276 
Journal of Agricultural Research 
Vol. VII, No. 6 
The analyses recorded in Table I show that the grain contains a very 
high percentage of ash, that calcium is by far the most abundant con¬ 
stituent, that nearly as much magnesium is present as is contained in the 
three other parts of the leaf taken together, but that a smaller amount of 
potash is found in the bodies than in any other class of leaf material 
studied. Of the organic acids, citric and malic are abundant in the grain, 
while oxalic acid is present in a much smaller percentage than in any of 
the other classes of material. These data indicate that the grain ma¬ 
terial must be a mixture of citrates and malates, chiefly of calcium, with 
some magnesium and a little potassium. Nicotin seems to enter into 
the composition of the grain also, since about 1.5 per cent of that sub¬ 
stance was found in an analysis of one sample of grain. The totals of 
the percentages of substances determined indicate that the grain (77.73 
per cent total determined) contains little material other than these sub¬ 
stances. There remains in this case only about 22 per cent undetermined, 
and this must account for cellulose, nicotin, and other nitrogenous com¬ 
pounds, sulphur compounds, and phosphoric acid, as well as small 
quantities of sodium, iron, aluminum, etc., while in the three other classes 
these undetermined substances constitute in each about 70 per cent. 
CORRELATION OF THE GRAIN WITH BURNING QUALITY 
Although persons experienced in the handling of tobacco consider that 
a well-developed grain is an indication of good quality, particularly with 
reference to the bum, it seems that this is a matter of practical experi¬ 
ence with them rather than a factor permitting definite discussion or 
explanation. 1 They assert that a “close-grained” leaf will bum poorly, 
while one possessing an “open grain” will have a greater fire-holding 
capacity. Recently, in the course of interviews with packers and manu¬ 
facturers in Lancaster County, Pa., these observations have been found 
capable of substantiation by microscopic examination. The writer 
requested each of several practical tobacco men to select, on the character 
of the grain alone, what he considered to be a good-burning and a poor- 
burning leaf. In making this selection the leaf was stretched and while 
taut was allowed to pass slowly through the fingers, usually accompanied 
by the remark that the leaf showed an open grain or that it was close- 
grained. The leaves designated as poor-burning (close-grained), invari¬ 
ably possessed a hard texture—that is, something of the nature of the 
softer grades of paper—always showed poor elasticity, and rarely ex¬ 
hibited grain bodies on the surface. On the other hand, the leaves judged 
to be good-burning (showing an open grain) were comparatively soft in 
texture, elastic, and usually possessed grain bodies sufficiently large to 
1 See also Hayes, H. K., East, E. M., and Beinhart, E. G. (4, p. 28). The authors used seven classes to 
indicate the prominence of grain in considering the quality of the strains studied. 
