LETTERS FROM ALABAMA. 193 
an umbrella, as locum tenens of a parasol ; but to 
pursue swallow-tailed butterflies, with a net in one 
hand and an umbrella in the other, would be not 
quite the thing.” There is, moreover, a degree 
of bodily languor and weakness induced by exces- 
sive perspiration, which depresses the mind and 
blunts scientific zeal, if not strongly combated. 
Of the prostration of strength arising from this 
cause, you may form an idea from a single fact. 
Sitting down in my room alone to write, without 
any previous exercise to warm me, almost un- 
dressed, 1 had not written half a page, when I 
found, where my hand had lain, a little pool of 
water on the paper, as much as a teaspoon could 
contain, the exudation from my hand alone during 
those few minutes. The morning hours, therefore, 
are the only part of the day that can habitually be 
rendered effective to science ; for very few insects 
or birds, comparatively, are abroad in the evening, 
except the night-fliers. My usual plan is, to take 
a long walk through the forest in the morning, 
before the sun is very high ; and in the heat of the 
day, if business permits, arrange my captures, 
write, or paint insects and flowers. 
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