extreme 

 variations during the year. The maximum numbers were observed in the spring 

 and the minimum in the winter. The power of the soil to assimilate nitrogen 

 varied greatly with the seasons, the minimum occurring In winter and the 



