Part 3 — Regular Meeting, May 6th, 1867.

President in the Chair.

Thirty-two members present.

Messrs. F. F. Thomas, Silas A. White, B. Smith, M. J. McDonald, Wm. Patten and Philip Prior, were elected Resident Members, and Dr. C. L. Anderson, of Santa Cruz, Cal., Henry Walter Bates, Assistant Secretary Royal Geographical Society of London, Prof. J. H. Balfour, of Edinburgh University, Dr. John Alexander Smith, F.R.S., of Edinburgh, James Haswell, M.A., of the Geological Society of Edinburgh, Capt. J. B. Caldbeck, F.R.G.S., of Singapore, and Sir Roderick I. Murchison, President of the Royal Geographical Society of London, were elected Corresponding Members.

Donations to the Library: Gold and Silver Tables, by L. Garnett; Catalogue of Casts of Fossils for sale by Prof. H. A. Ward, of Rochester University.

The Committee on Field Meetings reported on that of April 20th, near the Twelve-Mile House. Specimens of the fossils collected at the locality visited were exhibited by Mr. Yale, and remarks were made on the position and age of the strata there exposed, by Prof. Whitney, Dr. Cooper and Mr. Stearns. Mr. Lorquin mentioned the species of birds seen and collected during the excursion.

Mr. Stearns presented, in behalf of Mr. Rowell, the following description of a new species of Pisidium, collected during the field excursion to Angel Island:

Description of a New Species of Pisidium.

BY J. ROWELL.

Pisidium angelicum, Rowell.

Shell rounded oval, nearly equilateral, very convex; margin well rounded; beaks very slightly raised and very approximate; surface subgranulate, marked with from one to six very decided striæ or lines of growth; teeth too minute for observation.

Long. (of largest) 2 mill., Lat. 1.5 mill.; Diam. 1 mill.

Habitat: Angel Island.

Of California species, it is most like P. abditum, but differs in its sculpture, its less prominent beaks and its more globular and equilateral form. Most specimens are covered by an exceedingly persistent coat of jet black mud, making examination of them very difficult; but some are perfectly clean.

Mr. Stearns read the following note upon a recent

Exhibition of Parhelia.

On Wednesday, the 17th day of (April) last month, at about 5 o’clock in the afternoon, my attention was attracted towards the heavens by an exhibition of the rather unusual phenomena (unusual in this latitude) known as Parhelia.

The sky in the west at the time was somewhat cloudy, and the atmosphere hazy. I was unable to determine the exact position of the sun, but its altitude was approximately 22° above the horizon; the diameter of the circle or halo was about 24°. A horizontal line, drawn through the sun and projected sufficiently in a northerly and southerly direction to intersect the halo, displayed at each point of intersection, a parhelion or mock sun of very considerable brilliancy, and continued for upwards of half an hour.

A much more extensive display of these phenomena was witnessed by me in the month of April, 1858, while residing near Boston, Massachusetts.

The sun was not far from the zenith, surrounded by a single broad halo, which latter was in turn inclosed by an outer circle of many halos all intersecting with each other and with the central halo—each of the numerous points of intersection gemmed with a parhelion. So extensive was the display, owing to the number of halos and the attendant parhelia, that the whole heavens from the zenith to within apparently 30° of the horizon, seemed covered with brilliant circles or rings, and resplendent with numberless suns. The sky, at the time, was obscured by a haze of considerable density, and a chilling wind was blowing from the south.

Some remarks followed upon sun and moon halos, during which Dr. Gibbons combated the popular notion that halos about the moon were infallible signs of rain. His observations proved that, in some seasons, these signs invariably failed in California, and at the East; he thought no rule could be established on the subject.

Mr. Goodyear presented the following paper in behalf of Professor Silliman:

Notice of New Localities of Diamonds in California.

BY B. SILLIMAN.

Every well-authenticated instance of the existence of the diamond in the United States is of interest, since it serves to enlarge our knowledge of the geographical and geological distribution of this much esteemed gem.

I have the pleasure of exhibiting to the Academy four diamonds, obtained from separate localities in this State. Three of them are crystals, having the form of an icositetrahedron; the other has been cut, and is set as a ring stone.

The First Specimen—Is from Forest Hill, in El Dorado County. Its weight is 0.369 gramme, or 5.673 grains—equal to rather less than 1½ carats. Its color is good, but it has a small cavity and discoloration on one of the solid angles, and it is less symmetrical than the second specimen. This crystal was found at a great depth from the surface in a tunnel run into the auriferous gravel at Forest Hill. I procured this stone from Mr. Tucker, the well-known jeweler.

The Second Specimen—Is from French Corral, in Nevada County. It weighs 0.3375 grammes, or 5.114 grains—equal to about 1⅓ carats. Its form is symmetrical, color slightly yellowish. Its lustre has been dimmed slightly by having been subjected to a red heat as a test of its authenticity. The auto da fé is hardly the test a chemist would select for pure carbon! It is remarkably destitute of flaws. This crystal was washed out from the cement in the deep gravel washings for gold at French Corral, and was found in the sluice boxes. It belongs to Mr. Egbert Judson, of San Francisco, from whom I derive this information.

