159^ -MANURES AND MANURING 



the raw phosphate is ground, the size of the charge put into the mixer 

 and the duration of the mixing, the aeration of the reaction chamber. 

 With proper adjustment it is possible to convert the whole of the raw 

 phosphate into soluble phosphate and to obtain in the finished product 

 a very fine state of division. 



In a general way the temperature of the mixture is kept between 

 60° and 100° C. Outside these limits, which vary slightlj^ with the aci- 

 dity, a perceptible increase of the liquid phase is brought about which 

 exercises a marked influence not only on the state of subdivision of the 

 immediate product, but also on its successive transformation. This may 

 even confer definite hygroscopic properties to the mass and may CQmpletely 

 prevent the secondary formation of gypsum at the expense of anhydrite 

 which is a change conferring on the ultimate product a high degree of 

 dryness and fine subdivision. 



The experiments confirm the results of practical experience in manure 

 works, i. e. that in order to obtain a fine dry superphosphate the tempe- 

 rature in the mixer should not exceed lOooC. 



1166 - Substitutes for Basic Slag in Italy. — Menozzi a., in Le Stazioni spcrimcnlali af,raric 

 ilaliane, Vol. XlylX, No. i, pp. 7-9. Modena, 1916. 



Before the war, the annual consumption of basic slag in Itaty sur- 

 passed 30 000 tons, the greater part of which came from abroad. Since 

 August 1914, however, imports have almost ceased. Basic slag has 

 always been recommended in jjreference to superphosphate on soils poor 

 in iinie and rich in organic matter, but on many such soils superphosphate 

 has given excellent results. Pratolongo has recently shown b}^ his work 

 at the Milan Agricultural High School that such soils have a considerable 

 power of absorption for phosphoric acid in the form monocalcium phos- 

 phate, i. e. in the form present in superphosphate. He showed further: 

 i) that the phosphoric acid is very rapidly absorbed b}^ Itydrates of iron 

 and aluminion so that there is no chance of its being washed away; and 

 2) that superphosphate, though an acid manure, can be added to the soils 

 containing no lime without giving the soil an acid reaction. It is therefore 

 evident that applications of superphosphate on non-calcareous land are 

 not always followed by the ill-effects one might fear. 



It is only when dealing with bogs or sour peats that superphosphate is 

 really unsuitable and in these cases either bone meal may be used, or basic 

 superphosphate which has been on the Italian market for some time and 

 whose output could easily be increased should the demand for it arise. 



1 167 - Iodine Content of Stassfurt Salts. — Winkler l,. W. in ZeUschrift fur angewandte 

 Chemic, Year XXIX, No. 71, pp. 34.:-343. I^eipzis, September 5, igi6. 



Hitherto determinations of iodine in Stassfurt salts have given discor- 

 dant results. A series of very accurate analyses were therefore carried 

 out on carnallite and sylvine. The method employed is fully described. 

 Quantities of iodine found in the two minerals were as follows : 



