Vegetable Statich. 
and trees, in proportion to the greater or 
lefs convergency of the Sun’s rays. 
The learned Boerhaaue , in his Theory of 
Chemijlry , Dr. Shaw's Edition, p. 245. ob- 
serves, “ That thofe white clouds which ap- 
c< pear in Summer-time, are as it were fo ma- 
“ ny mirrors, and occafion exceflive heat. 
“ Thefe cloudy mirrors are Sometimes 
■“ round, Sometimes concave, polygonous, 
£C when the Sace of heaven is covered 
u with Such white clouds, the Sun (hilling 
€f among them, muft of neceffity produce a 
vehement heats fince many of his rays, 
<c which would otherwise, perhaps, never 
u touch our earth, are hereby refleded to 
u us 5 thus if the Sun be on one fide, and 
* c the clouds on the oppofite one, they will 
* c be perfed burning glafies. 
cc I have Sometimes (continues he) ob- 
Served a kind of hollow clouds, full of 
a hail and Snow, during the continuance 
a of which the heat was extreme 5 fince by 
e£ Such condensation they were enabled to 
“ refled much more ftrongly. After this 
“ came a fharp cold, and then the clouds 
* c discharged their hail in great quantity i 
to which Succeeded a moderate warmth. 
“ Frozen 
