When I reached Jena I was seized by the stirring intellectual life of the place, and I longed to remain there a little time. Eight weeks of the summer half-year's session of 1799 yet remained. My brother wrote to my father that I could fill that time usefully and profitably in Jena, and in consequence of this letter I was permitted to stay. I took lessons in map and plan-drawing, and I devoted all the time I had to the work. At Michaelmas I went home with my brother, and my step-mother observed that I could now fairly say I had passed through the university. But I thought differently; my intelligence and my soul had been stimulated in many ways, and I expressed my wish to my father to be allowed to study finance there, thus returning to my previous career. My father was willing to give his permission if I could tell him how to find the means. I possessed a very small property inherited from my mother, but I thought it would be insufficient. However, after having conferred with my brother, I talked it over with my father. I was still a minor, and therefore had to ask the consent of my trustee to realise my property; but as soon as I had obtained this I went as a student to Jena, in 1799. I was then seventeen years and a half old. A testimonial from my father attesting my capacity for the curriculum procured me matriculation without difficulty. My matriculation certificate called me a student of philosophy, which seemed very strange, because I had set before me as the object of my studies practical knowledge; and as to philosophy, of which I had so often heard, I had formed a very high idea of it. The word made a great impression upon my dreamy, easily-excited, and receptive nature. Although the impression disappeared almost as soon as conceived, it gave, however, higher and unexpected relations to my studies. The lectures I heard were only those which promised to be useful in the career I had now again embraced. I heard lectures on applied mathematics, arithmetic, algebra, geometry, mineralogy, botany, natural history, physics, chemistry, accounts, cultivation of forest trees and management of forests, architecture, house-building, and land-surveying. I continued topographical drawing. I heard nothing purely theoretical except mathematics; and of philosophical teaching and thought I learnt only so much as the intercourse of university life brought with it; but it was precisely through this intercourse that I received in various ways a many-sided intellectual impulse. I usually grasped what had been taught; the more thoroughly since, through my previous life, I had become well acquainted with the principal subjects, and already knew their relation to practical work.