718 EXPEKIMENT .STATION KECOKD. 



24, y(>, jind 72 in. during; 101.'} is hIwj given. Tlie growing season of 191o was 

 somewliat longer, tlie itrec-ipitatlon greater, and the %\-ind velocity less tlian 

 normal. 



Tlie first killing frost occurred September 17, wliich is later than usual. A 

 summer frost occurred the night of July 31. The highest temperature was 89° 

 I'\, July C; the lowest, — 30°, January 7. The total precipitation was 13.01 in., 

 as compared with a 20-year average of 10.21 in. The lowest relative humidity 

 was 15 per cent. July 2. The greatest velwity of wind was 60 miles per hour. 

 Juno 11. 



Salient features in the geological history of Australia, with special ref- 

 erence to chang'es of climate, W. G. Wooi.noi'oii {Off. Yearbook A«v/., 7 

 (1901-1913), pp. 56-58). — The evidences of climatic variations during the 

 different geological ages in Australia are briofiy summarize*!. 



SOILS— FERTILIZERS. 



The present status of soil chemistry, with particular reference to organic 

 compounds, H. I^. Jodiui (Laiidir. ^'e)•f<. stdt.. So (JHUf), No. S-Jf. pp. S.')9-391}. — 

 This article is based mainly on investigations conducted l)y the author at the 

 Iowa and Michigan experiment stations (E. S. K., 22, p. 61S; 25, p. 622; 26, 

 pp. 320, 615, 616; 28, p. 813; 29, pp. 124, 316, 723; 30, p. 122). 



The topics discussed are the sulphur compounds of the soil, the influence of 

 meteorological and biological factors on the soil nitrogen, the older and the 

 more recent theories regarding the nature of humus and its behavior with cer- 

 tain reagents, genetic relations between the chemical compoimds in soil and 

 those in plants and animals, the nature of nitrogen comiKjunds in the soil, the 

 organic nitrogen compounds of the soil, the separation of the nitrogen com- 

 pounds in sulphuric-acid extracts of the soil, cleavage products of nucleo-pro- 

 teins, lecithin products in the soil, pyridin derivatives in the soil, the ammoni- 

 fication of amino-acids and acid amids In the soil, the occurrence of carbon 

 dioxid, alcohols, and aldehydes in the soil, and soil organic acids. 



A list of 71 references to literature bearing on the subject is appended. 



On the orig'in of the loess of southwestern Indiana, E. W. Shaw {Science, 

 n. ser., J^l {1915), No. lO.'fG, pp. lO'f-lOS). — The author concludes from a study 

 of the loess areas of the United States " that the so-called marl loess of south- 

 western Indiana consists of wind-deposited true loess, stream-laid valley filling, 

 and dune sand, and that the true loess part of it. together with the ' common 

 loess,' corresponds to the well-known loess of other parts of the Mississippi 

 basin." 



Composition and origin of different horizons of some South Russian soils 

 and subsoils, A. I. Xauokikii {iiclsk. Khoz. i Lu'Hor.. 2.n {1911), Nov.. pp. 

 367-379; 238 {1912), Jan.. pp. 3-17; Mar., pp. 399-JilJt; .i39 {1912). May. pp. 

 3-14; June, pp. 159-180, fig. 1; July, pp. 289-305; «/>.s. in Zhiir. Opytn. A(/ron. 

 {Ruvs. Jour. Expt. Landw.), IJ, {1913), No. 4. pp. 3. '(2-.] -',7). —The author deals 

 mainly with the varying humus content of the soils as determined by the 

 pemianganate method. 



A so-called isohnmic zone of forest soils containing from 1 to 2 per cent of 

 humus embraces the Governments of Kiev and Yolynsk. The adjoining border- 

 land of loess iX)dzol clays contain not less than 2 jier cent, often more than 3 

 per cent of humus. The soils intermediate between forests and steppes vary in 

 humus content from that of the forest soils on the north to that of the cher- 

 nozem steppes of the south. The stepjies soils are divided into (1) those of 

 the north covered with typical chernozem with 5 to 9 per cent of huiiius; (2) 

 the brown soils of the coast steppes containing not more than 3 per <-eat of 



