December 15, 1922] 



SCIENCE 



695 



producing scab of potatoes and scurf of sweet 

 potatoes, may be largely if not entirely sup- 

 pressed. The transformation of sodium car- 

 bonate, present in excessive amounts in so-called 

 black alkali soils, into sodium sulfate may be 

 similarly accomplished. The direct use of inocu- 

 lated sulfur for the purpose of supplying sulfates 

 where these may be present in inadequate 

 amounts, or the use of the same material for the 

 production of potassium sulfate from greensand 

 marl is indicated. The elimination of soil-infest- 

 ing insects, or nematodes and of undesirable vege- 

 tation may also be accomplished by means of 

 sulfur inoculated -with cultures of Thiol) acillus 

 thioxidans. 



Trend of modern fertilizer plant construction: 

 Peter S. Gilchkist. This paper will deal with the 

 construction features of up-to-date fertilizer plants, 

 including types of buildings, materials for build- 

 ing construction, equipment for plants and the 

 relation of equipment to the building. Especial 

 attention will be given to the design of plants 

 with the necessary equipment for the economical 

 handling of materials, silos or storage bins for 

 storing phosphate rock, air separation for ground 

 rock, the development of mechanical dens for 

 making acid phosphate and economical methods 

 of manipulating and bagging finished goods. 



Modern trend in fertiliser plant operation: 

 E. H. Armstrong. The manufacture of sulfuric 

 acid as the basis of the fertilizer industry. A 

 brief resume of this subject, giving developments 

 from its inception to the present time. A brief 

 discussion of the present methods pursued in 

 operating a modern sulfuric acid plant. A short 

 discussion of the developments in acid phosphate 

 manufacture, together with a review of the more 

 modern methods and the trend toward finer grind- 

 ing, emphasizing the necessity for close chemical 

 control. A comparison of the old and new ways 

 of mixing fertilizer, showing the tendency towards 

 larger mixing .units and a better conception of 

 the necessity for more methodical sampling and 

 for coordination between operating and analytical 

 departments to insure closer analyses. 



Modern trend of eiiemical control in the fer- 

 tilizer industry: H. 0. Mooee. Chemical control 

 involves the practical application of chemical 

 phenomena and laws to the manufacturing opera- 

 tion, thereby directing or restraining influences 

 as conditions require. Chemical control is not 

 chemical analyses alone, but is the sum total of 

 chemical analyses, chemical knowledge and prac- 

 tical experience and the correlation and applica- 



tion of these with the problems at hand. Chem- 

 ical control has pointed the way to remarkable 

 economy in the manufacture of sulfuric acid; to 

 economic progress and a greatly improved product 

 in the manufacture of acid phosphate; and to 

 the cost, mechanical condition and quality in the 

 manufacture of mixed fertilizers. The modern 

 trend of chemical control in the fertilizer indus- 

 try is to substitute knowing for guessing ; to 

 learn the best working conditions for each type 

 of plant, and the materials and mixtures it is 

 required to use or make ; to determine the best 

 and most economical combinations of materials to 

 be used in the manufacture of fertilizer; to deter- 

 mine the best methods of formulating and using 

 the materials so selected ; to determine the gen- 

 eral crop needs and materials most suitable for 

 supplying it; to determine the combination of 

 materials which must be avoided or if possible to 

 see how this maj^ best be done; to determine the 

 best means of avoiding large unit losses of mate- 

 rials, of preventing analytical discrepancies and 

 of sampling all products to insure reliable 

 analytical results. Thus chemical control prop- 

 erly becomes both the governor and safety valve 

 on the whole machinerj' of the fertilizer industry. 

 Modern trend in state fertilizer control: An- 

 drew J. Patten. 



Modern trend in fertilizer legislation: J. E. 

 Breckbnkidge. 



Modern trend in fertilizer experimentation: 

 Dr. H. J. Wheeler. Fertilizer ex;periments at 

 Bothamsted on permanent meadows, at Rhode 

 Island on limed and nnlimed soils and with dif- 

 ferent phosphates and potash salts, coupled with 

 similar experience elsewhere, and the studies of 

 lime-magnesia ratios, of the different effects of 

 iron, magnesia and of manganese, boron, stron- 

 tium, barium, lithium and other elements not usu- 

 ally considered plant foods have shown the ne- 

 cessity for intensive study of the physical, chem- 

 ical and biological conditions best adapted to each 

 kind of plant. At the same time, the relation of 

 soil colloids to problems of fertilization and plant 

 nutrition has been especially emphasized. Future 

 investigators will study thoroughly physical and 

 biological soil properties as related to fertiliza- 

 tion, correlating them more closely than before 

 with individual plant requirements and a,dapta- 

 tions. 



The determination of potash in mixed fertili- 

 zers: P. B. Carpenter. A brief review of the 

 methods for the determination of potash in mixed 

 fertilizers prior to the adoption of the Lindo- 



