92 REPORT ON BOTANY, MDCCCXLT : 
respects consist of perfectly tasteless and scentless water, 
usually appear within ten or twenty minutes after rain or 
watering the plant. If the plants had become withered before 
watering, the upper leaves first erect themselves, the branches 
follow next, and thus it goes on to the lower leaves. The 
capsules also, when quite at rest, are in the habit of opening 
as soon as the drops appear after the water. The drops like- 
wise disappear again, and that in a very different manner. 
Sometimes they are suspended without any change for the 
whole of the day, at other times they disappear again in 
half an hour. The author could not attribute this to 
mere evaporation, and made the following experiments : — He 
managed to attach a drop of common water, of about the 
size of the drops in question, by means of a fine needle, to 
the edge of the leaf, at a place where there was no aper- 
ture to the nerves. This drop was to he perceived for a 
considerable time after, the other drops which had made their 
appearance at the apertures of the nerves, had all disap- 
peared. The author, in order to proceed with still greater 
security, took off a drop, that had made its appearance, with 
great caution from the crenature, and attached it to another 
part of the leaf ; this also was to be seen unchanged after a 
long time, whilst the other drops attached to the crenatures 
had disappeared. The appearance of the drops, therefore, on 
the plants, the author adds, cannot always be considered as a 
secretion of the superfluous nourishing sap ; but it seems, on 
the contrary, that the sap rises so rapidly, and in such great 
quantity, that the same cannot be immediately and properly 
distributed, and consequently issues at all apertures. As 
soon, however, as the distribution of it has taken place in the 
cellular tissue, the part temporarily secreted, in the shape of 
drops, is also imbibed, and applied to further distribution in, 
and nourishment of the plant. The author instituted similar 
experiments with the leaves of the cauliflower, and the result 
was the same ; he also observed the same occurence sometimes 
when the drops had accidentally got displaced. Although the 
drops of the cauliflower are larger than those of the Impa- 
tiens nolitangere, they yet disappear more rapidly, very 
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