The President of the British Association, St the late meeting in Dublin, introduced the following extraordinarily beautiful illustration: "* * In order thai the date palm should ripen its fruit, the mean temperature of the place must exceed 70 Fahrenheit; and, on the other hand, the vine cannot be cultivated successfully when the temperature is 72P, or upwards. Hence the mean temperature of any one place at which these two plants flourished and bore fruit, lie between these narrow limits - i. e., could not differ from 71° Fahr. by more than a single degree. Now, from the Bible, we learn that both plants were simultaneously cultivated in the central valleys of Palestine, in the time of Moses; and its then temperature is thus definitely determined. It is the same at the present time-; so that the mean temperature of this portion of the globe has not sensibly altered in the course of thirty-three centuries!"

Three New Books, of much interest to our readers, have been just published. Latin Blodget's Climatology of the Untied States, admirably produced from the press of Lippincott & Co., of Philadelphia, will command the attention of the student no less than of the general reader. Statistics have prepared the way for this book, and Mr. Blodget seems to have been the right man to step in and tell us the results. Our pages, hereafter, will benefit by the work. It is a large octavo, of 534 pages, for four dollars.

Downing's Fruits and Fruit-Trees of America revised and corrected by Charles Downing. has at last been published by Wiley and Halsted, New York. It is much enlarged, contain* ing 755 pages, and we need scarcely say that it dears up many confused points with as great accuracy as was possible from the combined information of our best Pomologists; introduces the new fruits cautiously and carefully; and is altogether the vade meoum of this country - indispensable to the fruit grower, and invaluable to the amateur. so far as we have examined the work, ft is eminently satisfactory. The modesty of the reviser is a beautiful feature, and when we consider the amount of labor it has involved, and that lot no selfish ends (the proceeds of the copyright being the property of the relict of the late A. J. Downing), no one can look upon the book without a feeling of admiration, and its purchase as a double pleasure. We regret that the index, on which great care appeare to have been exercised, is yet somewhat imperfect.

For instance, after examining these fat the Lenoir, Long, Deverouz, and Thurmond Grapes, and not finding any-refreance to them, we discover, at page 340, the following in the text: -