A Lecture On Physical Development, and its Relations to Mental and Spiritual Development, delivered before the American Institute of Instruction, at their Twenty-Ninth Annual Meeting, in Norwich, Conn., August 20, 1858. By S.R. Calthrop, of Bridgeport, Conn., Formerly of Trinity College, Cambridge, England. MDCCCLIX. Entered according to Act of Congress, in the year 1858, by Ticknor And Fields, In the Clerk's Office of the District Court of the District of Massachusetts. On motion of G.F. Thayer,--_Voted_, unanimously, That five thousand copies of Mr. Calthrop's Lecture be printed at the expense of the Institute, for gratuitous circulation. LECTURE. Mr. President, Ladies and Gentlemen:-- We have met together to consider the best methods of Educating, that is, drawing out, or developing the Human Nature common to all of us. Truly a subject not easy to be exhausted. For we all of us feel that the Human Nature,--out of whose bosom has flowed all history, all science, all poetry, all art, all life in short,--contains within itself far more than that which has hitherto been manifested through all the periods of its history, though that history dates from the creation of the world, and has already progressed as far as the nineteenth century of the Christian era. Yes! we all of us feel that the land of promise lies far away in the future, that the goal of human history is yet a long way off. A large portion of this assembly consists of those whose business it is to study Human Nature in all its various forms, and who have taken upon themselves the task of developing that nature in the youth of America, in that rising generation whose duty it will be to carry out the nascent projects of reform in every department of human interest, and make the thought of to-day the fact of tomorrow. Some doubtless there are among this number, who by very nature are born Teachers, called to this office, as by a voice from heaven! Men, who in spite of foolish detraction, or yet more foolish patronage, understand the dignity, the true nobility of their calling; who know that the office of the teacher is coëval with the world; and also feel with true prophetic foresight, that the world, fifty years hence, will be very much what its Teachers intend, by God's blessing, to make it. Brothers in a high calling! The speaker, proudly enrolling himself in the number of your noble band, greets you from his heart this day, and invites you to spend a thoughtful hour with him; and to help him, by your best wishes, to unfold in a manner not wholly unworthy of his theme, some small portion of the nature and method of Human Development. Ours is the age of analysis. We begin to see that before we can understand a substance, it is necessary to become acquainted with all its component parts. Thus, then, with regard to Human Nature, we must understand all at least of its grand divisions, before we can comprehend the method of developing it as a whole.