6 BULLETIN 79, TJ. S. DEPARTMENT OP AGRICULTURE. 



Table I. — Loss in dry weight in air curing tobacco leaves: (A) by the priming method. 

 (B) by curing on the stalk — Continued. 









B.- 



—Leaves cured on stalk. 









Tobacco leaves. 



Havana Seed; 1908 

 (partially cured). 



HaUaday; 1909. 



Halladay; 1910. 





Leaf 



web. 



Stems. 



Whole 

 leaf. 



Leaf 

 web. 



Stems. 



Whole 

 leaf. 



Leaf 

 web. 



Stems. 



Whole 

 leaf. 



Weight of 100 dry leaves: 



Uncured grams. . 



Cured do 



Loss of weight in curing, per 



437.1 

 312.4 



28.6 



72.5 

 70 



45.3 

 41.4 



.89 



27.7 



165.9 

 134 



19.2 



27.5 

 30 



28.4 



26.4 



1.20 



18 



603 

 446.4 



26 



100 

 100 



73.7 

 67.8 

 .98 



25 



342.9 

 238.1 



30.6 



70.2 

 69.5 



42.3 

 40.3 

 .59 



30 



145.4 

 104.6 



28.1 



29.8 

 30.5 



27.9 



23.1 



3.31 



24.8 



488.3 

 342.7 



29.8 



100 

 100 



70.1 

 63.4 

 1.38 



28.4 



297.6 

 230 



22.7 



70.7 

 72.6 



38.6 

 37.3 



.43 



22.3 



123.1 



86.7 



29.6 



29.3 

 27.4 



23.2 



18.6 

 3.74 



25.9 



420.7 

 316.7 



24.7 



Leaves: 



Uncured per cent. . 



Cured do 



Weight of pure ash in 100 

 leaves: 



Uncured grams.. 



Cured do 



Loss of ash in curing, per cent. 



Loss of organic matter in 

 curing. per cent. . 



100 

 100 



61.9 



55.9 



1.42 



23.3 



The content of pure ash is of special interest as serving as a check 

 on the original uniformity in size and composition of the uncured 

 and cured leaves of each series, since there could be no actual loss of 

 ash from the whole leaf. The differences found between the uncured 

 and the cured leaves are so small as to be negligible, and they furnish 

 strong evidence of the uniformity in size and composition of the 

 original duplicate samples. We are safe, therefore, within very 

 narrow limits, in regarding the observed differences in weight be- 

 tween the uncured and cured leaves as representing the true loss in 

 weight of dry matter during the curing process. 



Regarding the total loss in weight of the whole leaf, it will be seen 

 that the values ranged from about 11 to about 14.5 per cent when 

 the curing was completed. In the case of the 1909 sample of Halla- 

 day tobacco the loss is undoubtedly below normal, and the low value 

 for the whole leaf is due mainly to the slight loss in weight of the 

 leaf web. It is not known to what extent unfavorable weather 

 conditions during the curing may have influenced the result, but by 

 reference to Table IV, section A (p. 18), it will be seen that the sam- 

 ple was very low in starch content, and this constituent is the most 

 important of all as regards loss in weight in curing. (See also p. 31.) 

 Disregarding this sample, the loss in weight in the experiments is 

 surprisingly uniform in view of the differences in types of leaf and 

 the varying weather conditions during the curing. In the two cases 

 where the curing was interrupted before it was complete, the loss in 

 weight of the whole leaf was nearly as great as in complete curing, 

 showing that the principal changes in composition to which the loss 

 in weight is due proceed rapidly. In the case of the Havana Seed 



