It is not uncommon to find the memory retentive on some subjects, yet extremely defective on others. The remarkable powers of some are limited to dates and names. A lady with whom we were acquainted could tell the number of stairs contained in each flight in the houses of all her acquaintance, but her memory was not particularly retentive in any thing else. In the notice of the death of Miss Addison, daughter of the celebrated Addison, which took place in 1797, it is stated, that "she inherited her father's memory, but none of the discriminating powers of his understanding; with the retentive faculties of Jedediah Buxton, she was a perfect imbecile. She could go on in any part of her father's works, and repeat the whole, but was incapable of speaking or writing an intelligible sentence." Cases of occasional forgetfulness on matters of interest to the mind are among the strange caprices of memory. When Dr. Priestley was preparing the dissertations prefixed to his "Harmony of the Gospels," he had taken great pains to inform himself on a subject which had been under discussion, relative to the Jewish passover. He transcribed the result of his researches, and laid the paper aside. His attention being called to something else, a fortnight elapsed before the subject again occurred to his mind. The same pains were taken which he had bestowed on it before. The fruits of his labor were again written out. So completely had he forgotten that he had before copied out exactly the same paragraphs and reflections, that it was only when he found the papers on which he had transcribed them that it was recalled to his recollection. At times he has read his own published writings without recognizing them. John Hunter's memory once failed him. When he was in the house of a friend, he totally forgot where he was, in whose house, in what room, or in what street, or where he lived himself. He was conscious of this failure, and tried to restore his recollection by looking out of the window to ascertain where he was, but to no purpose. After some time, recollection gradually returned. It is well known that a young man of great ability, and for whom his friends looked for the most brilliant success, totally forgot what he had been about to say, when making his first, and, as it proved, his only parliamentary speech. He tried to resume the thread of his argument, but all was a cheerless blank--he came to a dead stop; and thus his parliamentary career ended: he never attempted to address the house again. An actor, who was performing in a play which had a great run, all at once forgot a speech which he had to make. "How," said he, when he got behind the scenes, and offered, as he thought, a very sufficient excuse, "how could it be expected that I should remember it forever. Haven't I repeated it every night for the last thirty nights!"