Frost or Fire?
How does it come about that the frost has effects which suggest rather fire. than cold ? Green leaves look black— as indeed do the centres of the killed blossom—as if they had been scorched. And the appearance is not without justification. The frost crystals form in the intercellular spaces and subsequently the cell walls burst and break down, not while the frost is upon them, but at a later hour soon after the sun reaches them. They exhale water and cannot suck it in again through the cell walls. For the second time in my experience I saw this fact persuasively illustrated. An expert gardener in Hereford watered his potatoei through a fine hose early in the morning before the sun reached them in any force. Being- of a scientific turn he left some roots unwatered. The next morning the different fates of the two leapt to the eye. All the unwatered plants were browned, .blackened or cut clean down. The watered plants were very nearly, though not quite, unscathed. Unfortu- nately such treatment cannot be meted out to blossom whether on the ground or on the tree. It is a melancholy task to go round and lift blossom after blossom to see the centre of the-flower quite black, though the petals are scarcely affected. The froSt was heavy enough so to blacken some unopened buds and to shrivel- the -stalk even of set fruit
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