The science of agriculture rests on experience; and nothing else should be required or expected from it but that which appertains to a practical scie… - Albrecht Daniel Thaer

It was now, I thought, high time to think earnestly of getting into good practice as a physician. I followed, in order to effect this, my own method; I cared not for criticism; good luck attended me; I was successful in many cases given up by others as hopeless. My father watched me now closely, but let me have free sway; he felt great pleasure at my success, and would now and then say, "Well done, my boy;" but nevertheless entreated of me not to offend a certain great personage; which, however, I frankly confessed I had already done, not caring much about it, as it was my intention not to stay in Celle. I wanted a greater sphere of action. My father's weakness and infirmity increased daily, which prevented him from visiting his patients, and determined him to give up altogether his practice, and to retire from a profession in which, during many years, he had so nobly done his duty; he informed his patients of it, telling them that they were perfectly free and at liberty to take the advice of his son, or any other physician, thereby insinuating, that in their choice they must not suffer themselves to be influenced by their feelings of friendship and regard towards him. Almost all his patients honoured me with their confidence.

Agriculture is the art of deriving from the earth the most valuable organic productions. He who exercises this art, seeks to obtain profit by causing to grow, and by using, its animal and vegetable productions. The more considerable the gain derived, therefore, the better is the object accomplished. The most perfect agriculture is, evidently, that which produces, by the application of labour, the largest and the most permanent profit in comparison with the means employed. Systematic agriculture ought, then, to teach us all the circumstances by means of which we may derive the most considerable profit by the practice of the art.

I was now in my sixteenth year, and for the first time it occurred to me that, although conversant with most of the modern languages, I did not understand a word of Latin, and thought the knowledge of this language indispensable to my future prospects in life. I spoke to Rector Steffens, and got permission of my father to leave school entirely, and devote my whole time to the study of Latin. In less than twelve months I was completely master of a language which is often the torment of boys from their sixth to their twentieth years, and still remain ignorant of it. Since then I have written several pamphlets in Latin, which were admired; and in my Discourses were generally delivered in that language. Doctor Taube, physician to the king, gave me lessons in natural history, botany, and anatomy; I bade farewell to philosophy and belles lettres, and began in earnest, and with great perseverance, to study physics; but still I was in bad odour amongst many of the learned, and it was said, when they heard of my progress, that henceforth they should not despair of making something of the most stupid of pupils.