420 EXPERIMENT STATION EECORD. 



terial of low refractive index and associated witii comparatively large propor- 

 tions of quartz, (2) soils containing isotropic material of higher refractive 

 index, relatively large proportions of olivine, and little or no quartz, and (3) 

 fcoils characterized by the relatively larger number of mineral species readily 

 recognized and by the occurrence of well-developed lime-soda feldspars. " The 

 presence of relatively large pi'oportions of glasses in certain soils derived 

 mainly from volcanic ejecta . . . suggests that with such soils the inorganic 

 soil material would be more readily and quickly modified than with soils of 

 other origin." 



Some unusual soils that occur in Oregon, M. M. McCool {Jour. Amer. Soc. 

 Agron., 6 {lOJJf), No. Jf-5, jjj)- J59-16.'f). — This article deals with certain soils 

 occurring in central Oregon which are characterized by a very loose more or 

 less disintegrated pumice layer which extends to depths of from 8 to 12 in. 

 The upper 4 in. is darker gray in color than the material underneath, and as 

 a rule a very coarse pumice layer, which varies in thickness from 8 to 12 in., 

 lies below the disintegrated mass. Beneath this layer to a depth of approxi- 

 mately 40 in. the texture is somewhat finer. 



The results of physical and chemical studies of these soils show a high per- 

 centage of coarse gravel and fine and very fine sand in the upi)er layers, a low 

 real specific gravity, an extremely high capillary water capacity, a high 

 available water capacity, a low total content in soluble salts, and an abnor- 

 mally high content of i)otassium, calcium, and magnesium. A miueralogical 

 study shows that these soils are composed of juaterial derived from both basic 

 and acidic rock. 



It is thought that little can be accomplished with these soils until the organic 

 matter is malerinlly increased and until mineral fertilizers are added. 



The Hauraki Plains: Some notes on the soils, B. C. Aston {Jour. Agr. [New 

 Zeal.], S {19U), No. 6, pp. 565-574, figs. 5).— A general description of the flora 

 of the area and analyses of the soils are given. The latter show that the soils 

 may belong to extreme types of clays, peats, and sands, and this is confirmed 

 by the great diversity in the flora. " Improvement of the soils may be effected 

 by liming the tenacious clays and claying the peaty soils." Experiments in 

 mixing the abundant humus matters with clay soil and a systematic soil sur- 

 vey of the area are recommended. 



Malayan rubber and coconut soils, M. Barrowcliff {Agr. Bui. Fed. Malay 

 States, 2 {lOIJf), No. 12, pp. 328-331). — This article presents the author's views 

 obtained from an examination of rubber and coconut soils in the Malay States, 

 and includes a number of analj'ses of good and poor soils. 



Rubber is grown on various kinds of soil, but the most productive are stated 

 to be the light sandy, well-drained soils composing the undulating lauds broad- 

 ening down from the granitic mountains and the flat peaty coast soils when 

 these are well drained. The first are low in nitrogen and jwtash, but apparently 

 contain enough for rubber. They are deficient in i>hosphoric acid, but appar- 

 ently do not need lime. Terfect drainage and the presence of sufficient organic 

 matter are soil conditions favorable to rubber cultivation. 



Coconuts are grown on various kinds of soils, but apparently do esiiecially 

 well on the clayey peat lands of the coast. These soils contain considerable 

 organic matter and are well supplied with nitrogen, potash, and phosphoric acid. 

 They are infertile if poorly drained, but drainage needs to be less deep and 

 thorough than for rubber. The heavy clays are not suited to either rubber or 

 coconut culture. 



The chemical or physical nature of colloidal aluminum silicates contain- 

 ing water, R. Gans {Ccnthl. Min., Geol. ii. Paliiontol., 1013, Nos. 22. pp. 699- 

 112; 23, pp. T28-lJfl; «&«• in Cliem. ZentbL, 1914, h No. 3, pp. 286, 287).— In 



