I spoke in my last of the change caused in the aspect of the country by cultivation. Now and then, however, you meet with views which seem to have lost nothing of their original beauty. One such we stopped to look at from an eminence in a broad prairie in Lee county, between Knox Grove and Pawpaw Grove. The road passes directly over the eminence, which is round and regular in form, with a small level on the summit, and bears the name of the Mound. On each side the view extends to a prodigious distance; the prairies sink into basins of immense breadth and rise into swells of vast extent; dark groves stand in the light-green waste of grass, and a dim blue border, apparently of distant woods, encircles the horizon. To give a pastoral air to the scene, large herds of cattle were grazing at no great distance from us. I mentioned in my last letter that the wheat crop of northern Illinois has partially failed this year. But this is not the greatest calamity which has befallen this part of the country. The season is uncommonly sickly. We passed the first night of our journey at Pawpaw Grove—so named from the number of pawpaw-trees which grow in it, but which here scarcely find the summer long enough to perfect their fruit. The place has not had the reputation of being unhealthy, but now there was scarce a family in the neighborhood in which one or more was not ill with an intermittent or a bilious fever. At the inn where we stopped, the landlady, a stout Pennsylvania woman, was just so far recovered as to be able, as she informed us, "to poke about;" and her daughter, a strapping lass, went out to pass the night at the bedside of one of the numerous sick neighbors. The sickness was ascribed by the settlers to the extremely dry and hot weather following a rainy June. At almost every place where we stopped we heard similar accounts. Pale and hollow-eyed people were lounging about. "Is the place unhealthy," I asked one of them. "_I_ reckon so," he answered; and his looks showed that he had sufficient reason. At Aurora, where we passed the second night, a busy little village, with mills and manufactories, on the Fox River, which here rushes swiftly over a stony bed, they confessed to the fever and ague. At Naperville, pleasantly situated among numerous groves and little prairies swelling into hills, we heard that the season was the most sickly the inhabitants had known. Here, at Chicago, which boasts, and with good reason, I believe, of its healthy site, dysenteries and bilious attacks are just now very common, with occasional cases of fever.