378 SOILS. 



New Mexico. Few analyses of New Mexico soils have been 

 made, but the average results of six partial determinations 

 made by Goss, and one full analysis made by Hare according 

 to the method of the writer, and given below, show substantial 

 accord with the averages of the above table. The averages of 

 Goss' determinations are : Potash .780, Phosphoric acid 

 .221, Nitrogen .108 per cent. 



CHEMICAL ANALYSIS OF RIO GRANDE SILT (by Prof. R. F. Hare.) 



Deposited on on land by irrigation. 



Insoluble matter 63.70 



PotashiKaO) 1.06 



Soda NsaO) 22 



Lime (CaO) 4.97 



Magnesia ( MgO) 2.43 



Br. ox. of Manganese (MnsO 4 ) .14 



Peroxid of Iron (Fe a O s ) 5.80 



Alumina (AlaOj) 6.86 



Phosphoric acid (P S O 5 ) 16 



Sulfuric acid (SO 3 ). 13 



Carbonic acid (CO a ) 7.45 



Water and organic matter 9.98 



Humus 1.17 



Nitrogen 1 1 .1 1 



per cent, in soil .13 



Hygroscopic Moisture 2.63 



absorbed at ..C ... 



DISCUSSION OF THE TABLE. 



Lime. Considering in this table, first, lime, a glance at the 

 columns for the two regions shows a surprising and evidently 

 intrinsic and material difference, approximating in the average 

 by totals to the proportion of i to 1 1 ; in the average by states, 

 i to 14 1/2. This difference is so great that no accidental errors 

 in the selection or analysis of the soils can to any material de- 

 gree weaken the overwhelming proof of the correctness of the 

 inference drawn upon theoretical grounds, viz., that the soils of 

 the arid regions must be richer in lime than those of the humid 

 countries. For the differences in derivation would, in view of 

 the wide prevalence of limestone formations in the humid 

 regions concerned, produce exactly the reverse condition of 

 things from that which is actually found to exist; and if fur- 

 ther proof were needed it can readily be found in the detailed 

 discussion of the analyses of the soils of the arid areas forming 



