818 EXPERIMEjSTT SIATION record. [Vol.38 



total surface area, the total quantity of phosphorites contained in the beds, 

 and the corresponding total quantity of phosphoric anhydrid, were estimated. 

 The phosphorites were divided into three groups, containing, respectively, from 

 12 to 18, from 18 to 24, and more than 24 per cent of phosphoric anhydrid. 

 Among the phosphorites studied in 1914 those of group 2 were found in 13 out 

 of 17 of the beds examined and usually coutai&ed 20 per cent of phosphoric 

 anhydrid. The phosphorites of the other four beds belonged to group 1. 



The districts examined in 1914 contained a total surface area of beds of 

 1,730 square miles, a total quantity of phosphorites of 1,730,000,000 tons, and 

 a total quantity of phosphoric anhydrid of 283,000,000 tons. The average pro- 

 duction was 7 cwt. per 10 square miles. 



If the quantity of phosphorites estimated in the beds in 1914 be added to 

 that of preceding years, a total of 5,020,000,000 tons is obtained, of which 

 68.1 per cent is in group 1, 29.2 per cent in group 2, and about 2 per cent in 

 group 3. 



The report ends with a study by SamoOov of the pliosphorite beds of the 

 right bank ©f the river Desna (Krolevets district, Chernigov Province). These 

 beds on account of their origin, their form, the large accumulation of phos- 

 phoric nodules of various types, and the nature of the cementing body, possess 

 particular scientific interest from a geological and raineralogical point of view. 



Influence of carbonates of magnesium and calcium on bacteria of certain 

 Wisconsin soils, H. L. Fut.mee {U. S. Dept. Agr., Jour. Ayr. Research, 12 

 {WIS), No. 8, pp. Jt6S-50Ji, figs. 11). — Investigations at the Wisconsin Experi- 

 ment Station are reported in which the effect of magnesium and calcium car- 

 bonates, limestone, monocalcium phosphate, and dibasic magnesium phosphate 

 (and in certain cases calcium and magnesium chlorids) on the number and 

 activity (ammonia and nitrate formation and nitrogen fixation) of bacteria 

 was studied with pure cultures and with the ordinary flora in acid Colby silt 

 loam soil, acid Plainfield sand, and neutral Miami silt loam. " The calcium 

 carbonate, magnesium carbonate, and limestone were added in amounts suf- 

 ficient to satisfy one-fourth, one-half, and full calcimn-carbonate requirement — 

 that is, to neutralize one-fourth, one-half, and the total active acidity." The 

 phosphates were added in varying amounts. 



It was found that the number of bacteria in the acid silt loam and acid 

 sand was increased by the applications of calcium carbonate, magnesium car- 

 bonate, or limestone, magnesium carbonate increasing the number to a much 

 greater extent than either calcium carbonate or limestone. Monocalcium 

 phosphate and dibasic magnesium phosphate slightly increased the number of 

 bacteria in neutral soil. 



Nitrification was promoted by adding limestone, calcium carbonate, or mag- 

 nesium carbonate. In soils to which no nitrogenous matter had been added, 

 magnesium carbonate favored nitrate accumulation more than either calcium 

 carbonate or limestone. The phosphates increased the accumulation of nitrate 

 nitrogen to a very small extent. When gelatin was added to the soil, mag- 

 nesium carbonate did not increase nitrification any more than calcium car- 

 bonate or limestone. The three carbonates increased ammonification of blood 

 meal by pure cultures of Bacillus tumescens and B. subtilis in sterile acid silt 

 loam soil. 



A culture of B. azotobacter failed to show an increase in total nitrogen in the 

 acid sand treated with carbonates and mannit and only a slight gain in acid silt 

 loam soil so treated. Pure cultures of B. radicicola, of both alfalfa and lupine 

 strains, and B. azotobacter were greatly benefited when inoculated into the 

 sterile acid silt loam soil previously treated with magnesium carbonate or 

 calcium carbonate. Limestone barely increased the number of B. azotobacter 



