cai methods : some sort of compromise accordingly became inevitable, and & 

 standard method was adopted and compared from time to time with one or 

 two other methods, which will also be fully delineated in the sequel. How 

 well the method taken as a standard has fitted in with the climatic condi- 

 tions of the country is shown by the repeated agreement between labora- 

 tory results and the recorded experiences of the practical farmer. The 

 alternative course which was open was to adopt improvements in analytical 

 methods as they arose, and thus ensure in all respects up-to-date modes of 

 manipulation, but coupled with an inevitable unconformity to the earlier 

 results of the series. 



In describing the methods employed the collection of soil samples 

 claims first attention. Dr. Wiley rightly says: "The sole object in tak- 

 ing a sample of soil should be to have it representative of the type of soils 

 to which it belongs. Every precaution should be observed to have each 

 sample measure up to that standard. The physical and chemical analyses 

 of soils are long and tedious processes, and are entirely too costly to be ap- 

 plied to samples which are not representative." It will be understood that 

 analyses of soils from cultivated fields, whatever value they may have for 

 the owner of that particular plot, cannot, as a rule, be comprised in an 

 investigation relating to the country at large, or even to the surrounding 

 district ; for a soil that is modified by repeated cropping and manuring, 

 and altered by human agency, cannot be looked upon as typical or repre- 

 sentative of any extended area. The scheme of investigation which the 

 writer had in view aimed, for the greater part, at ascertaining the compara- 

 tive agricultural values of soils over wide tracts of country, and it was ac- 

 cordingly sought to collect, as far as possible, only virgin soils which had 

 not been subjected to modifying influences; in a country such as this, a 

 most difficult and well-nigh hopeless task. 



In the actual taking of the samples for ordinary agricultural chemical 

 analysis the practice has been as follows : The surface of the selected spot 

 ;s lightly scraped with a trowel or other sharp tool, so as to clear away the 

 top growth and surface accumulations of semi-decayed vegetable matter not 

 forming a part of the true soil. A hole with vertical sides is then dug to 

 a depth of twelve inches, and from the sides of this hole thin slices of soil, 

 aggregating from five to ten pounds in weight, are removed, in as uniform 

 a manner as possible, and placed in a suitable bag of canvas, cloth, or other 

 impervious material through which the fine soil will not sift out on trans- 

 port during conveyance to the laboratory. 



On arrival in the laboratory the sample is allowed to become air-dry 

 by being spread out in a thin layer, protected from dust, for some days. 

 Any lumps of soil that there may be are then gently broken down by means 

 of a wooden pestle or rolling-pin, care being specially taken to avoid 

 crushing any mineral fragments. 



Subsequent treatment of the soil thus prepared varies according as a 

 complete mechanical or a more purely chemical analysis is desired. It had 

 been intended to combine the former with the latter in systematically in- 

 vestigating the country's soils, but the exigencies of circumstances rendered 

 such a course, though desirable, quite impracticable. In . connection with 

 the soil survey, therefore, only a restricted form of mechanical analysis waa 

 adopted, and the few instances in which the more complete mechanical dif- 

 ferentiation was made will be dealt with separately at a later stage, where 

 the method employed for that purpose will be outlined. At this point we 

 shall confine ourselves to the operations more closely connected with the 

 purely chemical analysis. 



As previously remarked, the importance of finely divided particles in, 

 a soil, at first vaguely grasped by Tull, has been definitely recognised dur- 

 ing the last quarter-century. It is now understood that, for agronomic 



