864 



SCIENCE 



[N. S. Vol. XLIV. No. 1146 



NITRATE DEPOSITS IN THE UNITED 

 STATES 



A press bulletin of the U. S. Geological Sur- 

 vey states that nitrate deposits in many parts 

 of the United States have been examined dur- 

 ing the last two years by the survey. The im- 

 portance of finding a natural supply of ni- 

 trates within our own borders has given 

 incentive to this work and has directed wide- 

 spread public attention to the subject. 



Prospectors in many places have raised great 

 hopes by finding good surface showings of 

 these salts, but investigation has seemed to 

 force the acceptance of a general adverse judg- 

 ment as to their value — a judgment that has 

 been adopted with the greatest reluctance by 

 all concerned. Incidentally, advantage seems 

 to have been taken of the situation to promote 

 certain stock-selling enterprises, even after the 

 evidence as to the worthlessness of the deposits 

 became sufficient to satisfy any competent 

 judge, so that one is forced to question either 

 the good faith of the promoters or their prac- 

 tical judgment. 



As a result of careful study of these depos- 

 its, and particularly of evidence gathered on 

 recent visits to prospects in different parts of 

 the country, Mr. Hoyt S. Gale, a geologist of 

 the Federal Survey, has submitted the follow- 

 ing general summary, which is commended to 

 the consideration of those who are tempted to 

 invest their money in such enterprises. 



Fine specimens of practically pure nitrate 

 of soda and nitrate of potash (saltpeter) have 

 been found in many parts of the country, and 

 careful investigation of specimens and locali- 

 ties seems to warrant some definite conclusions 

 as to the practical value of these deposits, espe- 

 cially to those who are invited to spend their 

 money in investigations like those the survey 

 has already made. 



The nitrate salts occur as crusts or films on 

 the faces of ledges; as seams — most of them 

 thin, though some are fairly thick — in crevices 

 of shattered rock ; and as deposits filling spaces 

 in porous rocks at and near the surface or ex- 

 tending to a depth of several feet. They are 

 naturally preserved in recesses in the rock 

 ledges, where they are sheltered from the dis- 

 solving action of rain, snow water, or even 



mist. They are found in lava ledges, in beds 

 of volcanic tuff or ash, and in limestone and 

 sandstone. Their existence or preservation is 

 apparently dependent rather on the shattered 

 or porous nature of the rock than on its kind 

 or composition. These deposits, which have 

 been referred to as cave or ledge deposits, are 

 of essentially the same type wherever found, 

 although they vary considerably in details of 

 occurrence. 



The incrustations are found not only on the 

 faces and fractures of ledges of solid rock, but 

 some of them form layers or cementing con- 

 stituents in the loose soil and rock breccia at 

 the bases of cliffs, or lie in places protected 

 from the weather. Some samples obtained 

 from both these sources are rich in nitrate 

 salts, and analyses of such materials will bear 

 little significant relation to the actual char- 

 acter or content of the mass of the rock of 

 which the ledge is formed. It appears that 

 the deposits are surficial — that is, they do not 

 extend far into the mass of the rock — and the 

 nitrate salt found is insignificant in amount. 



Nitrates are found in unusually large quan- 

 tities in some soils and in some clay hills, par- 

 ticularly in southern California. These de- 

 posits have been examined by many persons 

 and the general conclusion reached has been 

 unfavorable to the idea of their practical utili- 

 zation. The nitrate content, although un- 

 usually large as compared with the content of 

 ordinary soils, probably does not average over 

 1 or 2 per cent, of the soil or clay, and it is 

 very doubtful whether the material could be 

 worked commercially. 



Any one who is not convinced by the judg- 

 ment already reached as to these deposits and 

 who is determined to devote his time or money 

 to their further exploration should do so with 

 full knowledge of the evidence already in hand 

 and should not be led into such a venture by 

 more or less misleading representations. The 

 Geological Survey will always be glad to make 

 an examination of any samples submitted. 



AGRICULTURE OF THE HIDATSA 

 INDIANS 



A doctor's thesis of unusual practical value 

 is that of Dr. Gilbert L. Wilson submitted in 



