_Fetid Primitive Limestone, &c._--From the vicinity of Williamstown College, through the kindness of Professor Dewey, we have received specimens illustrative of the geology of that region. Among them is limestone from Stockbridge, crystallized in large plates and rhomboids, almost white, and still fetid on being rubbed, which is very different from most fetid limestones, which are dark coloured, and even black, and do not belong to primitive formation. _Molybdena._--In Pettipaug, Saybrook, Connecticut, molybdena occurs. It is mentioned in the Review of Cleaveland's Mineralogy, and is here cited again for the purpose of pointing out its locality more exactly. It is found about half a mile to the E. of the Turnpike leading from Saybrook to Middletown, on the first road on the right hand above the turnpike gate, near the house of the widow Pratt. It is not far from Pettipaug meeting-house, in a northern direction. _Beryl._--In Haddam, Connecticut, are found many beryls, and some of uncommon size; an account of one of the most remarkable localities is contained in the following memorandum from the Rev. Mr. Mather, to whom we are indebted for specimens. "The place in which the beryls are found is in the town of Chatham, about one mile and a half north from Middle-Haddam landing; about half of a mile S. W. of a large hill, on which is the cobalt mine. The rock in which the beryls are contained is granite; the parts of which are very large, especially the felspar and the mica. Large masses of shorl are also found in these rocks. Beryls have also been found in other parts of Middle-Haddam, amongst rocks of the same description. The _greatest_ diameter of the largest beryl is four inches; the _least_ three inches. The beryls are numerous, and of different sizes; though few are less than an inch, or two inches in diameter. The length of the longest beryl is five inches." _Clay._--Near Delhi, New-York, a few rods from the Delaware river, are found beds of clay, of which specimens have been transmitted by Mr. John P. Foote, of New-York. We are of opinion that they are not porcelain clay. _Gypsum._--Cayuga Lake. We are informed by Dr. L. Foot, that the workmen who have excavated about 20 feet on the border of the lake, in gypsum, which is generally of a dark brown, or black colour, when they come to a transparent crystallized piece, call it isinglass, and reject it as worthless: the hint should be remembered by mineralogists, that the specimens may be saved for their cabinets. ASBESTOS IN ANTHRACITE. _Extract of a letter from Dr. I. W. Webster._ BOSTON, 27th Nov. 1818. DEAR SIR,