At this time Mrs. Martineau, who was becoming blind, Harriet’s brother, Henry, and an invalid aunt, were all dependent upon Harriet for support. Her anxiety and over-work led to a serious illness. She started for a tour of the Continent after publishing _Deerbrook_, but on reaching Venice, became so ill that she was obliged to return to England. She was taken, in the autumn of 1839, to Tynemouth, where she remained for the next five years under the care of her brother-in-law, a physician named Greenhow. This was a period of great suffering, but her intellectual activity was not suspended. _The Hour and the Man_, a historical romance, appeared in November, 1840; and early in 1841, _The Playfellow_, a series of children’s stories, containing the famous _Crofton Boys_; in 1843, _Life in the Sick-Room_, published anonymously, but generally recognized at once; and numerous stories and articles in aid of various causes. In 1841 she refused, on principle, Lord Melbourne’s offer of a pension of £150 per annum. In 1843 her friends presented her with a testimonial of £1,400. In June of the following year she consented to try mesmeric treatment. In December she was so much better as to be enabled to leave Tynemouth. For the next ten years she enjoyed perfect health. With characteristic enthusiasm, she published the Athenæum, and subsequently in pamphlet form, six _Letters on Mesmerism_, detailing this wonderful cure. This open declaration of her faith in mesmerism led to a breach with Mr. Greenhow. Miss Martineau now purchased land near Ambleside, and took lodgings in the village, during the winter of 1845-6, to superintend the building of a house according to her own plans. Here she wrote her _Forest and Game Law Tales_. In the spring she took possession of her home, called “The Knoll.” After writing a story for the young, _The Billow and the Rock_, she started with some friends for the East, in the autumn of 1846, returning in October, 1847. Her life at “The Knoll” was beneficent and busy. She engaged in farming, on a very small scale, and wrote on the subject a book called _Health, Husbandry and Handicraft_. In _Eastern Life, Past and Present_, published in 1848, Miss Martineau first allowed it to be seen that an important change had taken place in her opinions on theology. This was in some measure due to the influence of Mr. Henry G. Atkinson, with whom she became acquainted during her recovery from her long illness, and who remained her dearest friend until her death. Her next work was _Household Education_, followed, in 1850, by her important HISTORY OF THE THIRTY YEARS’ PEACE. In January, 1851, appeared _Letters on the Laws of Man’s Nature and Development_, the joint production of herself and Mr. Atkinson. In this book her new opinions were distinctly stated. The work was received with horror by the orthodox press. An article on the subject in the Prospective Review, by Dr. James Martineau, caused a breach between the brother and sister.