SOILS — FERTILIZERS. 623 



80.1; with oats ammonium sulpliate averaged in eight cases 132.5 and lime 

 nitrogen in nine cases 82 ; and with potatoes ammonium sulphate was 85 in one 

 case and lime nitrogen averaged 62.2 in four cases. 



The size of kelps on the Pacific coast of North America, T, C. Frye, G. B. 

 RiGG, and W. C. Ceandall {Bot. Gas., 60 (1915), No. 6, pp. 473-482, figs. 2).— 

 The results of observations, conducted as a part of the general investigation of 

 the fertilizer resources of the United States by the Bureau of Soils, are re- 

 ported which do not tend to confirm the earlier statements of the great length 

 of Nereocystis and Macrocystis, but do confirm those as to the length of Alaria 

 flstulosa. The maximum width of A. fistulosa was found to be more than 

 twice as great as has been previously reported by others. The longest Macro- 

 cystis plant found measured 45.7 meters (about 150 ft. ) , the longest Pelagophycus 

 porra 45 meters, the longest Nereocystis 20.7 meters, and the longest A. fistulosa 

 22 meters. The shortest Alaria, 13 meters long, measured 232 cm. (about 7.6 ft.) 

 in width, the greatest width observed. 



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



The composition of blast furnace gas dust (kali-asch), A. VIjetheim 

 {Verslag. Landbouwk. Onderzock. Rijkslandbouioproefstat. [Xelherlands], No. 

 IS, {1915), pp. 8^-90).— Analyses of three samples of the dust of settled blast 

 furnace gas from iron works (kali-asch) showed aqua regia a soluble potash con- 

 tents of 12, 12.5, and 20.2 per cent, and water solulile potash contents of 7.6 8.7, 

 and 17.1 per cent, respectively. It is stated that the potash content varies so 

 widely with the other constituents that an average percentage can not be deter- 

 mined. In one case the high percentage of chlorids present was thought to have 

 reduced the fertilizing value of the dust for certain crops. 



Relation of lime to production of nitrates and mineral nitrogen, F. M. 

 Scales {Science, n. ser., 42 {1915), No. 1079, p. 317). — Fractions and multiples 

 of the lime requirement of an acid soil, as determined by the Yeitch method and 

 by adding sufficient calcium carbonate to produce a neutral reaction to litmus, 

 were added to 100-gm. portions of the soil, which received in addition ammonium 

 sulphate in one case and alfalfa powder in the other. After moistening with 

 18 per cent of distilled water and incubating for three weeks at from 28 to 30° 

 C, "determinations of nitrate and mineral nitrogen present in the samples 

 showed that the nitrifying bacteria were most active in the presence of 50 per 

 cent of the calcium carbonate requirement and the ammonifying and nitrifying 

 groups combined in the presence of 75 per cent of the amount required according 

 to the chemical determinations. In this particular soil an excess of calcium 

 carbonate was markedly toxic for the nitrifying organisms and not stimulating 

 for the ammonifiers." 



Catalytes and their relation to crops, L. A. Musso {Rpt. Austral. A-:wc. 

 Adv. ScL, 14 {1913), pp. 667-671). — The author reviews and discusses briefly 

 the results of experimental work by others on the use of catalytic fertilizers. 



Influence of some manganese compounds containing oxygen on nitrifica- 

 tion, G. Leoncim {Stas. Sper. Agr. Ital., 47 {1914), No. 11-12, pp. 777-801).— 

 Experiments with lime, clay, and humus soils in compact and loose condition 

 to determine the influence of manganese dioxid and natural manganese hydrate 

 on nitrification when added in amounts as large as 6 per cent and as small as 

 from 0.035 to 2.2 per cent showed that both manganese compounds, and the 

 dioxid in particular, as a rule, retarded the nitrification of ammonium sulphate 

 in these soils and favored denitrification. In small percentages up to 0.184, 

 both compounds, the dioxid especially, aided nitrification, but beyond this concen- 

 tration nitrification was retarded. It is concluded that these compounds may 

 be used on such soils in concentrations not exceeding 0.184 per cent. 

 38859°— 16 3 



