243 



the soil becomes light gray in color and, because of this color, is called gray 

 or lead sand. 



Below this Hght colored layer is found, sharply separated from it, a 

 yellow to brownish looking soil, the deeper layers of which gradually be- 

 come lighter. Here, the sand grains show mixtures of ferric-oxid or ferric 

 hydrate. Then comes the white raw sand, still but little affected by weather- 

 ing. The uppermost humus soil layer is found to be most weathered and the 

 layer most impoverished by leaching. If the leaching of such an upper soil 

 layer, under the influence of the raw humus deposited on it, be carried to a 

 given stage, the action of the salts in the soil on the soluble humic acid must 

 cease, the salts then remain in solution and can penetrate to the lower layers 

 of the soil. If they come in contact here with soluble salts, they are precipi- 

 tated and coat the separate soil grains with a structureless layer of organic 

 substances. Under the microscope, I found the sand grains covered with 

 brown, chart-like etchings. If this process keeps up, the precipitated or- 

 ganic substances finally cement the separate sand grains into compacted 

 layers below the lead sand, — meadow-ore has been produced. 



Meadov/-Ore. 



According to Ramann's explanation of the production of meadow-ore, 

 given in the previous section, this is a humus sand stone. It occurs in var- 

 ious forms and first of all as "Branderde" or "Orterde," which has a white 

 easily pulverized form and shows a large content of organic substances. 

 This is formed in rich soils which are but little changed unfavorably. The 

 real swamp ore is a firm, stone-like, hard mass, deposited on easily pulver- 

 ized or loose soil layers, with a medium content of organic substances 

 and a brown to black color. This is the form most widely distributed in 

 North Germany (Liineburger moor). Besides this, there is a lighter brown 

 swamp-ore which is ytry firm and tough and holds but small amounts of 

 organic substances. This is the hardest form, offering the greatest resistance 

 to a working of the soil and frequently occurring in great thickness. 



In judging the processes of leaching, an analysis taken by Graebner^ 

 from Ramann's" work may be useful. The swamp ore soil in the Main 

 Forestry District Hohenbriick in Pomerania contained in its different 

 layers : — • 



(a) Lead sand, which was 15 to 20 cm. thick and contained 1.05 per 

 cent, of organic substances^. 



Soluble in Residue insoluble in 



Hydrochloric acid. Hydrochloric acid. 



Potassium 0.0076 per cent, of the soil 0.618 



(Sodium o.oiii 



Calcium o.oiio 



Magnesia 0.0026 



(Manganous oxid 0.0032 



Ferric oxid 0.0964 



Aluminum oxid 0.0268 



Phosphoric acid 0.0058 



0.167) 



0.060 



0.020 



0.060) 



0.450 



0.650 



0.043 



Total content except silicic acid. 0.1645 2.068 



1 Paul Graebner, Handbuch der Heidekultur. Leipzig, Wilh. Engelmann. 1904, 

 p. 194. 



2 Die Waldstreu, Berlin, 1890, p. 30. 



3 Ramann in his "Bodenkunde" 1905, p. 166, gives the same analysis without 

 the elements enclosed in parantheses. 



