humilis, L. (142, 302, 339), and the interesting Agdestis clematidea, Moç. & Sesse (146), of which Berlandier's no. 2367 is the female plant, in fruit. Concerning this genus, see Grisebach, Erlaut. Pl. Amer. Trop. p. 4.

Anredera scandens, Moq. (227), and the following Amarantacea (all common weeds, except the first), Telanthera gracilis, Moq. (287); Alternanthera Achyrantha, R. Br. (179); Iresine celosioides, L. (221); Gomphrena globosa, L. (140); Cyathula achyranthoides, Moq. (254); Achyranthes aspera, L. (359); Chamissoa altissima, H. B. K.; Amarantus paniculatus, L. (283).

The single Laurineous plant in the collection is an interesting and little-known one, viz. Misanteca capitata, Schlecht., with flowers and fruit. It well accords with the published description, except that the cupule of the fruit (which is said to be red, and is probably somewhat fleshy when fresh) is not sulcate, and its border is evenly truncate. The fruit itself seems to be a nut rather than a berry, as may also be inferred from the fact that the collector took the tree for an Oak. It is "a tall tree" (375).

The Euphorbiacea are Acalypha alopecuroides, Jacq. (304); an undetermined Croton (192), C. Eleuteria, L., or near it (199, 243), and the male of C. trichocarpum, Torr. Bot. Mex. Bound., p. 196 (167); Dalechampia scandens, L. (158), and another species allied to D. convolvuloides (348), an Euphorbia near to or identical with E. hexagona, Nutt. (157); E. pilulifera, L. (133); and E. dioica, H. B. K., which is E. adenoptera, Bertol., and, according to Dr. Engelmann, E. anceps, Benth., and Anisophyllum densiflorum of Klotzsch and Gärke, in their recent dissection of the natural Linnæan genus (251).

The Urticaceae are Pilea microphylla, Liebm. (P. muscosa, Lindl., &c. 172); an undetermined Ficus (332); Dorstenia Contrayerva, L. (198), and D. excentrica, Moricand (123); the interesting Castilloa elastica, Cerv. (371); and a Celtis (nearly of the section Mertensia, H. B. K.) which appears to be new, but which I am unwilling now to describe as such (321).

There is a common Callitriche (143); an Artanthe (234); Peperomia Berlandieri, Miq. (358); a Salix (178); Myrica Xalapensis, H. B. K. (204); and a Quercus, the same as Berlandier's no. 2194 (346).

The Endogenæ of the collection are very few, consisting of the inflorescence of a "Palm, 30 or 40 feet high, with flabelliform leaves, used for covering roofs, and a sweet, edible fruit," apparently the same

as Berlandier's 3207, probably Sabal umbraculifera, Mart. (314); two Cannacea (274, 282); Bomarea hirtella, Herb. (205); a Tillandsia (276) and a Bromelia? (372); Pontederia sagittata, Presl. (277); Smilax mollis, H. B. K. (325), S. platycentra, Schlecht.? but nearly unarmed (244, 336, 337), and another, perhaps the male of S. glaucocarpa, Schlecht. (363); a Tradescantia (275); Eleocharis geniculata, L. (208); Panicum divaricatum, L. (281) and P. hirtellum, L. (266). The Ferns, separately numbered, are, Polypodium incanum, Sw. (8), P. repens, Sw. (16), P. decumanum, Willd. (15), and P. lycopodioides, L. (9); Gymnogramme (Hemionitis) palmata, L. (6); Cheilanthes elongata, Willd. (19); Adiantum Chilense, var. hirsutum, Hook. (11), and A. tenerum, Sw. (17); a variety of Pteris aquilina, L., nearly P. caudata (4), and P. grandifolia, L. (5); Asplenium pumilum, Sw. (10); Phegopteris tetragona, Mettenius (2, 13, 14); Aspidium trifoliatum, Sw. (1); Anemia adiantifolia, Sw. (3); and Lygodium Mexicanum, Presl. (7).

