There is one satisfaction at least in giving knowledge to the ignorant, to those who know their ignorance at least, that they are grateful and humble. You should have my grateful and humble thanks long ago for the favour--the honour--you did me by sending me that Preliminary Dissertation, in which there is so much knowledge, but that I really wished to read it over and over again at some intervals of time, and to have the pleasure of seeing my sister Harriet read it, before I should write to you. She has come to us, and has just been enjoying it, as I knew she would. For my part, I was long in the state of the boa constrictor after a full meal--and I am but just recovering the powers of motion. My mind was so distended by the magnitude, the immensity, of what you put into it! I am afraid that if you had been aware how ignorant I was you would not have sent me this dissertation, because you would have felt that you were throwing away much that I could not understand, and that could be better bestowed on scientific friends capable of judging of what they admire. I can only assure you that you have given me a great deal of pleasure; that you have enlarged my conception of the sublimity of the universe, beyond any ideas I had ever before been enabled to form. The great simplicity of your manner of writing, I may say of your _mind_, which appears in your writing, particularly suits the scientific sublime--which would be destroyed by what is commonly called fine writing. You trust sufficiently to the natural interest of your subject, to the importance of the facts, the beauty of the whole, and the adaptation of the means to the ends, in every part of the immense whole. This reliance upon your reader's feeling along with you, was to me very gratifying. The ornaments of eloquence dressing out a sublime subject are just so many proofs either of bad taste in the orator, or of distrust and contempt of the taste of those whom he is trying thus to captivate.