Among other plants observed about our encampment, was the wild liquorice, (glycyrhiza lepidota, N.) which is believed to be the plant mentioned by Sir A. Mackenzie,[97] which is used as food by the savages of the north-west. The root is large and long, spreading horizontally to a great distance. In taste it bears a very slight resemblance to the liquorice of the shops, but is bitter and nauseous. The leaves are frequently covered with a viscid exudation. [97] For sketch of Sir Alexander Mackenzie, see Franchère's _Narrative_, in our volume vi, note 4.—ED. We were prevented from continuing our astronomical observations, in the afternoon, the weather becoming cloudy, and at evening a thunder-storm commenced, which continued with short intermissions during the night. The lightning exhibited an incessant glare, and peals of thunder which seemed to shake the earth to its centre, followed each other in rapid succession. On Monday the 19th, we moved on, and ascending the Platte about thirty miles, arrived in the evening at a place where the hills on the north side close in, quite to the bed of the river. On both sides they became more broken and elevated, and on the north, they approached so near to the bed of the Platte, that we were under the necessity of travelling across them. We were glad, however, of any change of scene. The monotony of a vast unbroken plain, like that in which we had now travelled nearly one hundred and fifty miles, is little less tiresome to the eye, and fatiguing to the spirit, than the dreary solitude of the ocean.[98] [98] The Sand Hills begin at about the hundredth meridian, which crosses the Platte in western Dawson County.—ED.