SOILS FERTILIZERS. 421 



the consumption of sodium nitrate, 1906 to 1911. inclusive, supplementing data 

 given in the article by E. K. Scott noted above. 



Potash salts a protection against frost, Maas (Illus. Landw. Ztg., 32 (1912), 

 Xo. 6, pp. 39, .'lO, figs. ^). — Marlied effects in preventing frost injury to rye and 

 potatoes by liberal applications of potash salts are reported. 



Potash, salts a protection against frost, W. Golte (IUus. Landw. 7Ag., 32 

 {1912), No. 10, p. 77; ahs. in Internat. Inst. Agr. [Rome], Bui. Bur. Agr. Intel, 

 and Plant Diseases, 3 (1912), No. >}, pp. 902, 903).— Liberal applications of pot- 

 ash salts apparently prevented frost injury to rye by increasing the concentra- 

 tion of the soil water and thus preventing the freezing of the soil and by with- 

 drawing a certain amount of water from the tissues of the plants. 



Fertilizer experiments with ground phonolite, W. Thaeb (Jour. Landw., 60 

 (1912), No. 1, pp. 19-30). — Comparative tests of 40 per cent potash salt and 

 phonolite on beans and potatoes showed neither appreciable direct action nor 

 after effect of the potash in the phonolite. 



Results of investigations of the potash deposits of Upper Alsace, B. 

 FoRSTEB {Mitt. Geol. Landesanst. Elsass-Lothr., 7 (1911), No. J/, pp. 3-^9-52-}, 

 pis. 7; ahs. in Kali, 6 (1912), No. 4, pp. 77-81; Internat. Inst. Agr. [Rome], 

 Bui. Bur. Agr. Intel, and Plant Diseases, 3 (1912), No. //, pp. 901, 902). — The 

 character of these deposits as determined by numerous deep borings is described. 

 It is estimated that they are capable of yielding 1,472,058,000 metric tons of 22 

 per cent i)0tash salts. 



The composition of the Pacific kelps, J. W. Tukrentine (Jour. Indus, and 

 Engin. Chem., 4 (1912), No. 6, pp. .'i31-Ii35). — In analyses of 81 samples of oven- 

 dried seaweeeds from the Pacific coast the potash (K2O) varied from 0.37 per 

 cent (equal to KCl 0.59 per cent) in the stipe of Pterygophora californica, to 

 29.9 per cent (equal to 47.5 per cent KCl) in bulbs of Pclagophyeus porra. 



" When the average potassium chlorid content of the 29 samples of the 

 northern kelps (from Puget Sound) is compared with that of the 27 samples of 

 the southern (from the region of San Diego), the respective values being 21.3 

 per cent and 23.4 per cent, it appears that the content of the southern plants 

 exceeds that of the northern." However, choosing the 4 varieties in the 

 northern collection which occur in the greatest quantities (the genuses 

 Nereocystis, Macrocystis, Postelsia, and Egregia — 9 specimens), the average 

 KCl content is 25.7 per cent, and the 2 genuses of the north considered as a 

 commercial source of potash, Nereocystis and Macrocystis, show an average 

 content for 6 specimens of 29.4 per cent. The average content of the 2 speci- 

 mens of Macrocystis from Puget Sound is 26.5 per cent ; that of the 22 specimens 

 from the south is 21.6 per cent. 



" The average iodin content of the 30 specimens from Puget Sound is 0.155 

 per cent and of the 4 main varieties (10 specimens) is 0.14 per cent. The 

 average of 6 specimens of the 2 giant kelps, the Nereocystis and the Macro- 

 cystis, is 0.16 per cent. The average percentage content of the southern kelps 

 is 0.29, a value nearly twice that from the northern kelps." 



Of the 3 giant kelps Nereocystis contained on the average 32.6 per cent 

 KCl, 0.14 per cent iodin; Macrocystis 22.2 per cent KCl, 0.27 per cent iodin; 

 and Pelagophycus 31.3 per cent KCl, 0.36 iier cent iodin. 



In addition to the variations in composition between the varieties of kelps 

 there was a marked variation between members of the same genus from different 

 localities and from the same locality. There is also a variation strikingly 

 shown in the case of Pelagophycus between the different parts of a single plant. 

 These differences have been pointed out by Balch. 