5. Note on the Genus Graphephorum, Desv., and its Synonymy. By ASA GRAY.

This communication announced the discovery by Dr. Charles Pickering, in August last, at the Falls of the Riviere du Loup, in Lower Canada, of the " Aira melicoides" of Michaux, on which Desvaux and Beauvois founded the genus Graphephorum; also that the Dupontia Cooleyi, of the second edition of Gray's Manual of the Botany of the Northern United States, proves to be a large variety of the same species. Carrying out the view indicated in the Manual, Dr. Gray proposes to dispose the genus so extended as to include Dupontia, R. Br., Scolochloa of Link, and Arctophila of Ruprecht - as follows:

Genus GRAPHEPHORUM, Desv., Beauv.

Graphephorum, "Desv.," Beauv. Agrost. p. 76, t. 15, f. 8 (1812); "Desv. Jour. Bot. ann. 1813, p. 71"; Kunth, Enum. 1, p. 250, & Suppl. p. 193, t. 14, f. 9 (pistillum et squamulæ) G. melicoides, Desv. (Aira melicoides, Michx.). Dupontia, R Br. App. Voy. Parry, p. 190 (1824) = D. Fischeri, R. Br. Scolochloa, Link, Hort. Berol. Descr. 1, p. 136 (1827) = S. festucacea, Link (Arun

do festucacea, Willd. Festuca borealis, Mert. & Koch. F. arundinacea, Lilijeb). Dupontia et Arctophila (sub Poa), Rupr. Fl. Samoj. (in Beitr. Pflanz. Russ. Reiches, 2), p. 62, 64, t. 6 (1845) Spp. plur.

Fluminia, Fries, Summ. Veg. Scand. 1, p. 247 (1845 s. 1846) = F. arundinacea, Fries, seu Festuca borealis, Mert. & Koch.

Scolochloa (Link), Dupontia (R. Br.), et Colpodium Arctophila (C. fulvum et C. pendulium), Griseb. in Ledeb. Fl. Ross. 4, pp. 385, 386, 393 (1853).

§ 1. Paleæ firmiores, inferior nervis 7 prominulis: gluma flores 3-4 æquantes. SCOLOCHLOA.

1. G. FESTUCACEUM. Arundo festucacea, Willd. Festuca borealis, Mert. & Koch.; Hook. Fl. Bor. Am. 2, t. 231. Scolochloa festucacea, Link, Griseb. Fluminia arundinacea, Fries.

§ 2. Rhachis spiculæ etiam barbata; glumæ scabræ, inæquales, flores 3-4 subæquantes.-GRAPHEPHORUM, Desv.

2. G. MELICOIDES, Beauv. 1. c. Aira melicoides, Michx.

Var. MAJOR. Dupontia Cooleyi, Gray, Man. Bot. N. U. S. ed. 2, p. 556. (Caryopsis libera!)

§ 3. Paleæ tenuiores; glumæ flores 2-3 subæquantes.

DUPONTIA.

3. G. FISCHERI. Dupontia Fischeri, R. Br. Poa (Dupontia) pelligera, Rupr. 1. c.

Var. PSILOSANTHUм. Poa (Dupontia) psilosantha, Rupr. 1. c. Dupontia psilosantha, Rupr. 1. c. t. 6; Griseb. 1. c.

§ 4. Gluma spicula 2-7-flora breviores; flores parvuli. ARCTO

PHILA.

4. G. FULVUM. Poa fulva, Trin. Poa (Arctophila) fulva, scleroclada, latiflora, & pæcilantha, Rupr. ex Griseb. Glyceria fulva, Fries. Colpodium (Arctophila) fulvum, Griseb.

5. G. PENDULINUM. Poa pendulina, Fl. Dan. t. 2343. Poa (Arctophila) deflexa, remotiflora, & similis, Rupr. Glyceria pendulina, Læstad. Colpodium (Arctophila) pendulinum, Griseb.

Four hundred and ninety-second meeting.

February 4, 1861.- MONTHLY MEETING.

The PRESIDENT in the chair.

