This section is from the book "Commercial Gardening Vol1", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Sand consists of small pieces of hard rock that have been broken down into various degrees of fineness or coarseness from such rocks as silica or flint, sandstone, quartz, granite, etc, by the action of the weather and water. The peculiarities of sand are: it is hard and gritty; it will not float in water; its particles will not cohere readily even when wet, nor can they be moulded into any shape for any length of time; it will not hold water; it absorbs and radiates heat readily; and in a fine condition its particles are blown about easily by the wind when dry.
When mixed with clay, peat, loam, and other soils sand is useful because it renders the soil more porous, warmer, easier to work, and better aerated - all valuable properties for plant growth.
 
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