SIR,-Your letter of February the 18th came to hand on the 1st instant; and the request of the history of my physical habits would have puzzled me not a little, had it not been for the model with which you accompanied it, of Doctor Rush's answer to a similar inquiry. I live so much like other people, that I might refer to ordinary life as a history of my own. Like my friend the Doctor, I have lived temperately, eating very little animal food, and that not as an aliment, so much as a condiment for the vegetables, which constitute my principle diet.