Though the main object of this summer tour was to work out the geological problem which had been assigned to him in Sutherlandshire, he sketched a most circuitous route, partly for the sake of showing Mrs. Murchison something more of the Highlands than she had yet seen, and partly with the view of putting to use his new acquirements in geology; so that after reaching Edinburgh, and having its geology expounded to him by Jameson, instead of striking north at once, he turned westwards to the island of Arran, and spent many weeks among the western islands from the Firth of Clyde to the north of Skye. The hills of his native country had now acquired an interest for him which they never possessed even in the days when they drew him off in eager pursuit of grouse and black cock. At every halt his first anxiety was to know what the rocks of the place might be, and how far he could identify their geological position. In Arran he filled his notebook with observations and queries about granite, red sandstone, limestone, and other puzzling matters, on which his previous experience in fieldwork in the south of England and in Yorkshire could throw no light, and for the elucidation of which he wisely resolved to secure, at some future time, the guidance and co-operation of an older geologist than himself. It was in the fulfilment of this resolution that Sedgwick and he first became fellow-workers in the field. In the wildest of the western islands he and his wife did excellent work in collecting fossils, and thereby obtaining materials for making more detailed comparison between the secondary rocks of the west of Scotland and those of England than had been attempted by Dr. Macculloch. The actual fossil-hunting was mainly done by Mrs. Murchison, after whom one of the shells (_Ammonites Murchisoniæ_) was named by Sowerby, while her husband climbed the cliffs and trudged over the moors and crags, to make out the order of succession among the secondary strata. But the tour was not merely geological; many a halt and detour were made to get a good view of some fine scenery, or to make yet another sketch. Friends and highland cousins, too, were plentifully scattered along the route, so that the travellers had ample experience of the hearty hospitality of those regions. An occasional shot at grouse or deer, varied the monotony of the hammering; but even when stalking, Murchison could not keep his eyes from the rocks. Amid the jottings of his sport he had facts to chronicle about the gneiss or porphyry or sandstone through which the sport had led him. This characteristic, traceable even at this early period of his life, remained prominent up to the last autumn of his life in which he was able to wield a gun or hammer.