The Third Specimen—Is smaller and less perfect than either of the preceding. It was found at Fiddletown, in Amador County. It weighs 0.2345 gramme, or 3.619 grains—a little less than one carat. This crystal is distorted, and has several reëntering angles and cavities. Mr. M. W. Belshaw, to whom it belongs, informs me that since 1855, five diamonds have, to his knowledge, been found at Fiddletown, where he then resided; none of them weighing much over one carat. All these specimens were found in a gray cemented gravel underlying a stratum of “lava” or compact volcanic ashes, and were found in searching for gold.

The Fourth Specimen—Is from Cherokee Flat, in Butte County, and has been cut and set in a ring. Mr. Geo. E. Smith, of 605 Montgomery Street, San Francisco, who is an expert in diamonds and owns the specimen exhibited, informs me that he has seen fifteen crystals from this locality, and has authentic advices of at least forty, all of which have been found in deep gravel washings, and are believed to come from a stratum of about three feet thick, forming part of a mass of twenty-five to fifty feet of superincumbent material. When this special stratum of sandy materials is washed, the diamonds have been found. I have taken steps to obtain an authentic crystal from this place, which appears to be the most prolific locality of the diamond yet observed in California.

In the first volume of the Geology of California, page 276, Mr. Rémond is quoted as authority for the existence of diamonds at Volcano. If this locality is distinct from that at Fiddletown, near Volcano, we have at present, five authenticated localities of the diamond in California, from which specimens have been identified by mineralogists.

If a knowledge of the characteristics of this remarkable species was more common among the miners who work in the deep gravel diggings, no doubt this gem would be found to be more abundant and in more numerous places than is now suspected.

San Francisco, May 6th, 1867.

Professor Whitney, in reply to various inquiries made by members, remarked that there were probably some fifteen or twenty different localities in California where diamonds had been found; but these were all of small size, the largest which had come under his notice weighing only 7¼ grains: this was found at French Corral, near San Juan North. It was difficult to give any directions by which miners could infallibly recognize the diamond when they happened to meet with this gem. The crystalline form is very different from that of quartz, which is now, however, much less frequently mistaken for the diamond than it was formerly. Most of the crystals found in California, up to this time, have been twenty-four sided. The fact that the faces of the crystals are usually curved instead of being plane surfaces, is also characteristic of the gem in question. The hardness and specific gravity are also sure guides; but miners rarely have the means of getting at either of these characters accurately. It is commonly believed that the diamond can be struck a heavy blow, on an anvil, without breaking; but this is a mistake, resulting from confounding toughness with hardness. It is extremely doubtful whether washing the gravel for diamonds in California would pay, under any circumstances; and it is believed that such washings are not remunerative anywhere, except when performed by slave or convict labor.

Professor Whitney read a paper on the geological position of coal. The object of this paper was to show how completely the results of modern geological explorations and discoveries had done away with the old idea that valuable beds of coal are confined to any one member of the series of geological formations. The recent investigations of geologists in India, China, Australia, New Zealand, South America, and on the Pacific coast of North America, were noticed and commented on. It was shown that while the important coal fields of Eastern Europe and the Eastern United States are of palæozoic age, those of India, China and Australia, on the other hand, belong to the mesozoic series chiefly, although there are important deposits even as recent as the cainozoic or tertiary. Professor Whitney remarked on the distribution of the principal coal fields of the world into two great groups, on opposite sides of the globe: one of these is of palæozoic, and the other of mesozoic age. He referred particularly to the coal of the Pacific coast of North America, and gave a brief account of its geographical distribution and geological age, noticing particularly the fact that most of the valuable fields of that region belong to the cretaceous series, a geological formation which, in other parts of the world, has been found to be one of the most barren in combustible materials. In conclusion, the importance of coal discoveries in the region between the Rocky Mountains and California to the successful operation of the Pacific Railroad was explained, and the hope expressed that the geological expedition recently set on foot by the General Government, at the head of which is Mr. King, late of the California Survey, might be the means of giving to the world reliable information in regard to the coal resources of that region, of which we now know so little.

Prof. Whitney presented an elaborate paper “On the Natural System of the Igneous Rocks,” by Baron Richthofen; he advised its reference to the Publication Committee, and that it should be made one of the “Memoirs” which the Academy contemplates publishing. It was so referred, and the committee was instructed to report on the feasibility of commencing the publication of a series of quarto Memoirs.

Prof. Whitney exhibited a canine tooth, obtained from the deep gravel deposits at Douglas Flat, near Murphy’s, in Calaveras County; it appears to be different from the teeth of any animal yet found on this coast, either living or fossil. He considered it as probably belonging to the hyæna; if so, this was the first notice of the occurrence of this animal on the American continent.

Dr. Cooper stated that Mr. Ridgeway, the zoölogist appointed to accompany the Government exploration of Russian America, when on that coast, a few years since, had found birds nearly identical with living species in Asia—a fact of much interest, since none of the same species are found on the eastern coast of America. There is here another suggestion of the former intimate relations between Western America and Eastern Asia.