124 EXPERIMENT STATION RECOED. [Vol.38 



" If it be assumed, further, that the dust escaping from the kilns amounts on 

 an average to 4 per cent of the raw mix fed into the kilns in the case of dry- 

 process plants, and to 2 per cent for plants using the wet process, then, on the 

 basis of the results already given, the total potash content of the dust escaping 

 from the former plants will vary in different plants from 1.4 to 20 per cent, and 

 in the latter from 9.1 to 35.1 per cent. 



" The ratio of potash to soda in the dust as determined for 20 different plants 

 varies from 0.92 to 6.07, with an average of 2.66." 



The recovery of water-soluble potash as a by-product in the cement in- 

 dustry, W. H. Ross and A. R. Merz (Amer. Pert., 47 {1917), No. 7, pp. 26-28).— 

 This article is based on the investigations noted above. 



The nature of cement mill potash, R. J. Nestell and E. Anderson {Jour. 

 Indus, and Engin. Chem., 9 {1917), No. 7, pp. 646-651, fig. i).— Studies of the 

 potash content of cement mill dust and fumes are reported. It was found that 

 dust from cement kiln gases may be composed of mechanically carried-over raw 

 material and solid residues from fuel combustion, together with volatilized 

 alkalis. 



" Such dust contains considerable amount? of potash present both in readily 

 and slowly soluble form. The readily soluble potash usually occurs as sulphate, 

 due to a combination of this base with the sulphur of the fuel and, where there 

 is a deficiency of sulphur, partly as carbonate. The slowly soluble potash is 

 probably of a siliceous nature, largely formed by the union of potash vapor 

 with incandescent a.sh particles. This siliceous potash becomes soluble on 

 boiling with water for a few hours, and on treatment with cold water for 

 longer periods. The presence of lime accelerates the solution. Slowly soluble 

 potash compounds are also formed by the interaction of potash salts in solution 

 with siliceous material, this recombination being greatly accelerated by heat. 

 The action of moist soil promotes the availability of the slowly soluble potash. 

 In view of the gradual and continued solution of the potash in cement kiln dust, 

 it should be of particular value as fertilizer material." 



Recovery of potash from beet and cane molasses in the United States, 

 J. S. HoBN {La. Planter, 59 {1917), No. 8, pp. 122, i2S).— Reviewing the subject 

 from the practical standpoint the author concludes that the recovery of potash 

 15 very profitable in all distilleries at present, especially on large plantations 

 where the alcohol can be used for motive power in tractors and in beet produc- 

 ing regions far from a potash supply. It is further thought that the process will 

 always be profitable in the Hawaiian Islands and Australia for economic reasons. 



Comparative fertilizing values of ground limestone and dolomitic lime- 

 stone, H. VON Feilitzen {Svenslca Mosskulturfor. Tidskr., 30 {1916), No. 4. PP- 

 S83-S92, figs. 2). — Experiments comparing pure ground limestone with dolomitic 

 limestone containing 55.09 per cent calcium carbonate and 41.66 per cent mag- 

 nesium carbonate showed that the dolomite when well pulverizdd can be used 

 with good results on soil poor in lime. 



Lime on the farm, F. B. Gutheie {Dept. Agr. N. S. Wales, Farmers' Bui. 

 115 {1917), pp. 31). — This is a discussion of different forms of lime and their 

 profitable utilization in agriculture, with special reference to New South Wales . 

 conditions. 



Law in relation to commercial fertilizers {Bui. Bd. Agr. Del., 6 {1917), No. 

 4, pp. 3-10). — The text of the Delaware fertilizer law is given, together with a 

 copy of the rules and regulations to carry it into effect. 



Commercial fertilizers, H. E. Curtis et al. {Kentucky Sta. Bui. 205 {1916), 

 pp. 397-538). — This is the fertilizer inspection and analyses report for Ken- 

 tucky for 1916. 



