KEPORT OF THE SECRETARY. 109 



Among the various sources of nitrogen fertilizers, possible depos- 

 its of nitrates in the arid and semiarid areas of the country have 

 long held a prominent place in the scientific and popular mind. Our 

 people have observed and studied some deposits of this character. 

 Generally, however, these deposits are either too small in amount to 

 justify commercial exploitation or they are inaccessible to transpor- 

 tation or available water for working them, or are otherwise of 

 doubtful economic importance. There is no available experience in 

 this country to guide our people in working such deposits, the con- 

 ditions surrounding them being essentially different from those in 

 other countries. 



"Whether or not natural deposits of nitrates can be commercially 

 exploited is yet an open question, but it is a distinct advance to know 

 that such deposits exist. Various other sources of nitrogenous fer- 

 tilizers have also been investigated, and it is especially worth noting 

 that there is a well-defined tendency in our main coking regions to 

 introduce modern ovens and make available large quantities of am- 

 monia, which have generally been discarded until very recently. 



Especial interest attaches to the work on potash fertilizers, because 

 commercial sources of potash have been unknown in this country, the 

 world's supply in fact coming from the Stassfurt deposits in Ger- 

 many. The advantage of having a domestic source is so obvious as 

 to require no comment. Possible sources of potash are by no means 

 few. Much potash can be recovered from the immense accumulations 

 of sawdust in our lumbering regions, from the vinasses in our sugar 

 mills, from wool washings, etc. Possible sources of potash include 

 also the bitterns or mother liquors from our salt workings. These 

 are now under investigation. Segregated deposits of potash salts 

 may lie under our known salt deposits, or below the present surface 

 in desiccated sea or lake beds. This is now being investigated. The 

 desert basins are being explored by our agents for surface deposits 

 of potash, as well as nitrates. 



The utilization of natural potash-bearing silicates has long at- 

 tracted investigators and inventors. Vast deposits of potash feld- 

 spars, glauconite, leucite, and other suitable minerals exist in this 

 country, and our laboratories as well as private parties are now 

 actively at work on methods for extracting the potash. The extrac- 

 tion of potash in various ways is perfectly feasible in the laboratory. 

 But the energy required to break down the chemical combinations 

 and extract the potassium is so large as to make its production in- 

 hibitive at the present time. Extremely cheap power or the inci- 

 dental production of valuable by-products might possibly make the 

 jDotash silicates commercially available. 