In accordance with the vote passed at the last preceding monthly meeting (vide p. 112), the Academy convened at the house of the venerable Josiah Quincy, upon the occasion of his entering his ninetieth year. The Academy by its President offered an appropriate address to Mr. Quincy, who responded in some interesting remarks, and the Academy was addressed upon the occasion by the President of Harvard University, the Hon. James Savage, and Professor W. B. Rogers.

Four hundred and ninety-third meeting.

March 12, 1861. MONTHLY MEETING.

The PRESIDENT in the chair.

Professor Horsford exhibited excellent drawings, by Mr. Hand, of New York, of magnified dissections and preparations of the grain of wheat, especially of the coats and superficial portion or bran, which has been long since ascertained to contain the principal part of the gluten, this indicating the importance of retaining as much of the bran in the bread as possible.

Professor C. W. Eliot read the following paper:

On the Chromate of Chromium, and analogous Chromates, with a New View of the Constitution of the Black Oxide of Manganese. By FRANK H. STORER and CHARLES W. ELIOT.

I. CHROMATE OF CHROMIUM (Cr2O, CrO3).

1. When a solution of monochromate of potash is mixed with a solution of any ter-salt of chromic oxide, the mixture immediately becomes brownish red, a bright brown precipitate subsides, and when this precipitate has been completely deposited, the liquid separated by filtration will present the clear yellowish-red color of bichromate of potash. The chrome salt may be chrome alum, or sulphate of chromic oxide, or hydrated sesquichloride of chromium, and, if a sufficient excess of chromate of potash be added to the solution, the precipitate and the filtrate will present the appearances described. This filtrate may be evaporated and crystallized; the resulting crystals will be a mixture of bichromate of potash and of sulphate of potash or chloride of potassium, as the case may be often crystals of monochromate of potash will also present themselves. We prepared the precipitate for analysis by mixing a solution of chrome alum with an excess of monochromate of potash. The brown precipitate was washed with cold water: the color of the wash-water, at first bright yellow, became gradually paler, but never colorless. Twice in the course of the seven days during which the washing was continued, the precipitate was transferred from the filter to a mortar, stirred up with water, and thrown upon a fresh filter. This pro

cess deepened the yellow color of the wash-water in each case. It being quite evident that the color of the wash-water was due to chromic acid abstracted from the precipitate, the washing was stopped on the eighth day, the precipitate was dried at 50° to 55°, and analyzed as follows. A portion was dissolved in very dilute nitric acid by the aid of a gentle heat; the color of the solution was a red brown. Ammonia, added in very slight excess to this solution, kept at the boiling point for half an hour, produced a brownish-green precipitate of chromic oxide, which looked the browner because it floated in a bright yellow liquid. This precipitate was filtered off and thoroughly washed with hot water; it then presented the common appearance of chromic oxide, and was ignited and weighed in the usual manner. The filtrate from this precipitate and the wash-waters were concentrated by evaporation, and acidified with acetic acid. Acetate of lead then precipitated the whole of the chromic acid contained in the yellow liquid, and after the subsidence of the precipitate the supernatant liquid was perfectly colorless. The chromate of lead was washed and weighed on a tared filter as usual. The result of the analysis was

This examination showed, first, that the washed precipitate was a compound of chromic acid and chromic oxide; secondly, that it was more basic than any supposable definite compound of these two bodies; thirdly, that the prolonged washing removed chromic acid from the substance originally precipitated. To study the effect of the washing upon the precipitate, we prepared a considerable quantity of the brown precipitate by mixing a concentrated solution of pure chrome alum with a large excess of a concentrated solution of monochromate of potash. The precipitate as first collected upon the filter of course retained a considerable quantity of the bichromate of potash, chromate of potash, and sulphate of potash which existed in the filtrate. The precipitate was quickly rinsed with cold water until these mechanically adhering salts seemed to have been removed. During this short washing the substance underwent no change in color or in any other external property. A portion was now removed from the filter, air-dried on a brick, and submitted to analysis (analysis a). The rest of the precipitate was washed for six hours with cold water; another portion 25

VOL. V.