SOLANACE^ 6oi 



removes large quantities of nitrogen, potash, and phosphoric 

 acid from the soil. Consequently, the plant is rich in these 

 valuable plant nutrients. In fact the leaves and stalks 

 make excellent fertihzers, and are so used in tobacco sections. 

 Curing Tobacco. — This process consists in removing the 

 moisture in the leaves and stems in such a manner as to 

 produce a uniform color and texture in the leaves. Artificial 

 heat was first employed in the curing of tobaccos in 1812. 

 Wood fires were used up to the year 1828, about which time, 

 flues, and charcoal fires came into use. Flue-curing entirely 

 replaced charcoal fires in 1865. Flue-curing produces a 

 bright yellow leaf. The green tint is obtained by harvesting 

 the leaf before it is fully ripe. The dark export tobaccos are 

 cured with open hard-wood fires. Light tobaccos may be 

 air-cured, and such are used for pipe smoking, and cigarettes. 

 White Burley tobacco, so highly prized for twist and plug 

 chewing tobaccos, is usually air-cured. The yellow and 

 mahogany tobaccos are cured by flues. The process takes 

 about four days. The broad leaf and Havana seed leaf 

 varieties of the Connecticut Valley are air-cured. They are 

 domestic cigar' tobaccos. Curing is often carried on in 

 specially constructed barns with horizontal ventilators. It 

 usually takes about two months to air-cure tobacco, and 

 less time if artificial heat is used. After the leaves have been 

 left hanging for a long time, they are packed closely in boxes, 

 where they are left undisturbed for several months. When 

 warm weather sets in, a process of fermentation is set up in 

 the cases, during which process certain important changes 

 take place. Fermentation may be brought about after a 

 shorter period of drying than is used in the preceding 

 method, by placing the leaves in piles in a warm, moist at- 

 mosphere. When the temperature reaches 125° to i3o°F., 

 the piles are opened and heaped up again. The piles are 



