Vegetable Statlcks. 39 
to which fucceeded a moderate warmth. 
Frozen concave clouds therefore, by their 
great reflexions, produce a vigorous hear, 
and the fame when refolvcd exceflive 
cold. 
Whence we fee that blafts may be occa- 
fioned by the refleXions of the clouds, as 
well as by the above mentioned refraXion 
of denfe tranfparent vapors. 
July 21. I obferved that at that feafon 
the top of the Sunflower being tender, and 
the flower near beginning to blow , that if 
the Sun rife clear the flower faces towards 
the Eaft, and the Sun continuing to (hine, 
at noon, it faces to the South, and at 6 in 
the evening to the Weft : And this not 
by turning round with the Sun, but by nu- 
tation i the caufe of which is, that the fide 
of the ftem next the Sun perfpiring moft, it 
fhrinks, and this plant perfpires much. 
I have obferved the fame in the tops of 
Jerufalem- artichokes and of garden « beans 
in very hot Sun-fhine. 
Experiment X. 
July 17, I fixed an Apple 'branch 3 
D 4 feet 
