Effects of Frost on Plants. 23 
rophyll, the nucleus of éells, elementary fibre, amylaestios mat- 
ter, raphides, nor the various crystals contained ; in vegetable tis- 
sue, undergo any alteration, unless perhaps in the case of amy- 
laviaiets matter, which in some cases is converted into sugar, no 
doubt in consequence of the action of some acid formed by. the 
decomposition of the organic parts. 3. That the action of frost 
operates separately upon each individual elementary organ, so 
that a frozen plant contains as many icicles as there are cavities 
containing fluid ; the dilatation thus produced, not being sufficient 
to burst the ides ofthe cavities. 4. That such dilatation is prin- 
cipally owing to the separation of the air contained in the water. 
5. That this disengagement of air by [from?] water, during the act 
of congelation, is the most injurious of all the phenomena attendant 
upon freezing ; introducing gaseous matter into organs not inten- 
ded to elaborate it, and bringing about the first stage in a decom- 
position of the sap and the matters it precipitates; so that-with a 
thaw, commences a new chemical action destructive of vegeta- 
ble life. mre That the expansion of the cells and aquiferous or- 
gans, a great quantity of water into the air-cells and air- 
vessels, so ‘that the apparatus intended to convey liquid only, con- 
tains water and air, while that which is naturally a vehicle for air 
conveys water. Such an inversion of functions must necessarily 
be destructive to vegetable life; even if death were not produced 
in frozen plants by the déeonposition of their juices, the loss of 
their erase and the chemical disturbance of all their con- 
tents. 
-“ Professor Moreen ’s observations were made upon various desi 
frozen in the spring of the present year, having been exposed toa 
rature of — 4° to +9° Fahrenheit. One of his statements: 
I give in his own words. - ‘In the parenchyma a of many plants, 
and especially in that of succulent fruits, it is easy to. ascertain 
what modifications are caused by frost in the internal organs of 
plants. Ifa frozen apple is opened, it is obvious that the ice is 
not a continuous mass, but that it is a collection of a multitude of 
little microscopical icicles. Under the microscope the fact be- 
comes evident. e know how excessively hard some fruits be- 
come when frozen by this mosaic of icicles, especially pears. If 
we thaw them, it is seen that on the instant a multitude of air- 
bubbles are extricated from the juice of the fruit, and that this 
juice has then acquired new chemical qualities. 1 wished to as-. 
