225 
blackened and dead in all its leading shoots ; and their astonish- 
ment will be still greater, should they have chanced to leave a 
duplicate of the same species under the shade of some cold 
north wall or building, where it will most probably be found per- 
fectly green, fresh, and uninjured in its wood or branches. 
The rationale of the foregoing facts seems to be as follows. 
In our cold and protracted winters, when the thermometer is 
depressed below the zero of Fahrenheit, the sap vessels of 
all half hardy plants become completely frozen. At the same 
time our sun, during many days in winter, shines out with an al- 
most undimmed brightness and warmth, and, rapidly thawing 
the fluids in these sap vessels, the latter are so distended by 
the sudden melting and perhaps subsequent freezing, as in many 
places to be completely burst and incapacitated from performing 
the functions for which they are intended. Those plants, how- 
ever, which are protected from the sun’s rays, and, consequently, 
from the deleterious etfects of this rapid change in the sap 
from partial fluidity to congelation, but which are, on the con- 
trary, restored to their former state by means of a gradual 
thaw ing, as, for example, by the slowly increasing warmth of 
returning spring, they will, in most cases, be found to have suf- 
fierred little or nothing by the severity of the cold to which they 
have been exposed. 
Acting in accordance with this, we may protect many ten- 
der plants, simply by placing them out of the reach of the sun’s 
rays during winter. On this principle, a northern exposure 
will, in most cases, be found greatly preferable to a due south 
aspect. After the unparalled rigor of the winter of 1836 — 7, 
peach and other tender fruit trees, planted on the northern sides 
of hills, were found to be but little injured, whilst those on warm 
southern knolls were almost universally destroyed throughout 
the Middle and Eastern States. 
Carnations, monthly roses, and many other plants of similar 
habits, suft’er severely in the more northern parts of the Unit- 
ed States, if left in the open ground without covering; but, as 
many culturists are aware, the trifling shelter of a little straw, 
salt hay, or stems of decayed plants, thrown over them to pro- 
tect them (not from the cold, but from the injurious influence 
of the sun) they are almost as perfectly preserved, as in a more 
temperate climate. 
313 . AUCTARIUM. 
