SCHLOSSING. _Sur la production de la nicotine par la culture du Tabac._ Compt. Rend. Acad. d. Sc. (Paris), 1910. Vol. 151, p. 23. CHAPTER VI THE CURING OF TOBACCO LEAF OBJECTS OF CURING. METHODS. THE CURING OF TOBACCO LEAF The "curing" of tobacco leaf is the process of drying out which has for its object the following specific actions: (1) The expelling of the sap and superfluous moisture. (2) The completion of the "yellowing" process and the fixing of the desired color. (3) The preservation of the juices, etc., which give the characteristic flavor and aroma. (4) To give the necessary toughness and suppleness to the leaf. The first part of the curing is done by the grower in curing sheds on the farm immediately after the cutting of the crop; the final part, or the fermentation part is usually done by the leaf dealer or manufacturer in special buildings called leaf-houses. There are three methods of curing in use by the growers, i. e., sun curing, air curing, and artificial heat curing. In the case of the tobacco known as _Perique_ the curing process is more or less peculiar to itself. "Sun" and "air" curing are much slower processes than the curing by artificial heat. All cigar leaf tobacco is sun-cured, and as a general rule pipe smoking and chewing tobacco are cured by artificial heat. For the purpose of drying and curing by artificial heat, the leaf is hung up in specially constructed curing houses or sheds. It is found that after the exposure to the sun for the first process of "yellowing" tobacco leaf still contains 1 lb. of water approximately in each plant. The first part of the process of curing consists in drawing off this superfluous moisture. Dry heat is applied at a temperature of 90° F. to 120° F. for about 16 to 30 hours to effect this. A further exposure of about 48 hours at a temperature of 125° or so is necessary to complete the curing, and fix the color. The stems and stalks being thicker take a longer time and generally require 9 to 10 hours further exposure and a temperature which may range as high as 175° F. before they are fully cured, the temperature being graded hourly until the maximum necessary is reached.