BUREAU OF SOILS. 231 



the use of large quantities of platinum, and in existing circumstances 

 platinum is not only very costly but also difficult to obtain. The 

 possibility of oxidizing ammonia commercially by means of electro- 

 lytic cells was therefore taken up and studied actively throughout 

 the year. This work was also carried on in cooperation with the War 

 Department, which assigned chemists to work Avith the chemists of 

 the Bureau of Soils. The fact that ammonia could be oxidized in 

 this way with the production of ammonium nitrate as an end prod- 

 uct has been clearly demonstrated and the relative efficiency of the 

 process is being investigated. As a result of the work already done 

 the indications are that this process operated in connection with the 

 Haber process and thereby providing a market for the hydrogen 

 liberated in the oxidation process can be operated commercially in 

 competition with the Oswald method using platinum. 



Efforts were made during the year to encourage the largest cities 

 of the United States to utilize their garbage for the production of 

 grease and garbage tankage. The maj^ors of all the larger cities 

 not now possessing garbage-rendering apparatus were communicated 

 with and their attention was called to the urgent need of both grease 

 and fertilizer materials, with a request that they take steps at once to 

 effect this conservation of waste materials. As a result of this work 

 certain cities during the year have taken definite steps to install 

 garbage-rendering plants. 



With regard to phosphoric acid the research work of the division 

 has been restricted during the year to the investigation of the pos- 

 sibility of smelting phosphate rock by some other means than electric 

 power. Furnaces of different types have been designed and con- 

 structed, with the result that it is now believed a furnace has been 

 found in which the smelting of the rock is satisfactory, with the 

 evolution of phosphorus fumes. This furnace is now being tested. If 

 satisfactory results can be achieved in this direction it will be possible 

 not only to produce double acid phosphate more cheaply than hereto- 

 fore, but what is probably of even more importance, it will be possible 

 also to use mine-run material from the phosphate mines and thus 

 avoid the heavy waste of phosphoric acid involved in the present 

 methods of washing and screening the rock. The regular annual sur- 

 vey of the phosphate industry was also made and published. 



The Avork of analyzing the raAv materials and slags from the blast 

 furnace industry, to determine if possible the amount of potash now 

 volatilized and lost in that industry which might be collected for fer- 

 tilizer, has been continued during the year. It is anticipated that 

 this Avork, wdiich invoh^es a A-ery large number of potash analyses, 

 will be completed during the current fiscal year. It is evident from 

 the work so far done that the amount of potash available from this 

 source, if suitable collecting apparatus were installed at the blast 

 furnaces, would be very large. Research work on several of the 

 problems involved in the commercial collection of potash from cement 

 kilns has been carried on in cooperation with several of the cement 

 companies of the United States, and the results of this investigation 

 have either been published or are now in press. 



The bureau's experimental plant for the study of the commercial 

 utilization of kelp as a source of potash has been in partial operation 

 during most of the fiscal year. Large amounts of kelp have been har- 



