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SCIENCE PROGRESS 



acid (especially the latter) was noted in the good soil. Lime 

 was present in abundance in the subsoil in both cases ; and, 

 quoting from the paper under review, " as regards the mechani- 

 cal and chemical composition, temperature and moisture deter- 

 minations, little can be found to discriminate between the two 

 soils and though some of the factors of production are slightly 

 better in the good soil the differences seem too small to be 

 significant." 



Further examination, however, enabled the authors to account 

 to some extent for the difference in the type of growth of the 

 herbage observable in the fatting and non-fatting fields. The 

 soils of the good fields possess one marked characteristic : they 

 contain definitely more free ammonia and more nitrate in the 

 early part of the season, though the difference disappears 

 later. The accompanying table gives the figures obtained : 



Nitrogen as Nitrate and Ammonia in parts per Million of 



Dry Soil, 1910. 



At the same time it was found that soil from the good field 

 underwent nitrification at a greater rate than that from the 

 bad field. These are the most significant differences observed. 

 It is evident that the better type of grass in the fatting fields 

 is produced as a result of a greater food supply, though the 

 floral type remains the same. 



With minor divergencies, all the details given hold equally 

 for the soils of the other two centres, whether the physical 

 conditions of the soils in the pairs of fields were similar or 

 dissimilar. In the authors' words, "... the amount of nitrates 

 and ammonia in the good soils is always far above the quan- 

 tities found in the bad soils in the early part of the year. Here 



