TOBACCO 197 



the poles. With the best grades of high-priced 

 tobacco it is now more usual to harvest the leaves 

 singly and string them for curing by passing a 

 needle tlirough the thick midrib. As the lower 

 leaves always mature first, this plan enables the 

 planter to make two or three cuttings and harvest 

 each leaf in the best condition of ripeness, and thus 

 gives a greater uniformity in the product. Cigar 

 tobaccoes are generally allowed to cure naturally 

 without the use of heat. With some of the plug 

 tobaccoes artificial heat is usually employed in the 

 curing barns. In either case great care and consider- 

 able experience is required during the curing pro- 

 cess. Tobacco barns are generally so built that they 

 may be either closed tightly or given free ventilation 

 according to the state of the weather and condition 

 of the contents. The curing of tobacco depends 

 upon the action of internal ferments, called enzymes, 

 such as are concerned in the ripening of fruit and in 

 producing the autumn coloration of forest leaves. 

 Drying must not proceed too rapidly or these enzymes 

 do not have time to do tlieir work, and instead of the 

 rich attractive brown the tobacco will turn to a dirty 

 green. That this change of color is due to activities 

 taking place within the living cells of the leaf may 

 be conclusively shown by crushing the cells over 

 certain areas; as when a name is written heavily on 

 the leaf with a pencil, such injured areas remain green 

 upon drying, and the name appears in green letters 

 upon the brown background of the leaf. A rather 

 moist air should be maintained in the tobacco house 

 during the first few days of curing, in order to 



