This section is from the book "The Gardener's Monthly And Horticulturist V26", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
"A. J. M.," Berlin Heights, Ohio, says: "I see by the Country Gentleman, March 13, Prof. Burrill, of Illinois, says the sap of the apple tree does not freeze till 120 degrees below zero! I have seen tender things with bark frozen loose at zero, or somewhat protected".
[There is no better illustration of the confusion of ideas that prevails about the " freezing of sap " than the above paragraph affords. Some contend that sap does not freeze at all, others that it does whenever the thermometer falls below freezing point. Then there are some who believe that the sap in a tree may become solid ice, and that it may thaw subsequently, and the tree go on again with its functions. Others, who believe that when once a tree has its liquids congealed by frosts, life departs.
Now, before one can make anything out of the remark attributed to Professor Burrill, it would be necessary to know to which of these classes he would be referred. Unless he believes that the tree is killed when the liquids freeze, how are we to know that the liquids freeze at 12° below zero.
Our own views of the question are so well known that they need not be repeated here. - Ed. G. M].