34 ^ Of Vegetation. 
But when the cold was fo far relaxed, as 
to have the fpirit in the firft Thermometer 
but 5 degrees above the freezing point, the 
fecond 8 degrees, and the 6th 1 3 degrees, 
tho’ it was ftill very cold, yet this being 
fome advance from freezing towards warm, 
and there being confequently fome expan- 
fion of the fap, fevcral of the hardy vege- 
tables grew, ^iz>, fome Ever-greens, Snow- 
drops, Crocus s, which forward hardy 
plants do probably partake much of the na- 
ture of Ever-greens in perfpiring little ; and 
the motion of their fap being confequently 
very flow, it will become more vifeous, as 
in Ever-greens 5 and thereby the better able 
to refill the winter’s cold : And the fmall 
expanfive force, which this fap acquires in 
the winter, is moflly exerted in extending 
the plant, little of it being walled in pro- 
portion to the fummer s perfpiration. 
Supported by the evidence of many of 
the foregoing Experiments, 1 will now trace 
the vegetation of a tree from its firfl femi- 
nal plant in the Seed to its full maturity and 
production of other Seeds, without entring 
into a particular defeription of the flrufturc 
of the parts of vegetables, which has al- 
ready 
