However, he soon found an opportunity to engage in teaching again, and embraced it eagerly. But here he was destined to disappointment. His pulmonary tendencies, which had for ten years been increasing upon him, aggravated, no doubt, by hard study and improper diet of the preceding winter, now became very alarming. Beside a severe cough and great emaciation, he was followed by hectic fever, and the most exhausting and discouraging perspirations. He fought bravely to the last moment, but was finally compelled to quit the field, and endeavor to regain his health. For a time, he followed the soundest medical advice he could obtain; kept quiet, took a little medicine, ate nutritious food, and when his strength would permit, breathed pure air. This course was at length changed, for one of greater activity and less stimulus. He abandoned medicine, adopted for a time the "starvation system," or nearly that, and threw himself, by such aids as he could obtain, into the fields and woods, and wandered among the hills and mountains. In autumn, he was able to perform light horticultural labors, a few hours of the day, and to ride on horseback. For six months he rode almost daily in company with a physician; at the end of which period he commenced the practice of medicine, in the place where he had last labored, and where he was born. After continuing in the practice a few years, and his health seeming to be restored, he ventured to return again to the work dearer to him than any other--that of teaching. But his labors seemed again to be slowly undermining his health, and, fearful of a relapse of the pulmonary tendencies, he abandoned for a time all hope of teaching permanently. The following year, he became connected with Rev. William C. Woodbridge, and continued to labor in the cause of education for several successive years. In Jan. 1833, he removed to Boston, and during the winter had a severe attack of bleeding at the lungs, and other dangerous symptoms. These, however, passed away; and the great change which, in 1830, had been made in his physical habits, seemed to be working one equally great in his constitutional tendencies. For while his labors were constant and often severe, there was a steady gain in health. The strength and elasticity of youth returned, and, to use his own words it was with him, now, "morning all day." The effects of an unfavorable climate, which he had feared, were apparently held in check, and he sometimes said that "Obedience gave him command over climate, in a great degree." Yet, during all these years when his health was apparently most firm, it was kept in this condition only by a rigid obedience to the laws of life and health, as he understood and expounded them. His precepts and practice were in harmony.