22 FLAX CULTURE AND PREPARATION 



harsh but strong fibre. In hot climates the plant differs 

 materially from that grown in temperate zones. In the 

 former the plant branches out considerably, produces a 

 medium length of straw and quality of fibre and a large 

 quantity of seed. 



In the more temperate zones, the straw frequently attains 

 a height of 40 in. with few branchings and seed bolls. 



The short hot summers of Russia produce flax of rapid 

 growth, strong in fibre but never of fine quality. 



23. Soil. Soil is the decomposed material of the rock over 

 which it lies. 



The chief components of soil are clay, sand, calcareous 

 substances and humus, i.e., decomposed vegetable matter. 



The chief constituents of clay are silica and aluminium. 

 Its chief characteristics are tenacity, retention of water and 

 coldness. Sand is destitute of organic matter and plant 

 food, but it forms a useful mixture with clay by improving 

 its texture, facilitating the circulation of air and the addition 

 of warmth. The calcareous substances include chalk and 

 lime which, though deficient in organic matter, sweeten sour 

 soils by neutralizing the acids. 



If the soil, at or near the surface, is all pure clay it is termed 

 cold. 



Heavy soil is so denominated when it contains over 50 per 

 cent, of pure clay. 



A loamy soil is free and open ; it contains from 25 to 30 per 

 cent, of pure clay. 



A sandy loam contains 10 to 24 per cent, of clay and a 

 sandy soil about 6 to 9 per cent, of clay. 



Calcareous soils contain 20 per cent, or more of chalk or lime. 



A good soil contains 70 to 75 per cent, of clay and sand in 

 approximately equal proportions and the balance in calcareous 

 substances and humus of approximate equal quantities. It is 

 healthy, well drained, free from weeds, surface and stagnant 

 water. 



When cultivated by growers who exercise judgment, science, 



