Our readers know that we have furnished innumerable evidences that the juices of plants do not freeze, and the plants so frozen continue to live. And how strangely some of our friends quite distinguished in science persist in ignoring these facts. One of them, President Clark, when the observations referred to were brought to his notice, deeming them of no further importance than the short reply, "Of course the sap freezes." In spite, however, of these contemptuous expressions, we hope to be pardoned for continuing to place on record such facts as seem to prove the point.

In the Gardener's Chronicle of March 25th a correspondent, B. Piffard, records an experiment made with the juice of the cabbage leaf. Two glasses, one filled with pure water, the other with water and the juice of cabbage leaves, were placed side by side in a frosty atmosphere. At the point where the pure water froze the solution of cabbage juice remained liquid. And he goes on to infer, as we have often done, "that if a plant survive a degree of cold at which other plants perish, their preservation is attributable to the non-congelation of the sap." Does it not occur to the reader that something more than "Of course not" is required from President Clark and our other friends to set aside such reasoning as this?

W. B. says: "I would like to take the Editor of the Gardener's Monthly out in Massachusetts when the mercury indicates 20° below zero, and help cut down some trees frozen so as to be brittle." [Our correspondents forget what has been said of this subject in our past pages. We have seen plenty of frozen wood, without going to Massachusetts to find it. There is no reason that we know of why liquid that has not been prepared for plant life should not freeze. Trees in these parts often freeze so that they split by frost. But this is from the moisture in the dead wood. What is called heart wood in plants can absorb moisture. In winter there is not much in this wood; sometimes there is, and if it freezes, it expands. In most trees the living cells are those in the few outer woody circles. It is these living cells which prepare their peculiar material, the leaves at certain seasons assisting, and it is these living cells that do not freeze; or, when they do freeze, they die.- Ed. G. M.]