In 1834 Miss Martineau "qualified," so to speak, for a place among female travellers, by visiting the United States. She spent nearly two years in traversing the territories of the Great Western Republic, and was everywhere received with an enthusiastic welcome. Returning to England in 1836, she recorded her impressions of American society, and her views of American institutions in her "Society in America" and her "Retrospect of Western Travel." These are discriminative and thoughtful, while sufficiently cordial in their praise to satisfy even the most exacting American; and at the time of their appearance these books unquestionably did much to soothe the irritation which Mrs. Trollope's hard hitting had provoked. It is but just, however, to commend the honesty with which she avowed her anti-slavery opinions, which could not then be enunciated without exciting the anger even of the people of the North. It brought upon her no small amount of abuse and contumely, many of those who had previously received her with professed admiration joining in the clamour raised against her by the slave-holders and their partisans. Her literary activity, meanwhile, knew no stint. In 1839 she published "Deerbrook," her best novel, which the critic will always value as a vigorous picture of some aspects of English life. The tone is high and sustained. As for the characters, they are not very strongly individualized; but, on the other hand, the descriptions are clear and forcible, while the interest of the plot is deep and wholesome. John Sterling's criticism of it says:--"It is really very striking, and parts of it are very true and very beautiful. It is not so true or so thoroughly clear and harmonious among delineations of English middle-class gentility as Miss Austen's books, especially as 'Pride and Prejudice,' which I think exquisite." While travelling on the Continent, in the spring of 1838, Miss Martineau was seized with a very serious illness. By slow stages she returned to England, where she settled down near Newcastle-upon-Tyne, to be under the care of her brother-in-law. She resided there for a period of nearly six years. Neither suffering of mind or body, however, was allowed to interfere with her literary work. She gave to the world in 1840 her second novel, "The Hour and the Man," founded on the romantic career of Toussaint L'Ouverture; and composed the admirable series of children's tales, known by the general title of "The Playfellow." These four volumes, "Settlers at Home," "The Picnic," "Feats on the Fiord," and "The Crofton Boys," show her at her very best. They are full of bold and picturesque descriptions, and the story is told with unflagging energy. Her peculiar position suggested a book that has won a well-deserved popularity--"Life in the Sick-room" (1844). Its delicate and judicious reflections, and its pleasing sketches, cannot be read without a touch of sympathy.