728 EXPEEIMENT STATION RECORD. [Vol. 38 



but that the salt undergoes a double decomposition, part of the potassium 

 being retained by the soil. When the solution filters through the soil it 

 turns greenish. This is due to the transformation of the ferrocyanid into 

 ferricyanid. This oxidation appears to be due to some surface action, as 

 it also occurs when the solution is filtered through fine sand. Experiments 

 with potassium ferrocyanid did not give good results as, even in dilute solu- 

 tions, the salt has a harmful action on vegetation." 



Manurial experiments with mang'anese slag, M. Popp (Fiihling's Landw. 

 Zty., 65 {1916), No. 15-16, pp. 354-360; abs. in Interna t. Inst. A(jr. [Rome^, 

 Internat. Rev. Sei. and Pract. Agr., 7 {1916), No. 11, pp. 1600, 1601; ahs. in 

 Jour. Soc. Chem. Indus., S6 {1917), No. 16, p. 933). —It is stated that " the manu- 

 facture of ferromauganese and spiegeleiseu in Germany yields as by-product 

 large quantities of manganese slag, of which the average composition is 24.4 

 per cent Mn., 30.5 per cent SiOj, 9.S per cent AI.O3, 33.4 per cent CaO, 6.3 per 

 cent MgO, 1.2 per cent sulphur, and traces of iron. The manganese is insolu- 

 ble in water but slowly soluble in weak acids. 



"A series of pot experiments were carried out to compare its manurial 

 value with that of anhydrous manganese sulphate. White Petkus oats were 

 sown in pots each containing 10 kg. of sandy soil (with 0.28 per cent CaO, 

 0.14 per cent P2O5, 0.13 per cent KjO, and 0.15 per cent nitrogen), which re- 

 ceived further 1.5 gm. of potash, 1 gm. of phosphoric acid, 1.5 gm. of nitrogen, 

 and 60 gm. of calcium carbonate in the form of marl, besides dressings rang- 

 ing from 0.5 to 10 gm. of manganese either as finely powdered slag or as 

 sulphate. The manganese slag increased the yield of both grain and straw, 

 and the increase was greater the larger the amount applied, except for the 

 maximum dressing (10 gm.). In small amounts (0.5 and 1 gm.) the sulphate 

 was more effective than the slag, but with the larger dressings (2.5 and 5 

 gm.) the reverse was the case. With manganese slag the yield of grain was 

 affected more than that of straw, while the sulphate affected the yield of 

 straw most" 



AGRICULTURAL BOTANY. 



A textbook of botany for colleges, W. F. Ganong {New York: The Mac- 

 millan Co., 1917, pp. XIII-J-6O4, figs. ^02). — This edition is practically the same 

 as the volume previously noted (E. S. R., 36, p. 429), with the addition of 

 chapters on the genetic and ecological classification of plants. 



Plant physiology, V. I. Palladin, edited by B. E. Livingston {PhiladelpJiia: 

 P. Blakiston's Son £ Co., 1918, English ed., pp. XXV+320, figs. i7'3).— This is 

 an authorized English edition based on the German translation of the sixth 

 Russian edition and on the seventh Russian edition published in 1914. The 

 book is specially designed for students and is noteworthy for its brevity and 

 conciseness. The subject matter is largely treated from the standpoint of 

 physiological chemisty as applied to plant life, the chemical aspects of plant 

 physiology receiving special emphasis. The editor, by means of copious notes, 

 has added much pertinent material, thus completing the presentation of the 

 subject. The part of the work devoted to the physiology of nutrition is much 

 more extended than that treating of growth, configuration, and reproduction, 

 but a classified list of books makes available references to additional infor- 

 mation. 



[Studies in plant nutrition], P. L. Gile and J. O. Carbeko {Porto Rico Sta. 

 Rpt. 1916, pp. 13-17). — Summary reports are given of investigations on lime- 

 induced chlorosis, immobility of iron in the plant, the assimilation of iron by 

 rice from certain nutrient solutions, and the absorption of nutrients as affected 



