1919] Pendleton: A Study of Soil Types 475 



staut throughout the several representatives of the type. In some 

 cases, the differences or similarities are more clearly seen in the total 

 analyses, and in other cases, they appear in the acid analyses and not 

 in the fusion analyses. Within any series the variations between 

 analyses of any one type are about the same as the variations from 

 type to type. There are many other papers 37 which provide material 

 for similar comparisons. 



A paper by Van Dyne and Ashton 38 reports chemical analyses for 

 lime, phosphoric acid, potash, and nitrogen on the samples collected 

 in the course of the survey of Stevens County, Washington. Though 

 sometimes there is a much greater range within a type than between 

 types, in a general way the analyses for any one type agree quite 

 well. As a whole the chemical analyses seem to show that the field 

 criteria are also a basis for grouping soils into certain chemical 

 groups. It should be mentioned that the work of Blair and Jennings, 

 also that of Van Dyne and Ashton, deals with individual areas, and 

 not with samples from several scattered areas. The work of Praps and 

 Williams, and the original work here reported represenl scatti red 

 areas. 



The Greenhouse Cultures 



By far the most interesting results were obtained in the pot culture 

 work. It is realized that there are variations in the physical nature 

 of the samples of a given type, yet since these samples were collected 

 with considerable care by one familiar with field classifications, the 

 samples so selected should be fairly representative of the type. It is 

 probable that if all the soils in each of the types used were exactly the 

 same in texture, i.e., if the mechanical analysis showed the same 

 results for the several soils, the crops produced on the several soils of 

 a type would be less divergent in appearance or weight. Yet it is 

 not at all likely that the crops would be the same. Pot cultures pre- 

 sume that the conditions in all the pots can be kept uniform, but this 

 is obviously impossible. Greenhouse work is subject to many interfer- 

 ing factors. Nevertheless, the results are believed to be significant, 



37 Williams, and others, Report on the Piedmont Soils, North Carolina Dept. 

 Agr., Bull. 206, 1915. 



Fraps, G. S., Composition of the Soils of South Texas, Texas Agr. Exp. Sta., 

 Bull. 161, 1913; Composition of the Soils of the Texas Panhandle, ibid., Bull. 

 173, 1915. 



3 8 Van Dyne and Ashton, Soil Survev of Stevens County, Washington, Field 

 Operations, U. S. Bur. Soils, 1913, pp. 21*65-2295. 



