A very interesting series of etchings from the pencil of Mr. J. W. Ehninger, a young New York artist, has just appeared. They illustrate Irving's Dolph Heyliger, and are full of the humor of that charming Dutch story. Mr. Ehninger is a pupil of the Düsseldorf school, and has but just left its severe training. His style shows the conscientious faithfulness which is inculcated there, as one of the first requisites of a true artist; he has very happy conceptions of character, and seems to be thoroughly imbued with the spirit of the Knickerbocker times. In illustrating them he can not but achieve desirable reputation.

An informal meeting of a large number of the members and associates of the Academy of Design took place early in the last month. Its object was to devise measures to make the Academy a more efficient means of advancing the Art. It was determined, among other things, that lectures should be delivered upon Painting, and the various subjects connected with it. We have heard the Rev. Dr. Bethune named as likely to be the first lecturer. He could hardly fail to interest and instruct both the Members of the Academy, and the public generally, upon the subjects naturally falling within the scope of the first of such a series of lectures. It is gratifying to see that the members of the Academy are at last beginning to awake to the consciousness of its inefficiency, and we trust that some benefit may accrue to Art from their action.

Leutze's great picture of Washington Crossing the Delaware, a grand subject on which he had been engaged nearly three years, has been destroyed by fire, or rather in consequence of fire, as we learn by a letter from the artist himself, dated Düsseldorf, Nov. 10th. It is gratifying, for the artist's sake, to know that the picture was fully insured; but Insurance Companies, although very good protectors against pecuniary loss, can not reproduce works of genius or make up for their loss.

Mr. Hawthorne, whose Scarlet Letter showed such rare ability in the portrayal of the hidden workings of the heart, has a new work nearly finished, called The House of Seven Gables; it will be eagerly sought for, and we trust may prove as admirable a performance as the first-named book.

The purchase of the Greek Slave for distribution has brought the Western Art Union three thousand subscribers this year. It is an increase of nearly one hundred per cent upon the subscriptions of last year, but is hardly enough to warrant the addition of many other prizes to the great one.

Jenny Lind continues her triumphant progress through the country, delighting the world and doing good. Each place which she visits gets up an excitement, which if it be not equal to that at New York, is at least the result of a conscientious endeavor to accomplish the most which can be achieved with the means at command. Her four concerts in Baltimore are said to have produced forty thousand dollars, which is even more in proportion to the wealth and size of the place than the average receipts at her concerts in New York.

It is stated that the existence of a third ring around the planet Saturn was discovered on the night of Nov. 15th, by the astronomers at the Cambridge Observatory. It is within the two others, and therefore its distance from the body of Saturn must be small. It will be remembered that the eighth satellite of this planet was also discovered at Cambridge, by Mr. Bond, about two years since.

Mr. Junius Smith, who has been for some years very zealously engaged in introducing the culture of the tea plant into the United States, gives it as the result of his experiments that the heat of summer is far more to be feared for the tea plant, than the cold of winter, and requires more watchful care. In his field at Greenville, S. C., he has shaded every young plant put out the first week in June, and so long as he continued to do so, did not lose a single plant by the heat of the sun. The young tea-plants from nuts planted on the 5th of June last, and those from China set out about the same time, and most of them still very small, do not appear to have sustained the slightest injury, but are as fresh and green without any covering or protection, as they were in September. He thinks it not at all unlikely that the cultivation of the plant will become general in New England before it does in the Southern States.

Mr. Darley, whose outlines of Rip Van Winkle, and Sleepy Hollow, published by the Art Union, won him so much reputation in Europe as well as here, is about to publish a series of outline illustrations of Margaret, an American novel, said to be of great interest. We had some time since the pleasure of seeing the drawings for these illustrations, and will venture to say that in truthfulness of expression and accuracy of outline they are beyond any American works of their kind, and surpassed by none we know of which have appeared in Europe, we will not even except those of Retzsch.

The Art-Union Bulletin is our authority for stating that Mr. Darley has also engaged to furnish, to a print publisher in this city, twelve designs of large size, representing prominent scenes in American history. They are to be sketches in chiaroscuro, which will afterward be engraved in mezzotint. The first of these designs represents The Massacre of Wyoming. The point of time chosen by the artist, is the first demonstration made by the savages against the settlement, on the day preceding the general slaughter. A letter to the Tribune states that Mr. Healy, one of our best portrait painters, is hard at work on the figures of the former two great rivals, Mr. Webster and Mr. Calhoun. That of Mr. Calhoun is simply a full-length portrait, representing him as taking his leave of the Senate; it is for the Charleston authorities. The accessories of the painting are unimportant. That of Mr. Webster, however, gives us a large section of the Senate chamber, galleries included, and about one hundred and fifty figures or portraits, all after life. It is yet in outline. Boston will possess this valuable work of art, and almost living history of the celebrated speech on the Constitution.