
No. 33.] , 231 
ness. We regret that we are unable to express the influence of the 
rain in figures, but we regard the subject as worthy the attention of 
the tobacco grower. 
The past season, in our crop, ‘‘ fat” leaves occurred chiefly on plants 
that were topped late. We noted that the plants topped August 22 
averaged about two and one-half “ fat” leaves to the plant ; those top- 
ped August 18, averaged one and one-fifth to the plant; those top- 
ped August 17, averaged one to the plant ; those topped August 11 
averaged about one-fourth of one to the plant, and those topped 
- earlier furnished only one “fat” leaf to sixty-five plants. 
OBSERVATIONS CONCERNING POLE BURN, 
With the view of studying the subject of pole burn, we hung Au- 
gust 30 a few plants of tobacco in the green-house, where the condi- 
tions of heat and moisture were in a degree under control. We gave 
air to the house only as the growing plants required it, and in dry 
weather secured a humid atmosphere by sprinkling abundance of water 
upon the floor. 
On September 3, the inner leaves of the plants were noted as feel- 
ing very clammy, but contrary to our expectations, pole burn did not 
appear until September 14, fifteen days after the plants were hung, 
although the average temperature of the house at noon for this time 
was about eighty degrees. 
On September 10, we hung a few plants of tobacco in three barrels 
in the green-house, with the view of making experiments calculated 
to arrest the progress of pole burn. One barrel was thoroughly fumi- 
gated with sulphur fumes before inserting the plants ; the others were 
not treated. After putting in the plants, the barrels were covered 
with canvas to prevent a change of atmosphere within them. On the 
evening of September 13 no pole burn was seen, but on the following 
morning it was visible upon the plants in all the barrels. The par- 
tially cured leaves assumed an oily, translucent appearance, like that 
of oiled paper, and the pole burn appeared, in small whitish spots. 
In these spots the structure of the leaf was already destroyed, the lat- 
ter having little more strength than wet paper. ‘The midribs of the 
leaves were also affected in places with an appearance of mould, beneath 
which their structure seemed to be destroyed. The air in the green- 
house the previous evening showed a temperature of sixty-nine de- 
grees, and was saturated with moisture, as was indicated by the hygro- 
meter. This was the first time that the atmosphere in the house was 
noted as being saturated since August 30. Whether the commence- 
ment of the pole burn was due to this fact or not, we do not know. 
We found that pole burn may be propagated from one plant to 
another by innoculation. We also found that burning sulphur in the 
barrels stopped the progress of the affection, but that it commenced 
again shortly afterward. We placed in one barrel a little of chloride 
of lime, and in a second a little quick-lime, but neither of these was 
effectual in arresting the progress of the affection. 
We submitted specimens of leaves affected with pole burn to Prof. 
Wm. Trelease, a learned fungi specialist of the University of Wiscon- — 
sin, and received the following reply: 
