PHYSIOLOGY. 947 
young shoot remained flaccid, but the first and se- 
cond were fresh. Of young plants of oats, which 
had only three leaves, one leaf was exposed to ar- 
tificial cold at 22° which instantly was frozen. ‘The 
root was put into the same cold mixture, but did 
not freeze. We then planted it, and all its parts 
grew well, except the leaf, which had been frozen. 
The same experiment he repeated with a growing 
bean; a leaf of it was frozen in an artificial freez- 
‘Ing mixture, and another fresh leaf was bent in the 
middle upon itself, put into a leaden vessel, and along 
with it the frozen leaf, which had been previously 
thawed. He afterwards put the vessels upon the 
top of the freezing mixture. ‘The surfaces of the 
two leaves froze as far as they came’ in contact with 
the vessels between 15 and 17°, the atmosphere 
being at 22°. The frozen leaf froze much sooner. 
These experiments were repeated, and always with 
the same result. The juice of spinage and cabbage, 
when squeezed out, congealed at 29°, and thawed 
dgain between 29——-30°. ‘Uhese juices, frozen in a 
leaden vessel, were put into another, with a cold 
mixture at 28°. A growing fir-shoot, and a bean- 
leaf were put upon the frozen liquid which in that 
place thawed in a few minutes. The leaves had the 
same ellect when removed to other frozen spots, 
Schoepi made the following experiments in North 
America. He bored holes in different stems, which 
he again closed up. :In one of ‘the holes he puta 
thermometer at frosty weather, to compare the in- 
terna! heat with that of the atmosphere. The re- 
sult, however, differed at different times, and in pro- 
Be OD te portion 
