CHEMICAL ANALYSES OF TOBACCO. 267 



ANALYSES OF CERTAIN OF THE PRINCIPAL VARIETIES OF AMERICAN TOBACCO. 



In Tables I, II, and III are given the results obtained in my analyses of samples of some of the principal varieties 

 of American tobacco. 



With the exception of No. 35, which was furnished by the producer, the samples were furnished by Colonel J. 

 B. Killebrew, special agent for the investigation of the details of the cultivation and curing of tobacco. The samples 

 were numbered and labeled as follows : 



No. 3. Virginia tobacco. Sun-cured ; for manufacturing plug tobacco. 



No. 5. Virginia tobacco. Fire-cured ; for the German and continental trade. Low grade. 



No. 7. Tennessee tobacco. From Clarksville. Fire-cured; for the German and English markets. Gummy. 

 Grown on rich, heavy loam, heavily manured. 



No. 19. Kentucky tobacco (White Burley). From the Mason county district. Air-cured (in sheds, without 

 artificial heat) ; for cutting or plug tobacco. 



No. 10. North Carolina Yellow tobacco (Bright Wrapper). From Granville county. Grown on white or light 

 gray sand. 



No. 28. Louisiana tobacco. "Perique, cured in its juices." (Leaf deprived of midrib.) 



No. 37. Louisiana tobacco. " Perique," air-cured. (Leaf deprived of midrib.) 



No. 35. Connecticut Seed-Leaf. From New Milford. Grown on rich loamy soil, heavily manured. This 

 sample was freshly cured, and had not undergone the " sweating" process. 



No. 30. Connecticut Seed-Leaf. From Hartford, Connecticut. Grown on sandy soil. 



No. 34. Pennsylvania Seed-Leaf. From Manor township, Lancaster county. Grown on a clearing, being the 

 second crop after removing the timber. Eighty bushels of lime were used to the acre, but no manure. 



No. 16. Ohio Seed-Leaf. 



No. 22. New York State Seed-Leaf. 



No. 25. Wisconsiu and Illinois Seed-Leaf. 



The details of the modes of curing and cultivation of these samples are fully set forth in the report of Colonel 

 Killebrew. It is, however, desirable in this place to briefly recapitulate the leading features of the treatment to 

 which the plants have been subjected, in so far as may be necessary for the correct interpretation of the results of 

 the analyses. 



Apart from the difference in character of the soil, the differences in the mode of cultivation between the 

 different varieties relate chiefly to the length of time the plant is allowed to remain in the field after the "top" 

 has been removed. - As soon as the leaf ceases to expand, and the " granulation " due to the distension of the 

 individual cells of the leaf through accumulation of intercellular substance begins, which, in good soil, and with 

 favorable weather, will take place in from two to three weeks after " topping ", the seed-leaf varieties are cut. 

 The heavier tobaccos are, on the other hand, allowed to remain from four to six weeks before cutting, or, in the case 

 of heavy shipping leaf (samples Nos. 5 and 7) until fully ripe and ready to decay. 



Concerning the modes of curing: Sample No. 3 was cured by simple exposure to the sun on scaffolds. 

 Samples Nos. 5 and 7 were cured by open wood fires in close barns, the heat being kept at or below 90 F. (32.2 C.) 

 for two days, after which it was allowed to rise to 125 F. (51.6 C.) and then to 150 F. (65.5 C.), the last heat being 

 continued for twenty-four hours, and the operation being complete in about four days and nights. No. 10 was cured 

 by a very carefully regulated heat in close barns ; the temperature being maintained for thirty-six hours at 90 F. 

 (32.2 C.), and then carefully and systematically raised to 170 F. (76.6 C.), at which it remained for ten hours, 

 the operation being complete in sixty to sixty-five hours, open coal fires or flues being used. Samples Nos. 19 

 and 37 and the seed-leaf samples (Nos. 35, 30, 34, 16, 22, and 25) were cured without artificial heat in sheds, 

 ventilated by doors which are left open during the day, except in very damp weather, and closed at night. 



From the foregoing it is evident that the samples Nos. 3, 5, 7, and 10 were cured with very little or no 

 fermeutation, whereas the other samples must have suffered considerable fermentative change. The process of 

 curing, to which the sample No. 28 (Perique cured in its juices) was subjected, involves a very thorough and 

 prolonged fermentation, with periodical applications of pressure, which last would tend to express the juices of 

 the leaf from the cells and insure an exceedingly thorough and uniform fermentative process. 



METHODS OF ANALYSIS EMPLOYED. 



In preparing the samples for analysis, the leaves'were exposed to the air at ordinary temperatures until 

 thoroughly dry, the whole leaf, inclusive of the midrib, except Nos. 28 and 37, ground to fine powder and preserved 

 in tightly stoppered glass bottles. The different determinations were then made on the air dried leaf by the methods 

 given below, and the results reduced to percentages in the substance, dry at 100 C. 



1. MOISTURE. Five grammes were dried for two hours in the air-bath at 100 C. 



861 



