Mr. Wall, to whom our country is indebted for the Hudson River Portfolio, and who resided in the United States for twenty-two years, is here, and is, I should think, quite successful in his profession. Some of his later landscapes are superior to any of his productions that I remember. Among them is a view on Lough Corrib, in which the ruined castle on the island of that lake is a conspicuous object. It is an oil painting, and is a work of great merit. The Dublin Art Union made it their first purchase from the exhibition in which it appeared. Mr. Wall remembers America with much pleasure, and nothing can exceed his kindness to such of the Americans as he meets in Ireland. He took us to the exhibition of the Royal Hibernian Society. Among its pictures is a portrait of a lady by Burton, in water-colors, most surprising for its perfection of execution and expression, its strength of coloring and absolute nature. Burton is a native of Dublin, and is but twenty-five years old. The Irish connoisseurs claim for him the praise of being the first artist in water-colors in the world. He paints with the left hand. There are several other fine things by him in the exhibition. Maclise, another Irish artist, has a picture in the exhibition, representing a dramatic author offering his piece to an actor. The story is told in Gil Blas. It is a miracle of execution, though it has the fault of hardness and too equal a distribution of light. I have no time to speak more at large of this exhibition, and my letter is already too long. This afternoon we sail for Liverpool. Letter XXVI. The Lunatic Asylum at Hanwell. London, _July_ 28, 1845. Since we came to England we have visited the Lunatic Asylum at Hanwell, in the neighborhood of London. It is a large building, divided into numerous apartments, with the plainest accommodations, for the insane poor of the county of Middlesex. It is superintended by Dr. Conolly, who is most admirably fitted for the place he fills, by his great humanity, sagacity, and ingenuity. I put these qualities together as necessary to each other. Mere humanity, without tact and skill, would fail deplorably. The rude and coarse methods of government which consist in severity, are the most obvious ones; they suggest themselves to the dullest minds, and cost nothing but bodily strength to put them in execution; the gentler methods require reflection, knowledge, and dexterity. It is these which Dr. Conolly applies with perfect success. He has taken great pains to make himself acquainted, by personal observation, with the treatment of the insane in different hospitals, not only in England, but on the continent. He found that to be the most efficacious which interferes least with their personal liberty, and on this principle, the truth of which an experience of several years has now confirmed, he founded the system of treatment at Hanwell.