Part 3 — Regular Meeting, December 18th, 1865.
Reading edition
Dr. Kellogg in the chair.
Six members present.
Dr. Ferdinand Stoliczka, Palæontologist to the Geological Survey of India, was elected a Corresponding Member.
Donations to the Cabinet: One box of shells and two of fishes, collected at Tahiti, by Mr. Andrew Garrett.
The following papers were presented.
Notice of a peculiar Astringent Gum or Coloring Substance in the Cones of the Sequoia gigantea.
BY WILLIAM P. BLAKE.
I am not aware that any notice has yet been taken by scientific chemists of a peculiar substance, apparently a gum, which accompanies the seeds of the great trees, and may be shaken out of the dried cones. About twenty cones yielded me an ounce of the material. It does not adhere to either the seeds or the cone, but appears to have shrunk from both in drying. It falls out in loose broken grains with brilliant conchoidal fractured surfaces, and looks a little like dried blood. The color is purplish-red, nearly black by reflected light, and a brilliant carmine-red by transmitted.
The taste is strongly astringent, and suggests tannin; it is somewhat bitter, and is similar also to that of very strong black tea. It softens and becomes gummy between the teeth. It dissolves completely in water and in ordinary alcohol, giving a brilliant claret-colored solution which gradually darkens by exposure to the air. The addition of carbonate of soda darkens the solution and lime-water turns it black, giving a black scaly precipitate. Dilute sulphuric acid reddens the solution and causes a red precipitate.
It is in many respects similar to the kino of the shops, but has a brighter colored powder and streaks. The kino that I have seen has a brownish-red streak; this substance gives a purplish-red.
The reactions with alkalies and acids in respect to color are similar to those of green redwood boards, which may be stained as dark as rosewood by alkalies and red by acids.
This substance may be found to have some peculiar value in pharmacy, or as a coloring matter for tinctures or wine. I hope that this notice will induce a thorough investigation of its nature and properties. If it proves to be new, I suggest that it shall be known as Sequonin.
Ammonites in the Auriferous Slates of California.
BY WILLIAM P. BLAKE.
Ammonites occur in the gold-bearing slates of Bear Valley, Mariposa County, in addition to belemnites and other fossils already noted. The specimen I have seen is a cast, somewhat distorted by pressure, but apparently similar to the species from the slates on the American River, which I brought to the notice of the academy last year.