SOILS — FERTILIZERS. 815 



nn acid reaction toward litmus. . . . The amount of water-soluble ferrous iron 

 ... is extremely small, except where there is insufilcient aeration. ... In 

 general the aeration of Hawaiian soils is not sufficient for the best development 

 of beneficial bacteria. . . . The results of experiments indicate that the iron 

 and alumina present may partially take the place of lime in maintaining the 

 necessary neutral condition. On the other hand, experiments show that mag- 

 nesium carbonate seems to be distinctly detrimental to nitrification, while the 

 magnesia naturally present in the soils does not seem to interfere. . . . Ammo- 

 nification is more active in Hawaiian soils than nitrification, and investigations 

 show that aeration is not as essental to this process as it is to nitrification." 



Proper drainage, frequent deep plowing, and proper rotation of crops to 

 maintain the humus supply are considered to be essential in the proper man- 

 agement of the soils. The application of lime for the improvement of 

 heavy clays has been of doubtful effect. " With the exception of phosphoric 

 acid, all the mineral elements of plant food in Hawaiian soils are soluble in 

 water to a considerable extent, and if suitable physical conditions be main- 

 tained, and the humus content kept up, the need for mineral fertilizers will be 

 greatly reduced. The solubility of the mineral constituents can also be con- 

 siderably increased by soil heating." 



Tables of mechanical and chemical analyses of a large number of soils and 

 subsoils taken from different parts of all of the principal islands are also given. 



Van Bemmelen's method in the study of lateritic soils and the process of 

 laterization in Italian soils, A. de Dominicis (Staz. Sper. Agr. Ital., Jfl {191.'f), 

 Ko. 4, pp. 282-296; abs. in Chem. Abs., 9 {1915), No. 5, pp. 680, 6Si).— The work 

 of others bearing on the subject is briefly reviewed, and experiments with 

 soils from northern and southern Italy, using van Bemmelen's method for 

 studying lateritic soils, are reported, from which it is concluded that even 

 though van Bemmelen's method gives no quantitative results it does give infor- 

 mation regarding the nature of the soil colloids. Of the two classes of col- 

 loids, the first includes those soluble in hydrochloric acid in which the ratio 

 of alumina to silica is not less than 1 : 3, and the second class consists of 

 compounds of alumina and silica in the ratio of less than 1 : 3 and which are 

 soluble only in sulphuric acid. 



The results of these studies appear to be in accord with those of Barnardini 

 and Mazzone (E. S. R., 30, p. 320) with reference to the lateritic nature of the 

 soils of southern Italy. 



Soils, H. J. ViPOND (Union So. Africa Dept. Apr. Rpt. 1913-U, pp. 218-230, 

 pis. 10). — Chemical and mechanical analyses of various types of Transvaal soils 

 are reported and discussed. 



Chemical analyses of a number of soils and subsoils from the different forest 

 stations showed them to be of five classes, namely, soils with good percentages 

 of nitrogen, soils well supplied with lime, heavy soils, medium to sandy loams, 

 and sandy soils. There appeared to be a regular decrease in the percentages of 

 lime, magnesia, potash, and phosphoric acid soluble in strong hydrochloric 

 acid as the soils varied from heavy to light. There was, however, little differ- 

 ence between the heavy and light soils with reference to available phosphoric 

 acid and potash. "All five groups appear to contain adequate amounts of 

 available potash for cereal production, but very inadequate amounts of avail- 

 able phosphates," while the heavy soils, medium to sandy loams, and sandy 

 soils "also appear to be deficient in nitrogen and are certainly deficient In 



lime." 



Mechanical and chemical analyses of a number of soils belonging to six 

 typical groups, namely. (1) black turf soils, (2) red and brown heavy loams 

 or clay loams, (3) gray and brownish gray heavy loams to clay loams, (4) red 



