Dr. Rush gives a striking instance of the influence of association, which I will relate in his own words: “During the time,” says he, “that I passed in a country school in Cecil county, in Maryland, I often went on a holiday with my schoolmates to see an eagle’s nest, upon the summit of a dead tree in the neighborhood of the school, during the time of the incubation of that bird. The daughter of the farmer in whose field this tree stood, and with whom I became acquainted, married and settled in this city about forty years ago. In our occasional interviews, we now and then spoke of the innocent haunts and rural pleasures of our youth, and, among other things, of the eagle’s nest in her father’s field. A few years ago I was called to visit this woman, in consultation with a young physician, in the lowest stage of a typhus fever. Upon entering the room I caught her eye, and with a cheerful tone of voice said only, _the eagle’s nest_. She seized my hand without being able to speak, and discovered strong emotions of pleasure in her countenance, probably from a sudden association of all her early domestic connections and enjoyments with the words I had uttered. From that time she began to recover. She is now living, and seldom fails, when we meet, to salute me with the echo of _the eagle’s nest_.” It is important in the treatment of disease, to remove all causes which awaken disagreeable associations in the minds of the sick, for they often retard, and sometimes prevent the recovery of the patient. It is as clearly the duty of the physician to detect the causes of such associations, and to remove them if possible, as it is to detect and remove the material causes of any irritation or inflammation. Dr. Rush mentions a case that came under his observation, in which the influence of disagreeable associations hindered the recovery of the patient. “A gentleman in this city,” he says, “contracted a violent and dangerous fever by gunning. After being cured of it, he did not get well. His gun stood in the corner of his room, and being constantly in sight, kept up in his mind the distressing remembrance of his sickness and danger. Upon removing it out of his room he soon recovered.” Some are much more readily affected by mental associations than others. A gentleman in a stage coach was observed to keep his cloak lying by his side, while he was shivering with the cold. He was asked by one of his fellow travellers why he did not put it on. He replied, ‘I have just returned from a voyage, in which I was very sea-sick, and while so I lay with that cloak wrapped around me. Foolish as it may seem, I cannot put it on without renewing the nausea.’