SOILS FERTILIZERS. 533 



uiidor ;i constnnt prossiiiv of <U ft. Tlie vohinic aiid tinu' of How of cacli pcr- 

 colatt' was iiioasnivd, its electrical coiKhictivity was tal<cii. and its cliciiiical 

 coiiipositioii was dt^eniiiiicd. 



The ('(nicliisions reached from tiie results obtained were as follows: 



"(1) Neutral salts such as the chlorlds in the i)resenee of carbonates can be 

 couii)arativel.v readily and completely leached from the soil. 



"(2) With continued leachinp of soils containing; 'black alUali ' there is an 

 increase in the rate at which ])ercolation takes place, due ])robably to the reduc- 

 tion of the amount of alkali ])reseut and its effect on the physical structure of the 

 soil. 



"(,'^) With continued leacliiuf; there is a comparatively rapid reduction of 

 normal carbonates in the soil water, due in larj^'e measure to conversion into 

 bicarbonates. 



"(4) Bicarbonates are rapidly removed at first and then continue to l)e slowly 

 removed in the soil water in very small amounts, diminishing; so slowly as to be 

 practically constant for an indefinite period. 



"(5) Soils containiiifT ' black alkali ' can be reclaimed by leaching, but the time 

 and the amount of water re(iuired are probably much greater than in the case 

 of ' white alkali.' " 



The decrease of soil temperature with elevation in the Prologh Mountains 

 in Dalmatia, F. von Kerner (Met. Zt.^chr., 23 {1906), Xo. 9, pp. .',2J. i?,?).— 

 decreases of from 0.38 to 0.75° for each 300-meter increase in elevation were 

 observed. 



Notes on carbon bisulphid, its action on the lower plant organisms as 

 well as the fertility of soils, P.. IIeinze (Centhl. Bald. Irfc], ,?. AM., 16 

 (1900), .Yo. 10-13. pp. 329-35S; abs. in Chem. Centhl., 1906, II, No. 8, p. 699).— 

 Previous investigations on this subject are reviewed and experiments l)y the 

 author are reported which indicate that the beneficial effects observed in the 

 case of applications of carbon bisulphid to the soil may be in a measure obtained 

 liy green manuring with mustard, which supplies to the soil certain sulfur 

 carbon derivatives which have a similar action to carbon bisulphid in promoting 

 the activity of nitrogen-fi.xing organisms. A bibliography of 24 references to the 

 literature of the siibject is appended. 



The utility of earthworms in agriculture, E. de Ribaucourt and A. CoM- 

 liAULT (Abs. in Rer. Gen. Afjron., n. ser., 1 {1906), No. 9, pp. 37.'/-.38// ) .— This 

 is a review of observations and investigations showing the important part which 

 earthworms (Lumbricus) play in improving the chemical and physical i)rop- 

 erties of soils. 



Some contributions to the microbiology of soils, B. IIeinze {Ccntbl. Bait, 

 [rfc], 2. Aht.. IC, (1906), Nos. 20-21, pp. 6 ',0-653 ; 22-23. pp. 703-711: ahs. if 

 Chem.' CentbJ., 1906, II, No. 10, p. 903; Jour. Chem. 8oc. [London], 90 {1906), 

 No. .527. IT. pp. 625, 626). — The literature of the fixation of the free nitrogen 

 of the air Iiy lower organisms and the assimilation of free nitrogen by algse is 

 reviewed. 



The author's exjieriments indicate that in general pure cultures of the algjie did 

 not fix nitrogen in large amounts, although there was rapid fixation when the 

 cultures of the algiip were inoculated with Azotobacter or other nitrogen-fixing 

 organisms. The author concludes in general that the importance of algff> in 

 relation to nitrogen fixation of the soil depends mainly upon the fact that they 

 furnish a valuable and readily available supply of carbon compounds for the 

 assimilation of the nitrogen-fixing organisms, especially Azotobacter. 



Conditions affecting legume inoculation, K. F. Kellerman and T. R. Robin- 

 son (U. ,S'. Drpt. Apr.. Bur. Plant Indus. Bui. 100, pt. 8, pp. 15, pis. 2).— The 

 Iiulletin records the results of greenhouse studies on soils from different 



