Like the rocks of Whaley Bridge, Kinder Scout, Greenfield, and Seal Bark, those of the Hebden valley consist of millstone-grit, alternating with shale, the latter cropping out chiefly along the course of the river. It was among these shales, though perhaps more particularly in portions laid bare during the construction of the line along the main or Todmorden valley, that Samuel Gibson, the once celebrated blacksmith-naturalist of Hebden Bridge, pursued his researches in connection with fossil shells, as described in the first volume of the _Transactions of the Manchester Geological Society_ (1841). His work is said, in the volume in question, to have been carried on in "High Green Wood," and as regards the common use of this name, correctly so, as it is applied very generally to the entire valley, or from the village up to the insulated rocks. Properly, however, it denotes only a small portion near the latter. Gibson, a man wholly self-taught, and who kept to his anvil till nearly the time of his death, in the spring of 1849, possessed a vast amount of knowledge of almost every department of natural history. A considerable portion of his collection, comprising a cabinet of seeds of British plants, ferns, lichens, Marchantias, shells, and insects, was purchased, after his decease, for the Peel Park Museum. Another portion went to the museum once existing in Peter-street. The herbarium of flowering plants, valued at £75, went into the hands of Mr. Mark Philips. Most men suffer from some kind of constitutional malady. Poor Gibson laboured under an infirmity of temper which constantly brought him into collision with his fellow-students. He always meant well, as proved in his last famous battle over the _Carex paradoxa_; and probably had his life been a less lonely one the roughness would have got smoothened, and he would have been as friendly with all other men as with the writer of this little notice, which is intended rather to preserve the memory of a singularly acute and industrious observer of nature, working single-handed, in the face of enormous difficulties, than to imply the least reflection on his tendency to warfare. The distance of Gibson's home, twenty-four miles of coach-road, prevented his often coming to Manchester; but no man was ever more welcome. How different some of those he came among! As for old Crozier, whose name we have already mentioned two or three times, and whose work was so largely identified with White Moss, Boggart-hole Clough, and Bamford-wood, in temper and disposition he was Gibson's completest antithesis. No man has ever done more, in his own circle, to foster and diffuse the love of nature and of natural science--accomplishing this, as Crozier did, not so much through the variety and exactitude of his knowledge, as through the urbanity of his manner. Few are now living who remember Crozier; it may be allowed, therefore, to repeat what we said of him in 1858,