Dear Sir - "A Constant Reader" in the July No., inquires for a little light on the subject of the Buttonwood disease. He shall have that light, alhough he may consider it by far, smaller than a rush-light.

I have long been acquainted with the Buttonwood, and it was with me a favorite tree. I never saw a diseased one in Massachusetts, before May 21st, 1842, and I never have seen a healthy one in Massachusetts since that time. Now for a solution of this mystery, if mystery it may be called. May 20th, 1842, we had a very cold, rainy day, with much sleet, with the wind at north-east and north, which lasted nearly all day, and at sunset the wind hauled round to the north-west, with a clear sky, and at 9 o'clock in the evening it was very cold, with the numerous, stars shining and twinkling as we often see them in December. This state of the weather lasted through the night, and the morning presented appearances which I shall never forget - the earth was frozen hard enough to bear up a man, and the ice was as thick as window glass, and sad to relate, hut the truth must come out, every leaf and Buttonwood bud through the length and breadth of Massachusetts was "as dead as a herring." Now what could the poor Buttonwood tree do in this dilemma? Its leaves and its buds were all gone, but it had life and sap enough to form another crop as large as the first, but how to begin this process was the question.

Nature is never idle, and perhaps she was not altogether prepared for this contingency, and so I should infer from her tardiness in repairing the injury of the 21st of May.

But finally, about the first of July following, young shoots and leaves began to appear - so that the friends of this doomed tree began to hope that all was not lost - and that we should finally see the Buttonwood restored. But that hope is likely to prove fallacious - for new wood, that has only about sixty days to mature in, can hardly get strength and vigor to stand our winters. And consequently, the spring of every succeeding year since that eventful time, finds the Buttonwood without a living bud to start from.

A friend of mine, who is quite a traveler, informed me the other day that the only But-tonwood trees that he had seen, that had not suffered as ours have, were some near the falls of Niagara, and they were in all their glory - having been protected by that eternal spray that always fills the air in their immediate vicinity. Tours respectfully.

Alfred Bailies.

Taunion, July 8, 1851.

[Our correspondent's theory would bo a good one if its application could be confined to Massachusetts. But three years before the falsi day he records, which began the Buttonwood blight in his state, we saw trees entirely killed by it, as far south as Maryland, where no such frost had taken place. From the south, the disease has gradually spread to the north, and we have watched young trees, that stood last year in perfect luxuriance, by the side of diseased old trees, gradually fall victims to the same malady. Wherever the Buttonwood stands in moist ground, there it seems best able to the disease - while in dry, sandy soils, it is a pretty sure victim to it. The cau confident, lies deeper than any matter of climate - and is worthy of the careful tion of vegetable physiologists. Ed.]