FERTILIZERS. 23 



to 714.04 llw. per aiTe) of Thomas .slajf resulted in an increased total yield of wheat, 

 potatoes, alfalfa, hay, and also an increase in total amount of nitrogenous matter. 



The natural phosphates and their use in agriculture, Maiziekes { U Engrain, 

 17 {190'2), No. l.i, pp. SOS, 304). — This article briefly reviews experiments with 

 untreated phosphates by various investigators on different kinds of soils. The author 

 considers the results inconclusive except as regards the favorable action of such phos- 

 phates on i>eaty soils and sandy plains. 



Slags and superphosphates — results of 10 years' experiments, E. C. Pradel 

 {Sta. jKjro)i. Xanci/, Bid. 4, l'->01, pj). 15-^4)- — The principal conclusion from these 

 experiments is that slags are preferable to superphosphates on all soils containing less 

 than 3 per cent of assimilable lime. 



The agricultural value of Martin slag, A. Petekmann {Jour. Agr. Prat., n. ser., 

 3 {1902), No. 17, pp. 535, 556').— This is a basic slag siinilar to Thomas slag. Analy- 

 ses of 4 samples reported in this article show percentages of i)hosphoric acid soluI)le 

 in mineral acids varying from 2.12 to 10.8; of free lime from 0.19 to 3.7; soluble silica 

 from 8.21 to 25.74. The solubility of the fine meal in Wagner's reagent varied from 

 76 to 100 per cent. In pot experiments with wheat using amounts of the two phos- 

 phates furnishing equal amounts of phosphoric acid the Martin slag was fully as 

 effective as Thomas slag. 



Discovery of mineral phosphates in South Australia {Jour. Agr. and Ind. 

 South AxiHtralia, 5 (1902), No. 8, j>j>. 670, 671). — This is an extract from a report by 

 H. Y. L. Brown to the minister of mines of South Australia announcing the dis- 

 covery of phosphate deposits on Northern Yorke's Peninsula. The investigations 

 made indicate " that the (luantity of rock containing a sufficient percentage of phos- 

 phate of lime to render it of commercial value is very large, and the configuration of 

 the country is most favorable to the opening of quarries, whereby the rock can be 

 raised cheaply and exjieditiously, and shipments averaging 70 per cent of tricalcic 

 phosphate and less than 6 per cent of iron and alumina could be easily selected." 



Note on free acid in superphosphate, J. Ostersetzer {Chem. News, 85 {1902), 

 No. 2213, pp. 195, 196). — A brief note on the appearance of intermediate tints between 

 oi^alescence and complete neutrality when titrating superphosphates with half-normal 

 or tenth-normal sodium hydroxid using various indicators. 



Buying and using commercial fertilizers, L. A. Clinton {New York Cornell 

 Sta. Bid. 201, 2>p. 179-J95, Jigs. G). — This liuUetin discusses methods of calculating 

 the commercial value of fertilizers and the economy of buying unmixed fertilizing 

 materials and mixing them on the farm, and reports the results of comparative 

 tests of acid phosphate (dissolved rock phosphate), basic slag, floats, and dissolved 

 boneblack oii clover, Canada field peas, rape, radishes, oats, barley, and parsnips 

 grown in boxes filled with quartz sand. The acid phosphate used contained 12.42 

 per cent of soluVjle phosphoric acid, 17.45 per cent available, and 18.36 i>er cent total 

 phosphoric acid. The corresponding percentages for the dissolved boneblack were 

 10.71, 14.61, and 16.25. The basic slag contained 15.94 per cent of total phosphoric 

 acid, thefloats 31.37 jier cent. The best returns were secured with acid phosphate 

 and dissolved boneblack in nearly every case. The two were about equally effective 

 on clover and peas. These crops were apparently able to make some use of the basic 

 slag, but the product was only about half of that secured with the soluble phosphates. 

 The untreated phosphate (floats) was apparently without effect on the clover and 

 peas. Rape made best growth with floats, radishes with acid phosphate, although 

 the yield of the latter was increased by the floats and basic slag. "The results 

 seem to show that the members of the Crucifera3 order are able to extract food from 

 the insoluble forms of phosphoric acid." The largest yields of oats and barley were 

 obtained with the soluble phosphates, the oats making a better growth with basic 



5301— No. 1—02 3 



