818 EXPERIMENT STATION RECORD. 



of small heavy grains of magnetite, leads to the conclusion that the loss has not 

 been alone by the removal by drainage of the constituents rendered soluble by oxi- 

 dation and other chemical changes, but largely by the removal of someof the lighter 

 argillaceousproducts by surface washing, and this view is upheld by the unexpectedly 

 heavy loss of silica. 



"In the case of the soils derived from the more basic lavas, augite andesite with 

 olivine and olivine basalt, nearly one-third of the silica has disappeared, the iron 

 oxids have increased by about one-twelfth, approximately one-sixth of the oxid of 

 manganese, four-fifths of the potash, and three-quarters of the phosphoric anhydrid 

 have been lost, while the amount of water and organic matter are approximately 

 four times the original quantity. The most striking losses have been in the lime, 

 magnesia, and soda, of Avhich, in round numbers, 96, 88, and 94 per cent have been 

 lost, respectively. The low increase in the proportions of the heavy iron minerals 

 tends to show that in the soils of this kind selected for comparison but little loss of 

 the lighter products of decomposition has taken place by surface washing. The 

 noteworthy point is the very high rates of loss of the lime, magnesia, and soda of 

 these basic rocks, probably in solution by drainage, showing that the feldspars, the 

 plentiful augite, and the olivine have suffered very complete decomposition during 

 their degradation." 



Analyses of 41 typical soils of the Island of Grenada are reported, 

 showing the mineral constituents soluble on digestion with 20 per cent 

 hydrochloric acid at the boiling point for 5 days, and the phosphoric 

 acid and potash soluble in 1 per cent citric acid on digestion for .""> days 

 in the cold. 



" [Of these 41 samples] 26 are deficient in phosphoric acid, in many cases the amount 

 present being very low, while in those in which phosphoric acid is present in fair 

 preportions it is as a rule in a state of very low availability, either on account of its 

 being in a very insoluble state in the form of apatite as it occurs in some of the 

 lavas, or from the low proportion it bears to the quantities of alumina and iron per- 

 oxid present. Potash is more or less deficient in 19 of the soils. Nitrogen is deficient 

 in 9 only, most of the soils containing very fair proportions of this constituent, and 

 in 3 cases alone could the amount of total lime present be described as low, although 

 in 19 cases the amount of immediately available lime in the form of carbonate 

 appears to be deficient." 



A table is given which classifies the soils with reference to their 

 deficiencies in the different constituents, aud suggestions regarding the 

 use of fertilizers are made. 



Analyses of (> Carriacou soils are reported. These soils were found 

 to be rather light loams, fertile, and with excellent drainage, bnt very 

 susceptible to injury by drought. The rainfall of this island is so low as 

 to render the cultivation of the majority of tropical crops necessarily 

 unsuccessful. "The only promising industry for this island appears 

 to one to be the growth of sisal hemp." 



Soil temperatures at different depths, P. Sollied (Norsk Land- 

 mansblad, 1896, No. 34, pp. 402-405).— The observations of the soil tem- 

 peratures at different depths at the agricultural schools at Aas and 

 Jousberg, Norway, commenced in 1892 (E. S. E., 6, p. 199), have been 

 continued, and the results for the year November, 1893, to October, 

 1894, are given. As before, the monthly averages for the thermometer 

 readings have been calculated. They are given in the following table: 



