INORGANIC COMPOSITION OF SOME AMERICAN SOILS. 19 



Silt. — Minerals other than quartz, 48 per cent. Potash feldspars 

 ( orthoclase) , 5 per cent. Chlorite, biotite, muscovite, epidote, 

 hornblende, tourmaline, rutile, and magnetite are also present. 



(9) MARSHALL SILT LOAM, SOIL. 



No. 4 sand.- — Minerals other than quartz, 4 per cent. Potash 

 feldspars (orthoclase), 2 per cent. Muscovite, 1 per cent. Glass, 

 biotite, and muscovite are also present. 



No. 5 sand.- — Minerals other than quartz, 20 per cent. Potash 

 feldspars (orthoclase), 10 per cent. Muscovite, 2 per cent. Biotite, 

 magnetite, epidote, albite, labradorite, oligoclase, tourmaline, zircon, 

 garnet, and augite are also present. 



Silt.- — Minerals other than quartz, 34 per cent. Potash feldspars 

 (orthoclase), 4 per cent. Muscovite, 4 per cent. Biotite, magne- 

 tite, epidote, albite, labradorite, oligoclase, tourmaline, rutile, glau- 

 cophane, hornblende, and augite are also present. 



(10) MARSHALL SILT LOAM, SUBSOIL. 



No. 4 sand.- — Minerals other than quartz, 7 per cent. Potash 

 feldspars (orthoclase), 3 per cent. Muscovite and phlogopite, 2 per 

 cent. Biotite is also present. 



No. 5 sand.- — Minerals other than quartz, 16 per cent. Potash 

 feldspars (orthoclase and microcline), 5 per cent. Muscovite, 5 per 

 cent. Biotite, magnetite, hornblende, epidote, oligoclase, albite, 

 tourmaline, and garnet are also present. 



Silt.' — Minerals other than quartz, approximately 50 per cent. 

 Potash feldspars (orthoclase and microcline), 8 per cent. Musco- 

 vite, 7 per cent. Biotite, hornblende, magnetite, axinite, epidote, 

 augite, zircon, apatite, tourmaline, labradorite, and albite are also 

 present. 



(11) GLOUCESTER STONY LOAM, SOIL. 



No. 4 sand.- — Minerals other than quartz, 10 per cent. Potash 

 feldspars (orthoclase and microcline), 2 per cent. Muscovite, 5 per 

 cent. Biotite, magnetite, hematite, phlogopite, hornblende, ande- 

 site, hypersthene, garnet, diopside, tourmaline, and oligoclase are 

 also present. 



No. 5 sand.- — Minerals other than quartz, 15 per cent. Potash 

 feldspars (orthoclase and microcline), 2 per cent. Muscovite, 5 per 

 cent. Biotite, phlogopite, magnetite, hornblende, apatite, rutile, 

 tourmaline, augite, garnet, epidote, and albite are also present. 



Silt.- — Minerals other than quartz, 60 per cent. Potash feldspars 

 (orthoclase), 2 per cent. Muscovite, 30 per cent. Biotite, phlogo- 

 pite, garnet, epidote, sillimanite, hornblende, zircon, labradorite, 

 and rutile are also present. 



