4 
N. C. AGRICULTURAL EXPERIMENT STATION. 
a wide range of territory, including portions of the tropical and 
temperate zones. The fine aromatic flavor, upon which the value 
largely depends, seems to be most properly developed in the plant 
by the agencies of high temperature and moisture. 
Little can be done, however, to change the influences of climate, 
but the other conditions that must be fulfilled in order to succeed in 
the cultivation of the crop may be modified to produce the desired 
result. 
The quality also depends, to a large extent, on the character of 
the soil. While the plant thrives best in a soil rich in fertilizing 
ingredients, too much organic matter tends to make the leaves coarse 
and heavy at the expense of quality. The finest leaves are pro¬ 
duced on a light sand, or sandy loam, having an average amount of 
organic matter. The soil seldom possesses the elements of plant 
food in such a form as to be conducive to the production of a fine 
tobacco leaf This deficiency must be supplied by the application 
of suitable fertilizers. Care must be exercised in the selection of 
the proper elements of plant food, for ingredients might be taken 
up by the plant which would be detrimental to its burning qualities, 
or other properties which give to it its value. 
The various properties of the leaf are thus more or less affected 
by the climate, soil, fertilizers, mode of cultivation, time of harvest¬ 
ing, etc. 
While, therefore, it is permissible to trace out the relations between 
Nature and the proportions of the various constituents, we must also 
consider the treatment to which the plant is subjected after it has 
been removed from Nature’s laboratory, and note what effect this 
subsequent treatment has on the finished product. There are various 
processes of curing, fermenting and flavoring which affect, in one 
way or another, the quality and composition of the commercial 
article. The experiment already made only includes two of the 
many different processes, namely, curing by the leaf process and the 
stalk process. 
The Constituents of Tobacco. 
The constituents of tobacco are present in varied proportions in 
different tobaccos, and the variation is still more noticeable in the 
commercial article which has been subjected to the different processes 
of curing and manufacture. The results of chemical analysis show 
that the same constituents, with a few exceptions, are found to be 
present, to a greater or less extent, in all varieties. The constitu¬ 
ents already identified in the leaf of the tobacco plant are as follows; 
Nicotine (C 10 H U N 2 ).—This alkaloid is the active principle of 
tobacco. It consists of a volatile oily substance, and possesses a strong 
tobacco odor. It has been ascertained that nicotine is present in the 
largest quantities in the ripe leaf, while the percentage decreases in 
the young and overripe leaves. Though the narcotic effects must 
