Dear Sir,
In examining some masses of the anthracite from Rhode Island, one piece attracted my attention, from the waved structure of the lamellæ into which it separated. The fragments of this were wedge-shaped, and I found the space between some of the laminæ filled up by a fibrous, silky substance, which induced me to break up other masses, in one of which I discovered an abundance of amianthus; the filaments are of a light-green colour in some parts of the mass—in others presenting different shades of brown. With a microscope, I found the fibres intermixed with the anthracite; or forming thin layers, and these sometimes parallel to, at others crossing, in different directions, the course of the laminæ. How far the presence of this mineral may influence the ignition or combustion of the coal, is a question, perhaps, worth determining. Should my engagements permit, I shall make further examination, and inform you. In the mean time, the notice of this fact may call the attention of some of your readers to the subject. At any rate, this substance has, I believe, never before been noticed in connexion with anthracite, and is highly interesting in a geological point of view.
REMARKS.
We have been familiar with the Rhode Island anthracite, and with the formation of rocks in which it is found; and, long since, observed the fact mentioned by Dr. Webster. The asbestos often is in the form of the most delicate amianthus, frequently blended also with the slate rocks, which form the roof and pavement of this coal. A specimen now lies before us, in which a complete vein of this amianthus, with fibres nearly two inches in length, connects and pervades a mass of slate, supposed to be of the transition class.
Similar facts are mentioned also by Dr. Meade, in his account of the Rhode Island coal.
RED PYROXENE AUGITE.
Extract of a letter to the Editor, from Dr. H. H. Hayden of Baltimore.