No. 4.] HARVESTING AND CURING TOBAC(X). 77 



brought at once to the very important fact that ciiriiuj is a 

 lirtiifj or dial process, and that leaves 'prematurely killed 

 cannot he successfully cured. The changes taking place iu 

 the leaf in the barn are strictly analogous to those occurring in 

 the growing plant in the tield. The leaves, of course, cease 

 to grow, hut the breathing or respiration process continues 

 until they die from starvation or lack of water. Cut off from 

 their supply of raw material, they cannot continue to manu- 

 facture additional food to maintain the vital processes. They 

 use u]) the reserve supply stored up during the ripening period 

 in precisely the same manner as an animal may live for many 

 da_\ s without food, though losing in weight, because the reserve 

 food supply in the tissues it utilized in maintaining life. In 

 brief, therefore, curing is a vital or living process, whereby 

 certain constituents of the leaf, such as starch, which tend to 

 nuike it brittle and chaifv, are broken up, and certain other 

 desirable constituents, such as the so-called " gnm," are corre- 

 spondingly increased in amount. Along with these changes in 

 composition the color changes from green to yellow, and this 

 shows that the leaf has reached the dying stage. As soon as 

 the leaf is dead, the brown color quickly ajipears, and though 

 there are some further changes after the leaf dies, these can 

 take place at almost any stage while the tobacco is in bulk 

 or during the sweating and aging. 



The Most Favokabi.e Coxditioxs for Curing. 

 The important fact to keep in iniiul here is that the leaf 

 must be kept alive till the first stage of the curing is com- 

 pleted, i.e., until the yellowing begins, and this brings us to 

 the question of the most favorable conditions for curing. The 

 first change to be noticed in the leaf is wilting, caused by the 

 loss of water. This wilting hastens the curing, and is desir- 

 able, provided it does not go too far. Rapid drying kills the 

 leaf before there is time for the changes already discussed to 

 take place, and the result is that the tobacco " hays do\m." 

 Gradual and not rapid drying is, therefore, one of the favor- 

 able conditions for curing. The leaf is also killed by ex- 

 tremes of temperature, so that artificial heat, if used at all, 

 nuist be applied with caution, and the temperature should not 



