246 SOIL SCIENCE [Bot. Absts., Vol. IV, 



organisms are normally present and can be rendered more effective only by making the soil 

 more favorable for their growth and activity. — E. G. Anderson. 



1642. Briscoe, Charles F., and H. H. Harned. Bacteriological effects of green manure. 

 Study No. 11. Mississippi Agric. Exp. Sta. Bull. 185: 8 fig. 1919.— See Bot. Absts. 4, Entry 36. 



1643. Conn, H. J., and J. W. Bright. Ammonification of manure in soil. New York 

 Agric. Exp. Sta. [Geneva] Tech. Bull. 67:3^5. 1919. — A reprint of article in Jour. Agric. 

 Res. 16:313-350. 1919. [See Bot. Absts. 3, Entry 850.] 



1644. Fred, E. B., W. H. Peterson, and A. Davenport. Acid fermentation of xylose. 

 Jour. Biol. Chem. 39:347-384. PI. 1. 1919. 



1645. Fred, E. B., and E. J. Graul. Effect of inoculation and lime on the yield and on 

 theamountof nitrogen in soy beans on acid soil. Soil Sci. 7: 455-467. Fig.l. 1919. — Inpotand 

 field experiments on sandy soils inoculation increased the yield of dry matter of soy beans 

 which was further increased by the application of lime. On the silt loam used inoculation 

 did not increase the yield but increased the per cent of protein in the crop. In a pot experi- 

 ment in which the soil and crop were analyzed 323.5 pounds of the nitrogen in the plant on an 

 acre basis came from the air and 130.4 pounds of nitrogen from the soil inoculated but un- 

 limed. When limed and inoculated 389.0 pounds of nitrogen came from the air and 122.7 

 pounds from the soil. — William J . Robbins. 



1646. Noyes, H. A. Accurate determination of soil nitrates by phenol disulfonic acid 

 method. Jour. Indust. Eng. Chem. 11 : 213-218. 1919. — Investigations to overcome the errors 

 in the colorimetric (phenol disulfonic acid) method to determine soil nitrates are reported. 

 The method is adapted to the accurate determination of soil nitrates in large as well as in 

 small amounts. — H. Schmilz. 



1647. Robbins, William J., and E. C. Lathrop. The oxidation of vanillin to vanillic 

 acid by certain soil bacteria. Soil Sci. 7: 475-485. Fig. 1. 1919. — Vanillic acid was isolated 

 from solution cultures containing nutrient mineral salts and vanillin and inoculated with a 

 pure culture of a soil bacterium. In solution cultures vanillin is rapidly oxidized to vanillic 

 acid by this bacterium. The vanillic acid at first accumulates in the culture solution but is 

 later destroyed. — William J. Robbins. 



1648. Vass, A. F. The influence of low temperature on soil bacteria. Cornell Univ. 

 Agric. Exp. Sta. Mem. 27: 1039-1074. 1919. — The freezing of soils containing bacteria result? 

 in an increase in the bacterial count as determined by the agar-plate method. The author con- 

 cludes that this is due to the fact that freezing and thawing results in breaking up the clump? 

 of bacteria and not to any actual increase in the number of bacteria. The fact that freezing 

 in salt and ice at — 15°C, or in liquid air at — 190°C. for short periods, ranging from one min- 

 ute to two hours, may result in increasing the bacterial count more than 100 per cent is given 

 as proof that no bacterial growth occurs. The temperature of the water used in making the 

 dilution and the rate of thawing seem also to have a marked effect on the bacterial count from 

 samples of frozen soil, an increase in number accompanying an increase in temperature of the 

 water up to about 30°C. When pure cultures of the non-spore-producing Bacillus radicicola 

 were frozen in nutrient solutions in sand, in soil, and in solutions containing different con- 

 centrations of glycerin or glucose it was found that the presence of sand, soil or solutes offered 

 considerable protection against the destructive effect of the freezing, and the higher the con- 

 centrations of the solutes, the greater was the protection. [See Bot. Absts. 4, Entry 1592.] — 

 Otis F. Curtis. 



SOIL ACIDITY 



1649. Conner, S. D., and H. A. Notes. Natural carbonates of calcium and magnesium 

 in relation to the chemical composition, bacterial content and crop-producing power of two very 

 acid soils. Jour. Agric. Res. 18: 119-125. PI. 1-2. 1919.— Pot cultures were used. The 



