precipitate. From the foregoing results, it would seem little doubt remains that microlite is a tantalate rather than a columbate of lime.

5. Redondite.

I have examined still farther the hydrous phosphate of alumina and iron described by me in a previous number of this Journal (vol. xlvii, p. 338), as occurring so abundantly in the island of Redonda, W. I., and am now of the opinion that it constitutes a species distinct from barrandite, from which it differs in several particulars, and essentially in specific gravity. Barrandite has gr.=2.576. Redondite gives gr.=2019, which may be presumed to be a little too high, as the three examples used in the determination were found on analysis to give 8.8 p. c. of silica.

The phosphoric acid was determined on the same specimens by the molybdate of ammonia process; and amounted to 40.192 p. c. But as the silica (8.8 p. c.) was obviously accidental, the proportion of phosphoric acid in the pure mineral will stand at 44.07 p. c. The water is 24.73 p. c.

6. Phosphoric acid in the Diaspore of Chester, Mass.

Heermann having found phosphoric acid in the diaspores of several localities, I thought it worth while to analyze a good crystal of this mineral from Chester. It was semi-transparent and of a rich hair-brown color with a faint tinge of violet. Sp. gr. 3.343. The phosphoric acid was determined by the molybdate of ammonia. I obtained

Water,

Phosphoric acid,.

15.80

0.32

Protoxyds iron, with traces of manganese.... 0.38
Alumina not determined; but by difference...83.50

7. The Pelham Vermiculite?

100.00

It occurred to me as possibly interesting to make some chemical examination of this rather curious exfoliating mica, described by Mr. Adams in a late number of this journal (vol. xlix, p. 271). It is very abundant, and to the eye apparently as homogeneous as other softened micas.

It loses on an average 7 p. c. of water by ignition. By digestion in hot aqua regia, half its weight comes; into solution, leaving behind 50 p. c. of minute, colorless scales, closely resembling margaric acid. They are so remarkable for their uniformity of size, freedom from color, and pearly luster, as scarcely to suggest their inorganic composition. Under the microscope, however, they very nearly give the distinct lateral

cleavage lines of mica; nor have they the perfect elasticity of a true mica. They show no tendency to farther exfoliation when heated; before the blow-pipe they melt with difficulty on the edges into a colorless glass. Prof. DesCloizeaux was kind enough to examine some of these scales optically; and found them to be uniaxial, from whence it is probable that they belong to the species biotite.

The solution in aqua regia afforded the following result in reference to 100 parts of the dissolved material.

No search was made for alkalies; but from the result obtained it is apparent that the magnesia in part explains the use made by the farmers of this material for a fertilizer, as described by Mr. Adams.

The point, however, which most interested me was the discovery thus accidentally made of the cause of the worm-like exfoliation in the mineral, viz: from the coating of the mica scales with a hydrated, argillaceous mixture, which probably owes its origin to the decomposition of some other species of the micaceous or chloritic family. In subjecting a fragment of the vermiculite of Millbury, Mass., to a similar action of aqua regia, the result was an abundance of brilliant green scales, probably belonging to the species ripidolite. It may therefore be suggested, that many earthy species of minerals (silicates) will under analogous treatment be found to be less homogeneous than has been supposed.

Amherst, May 7, 1870.

ART. XIII-Notice of a new Species of Gavial from the Eocene of New Jersey; by Professor O. C. MARSH, of Yale College.

THE Museum of Yale College has recently received some interesting reptilian remains from the Eocene greensand of New Jersey, which indicate a new species of Gavial, considerably smaller than any Crocodilian heretofore discovered. These specimens, which were found together, and are evidently parts of the same skeleton, consist of various fragments of the skull, and ten vertebræ. The coössification of the neural arches of the vertebræ, and the almost entire obliteration in some of them of the sutures, would imply that the individual, although diminutive, was nearly or quite mature.

AM. JOUR. SCI.-SECOND SERIES, VOL. L, No. 148.—JULY, 1870.

The few portions of the skull preserved are sufficiently characteristic to show that the animal had an elongated muzzle, and that the upper and posterior parts of the head were of the gavial type. The form of the parietal bone indicates, moreover, that the temporal apertures were large, and near together, with their adjoining sides nearly vertical. The quadrates are elongate, unusually straight on the inner side, and their condylar surfaces deeply and obliquely notched. The pneumatic foramen, on the upper surface of the quadrate near the inner edge, is very large, and characteristic. The teeth of this specimen were unfortunately not secured.

The vertebræ are well preserved, and present marked characters. The articular cup is transversely oval in the cervicals and anterior dorsals, and has its upper margin depressed in the posterior dorsals. The hypapophyses are simple and elongate. The neural canal of the cervical and anterior dorsal series is transverse, and sub-rectangular in outline, and the floor unusually broad and flat. In the posterior dorsals the canal, although still transverse, becomes less rectangular, with the broader por

tion above.

The principal dimensions of the tenth, or first dorsal, vertebra are as follows:—

The species here described may perhaps prove to be generically identical with the one named by the writer Thecachampsa Squankensis, which is the only Crocodilian hitherto found in the Eocene of New Jersey. The genus Thecachampsa, however, as proposed by Prof. Cope, cannot yet be regarded as a valid one, since the concentric structure of the dentine, on which it was founded,* is not a character of generic importance; for it occurs in various other Crocodilians, and also in some of the Cetacea. The present remains, therefore, may be placed provisionally in the genus Gavialis, and the species be called Gavialis minor. It may readily be distinguished from Thecachampsa Squankensis, aside from its greatly inferior size, by the posterior dorsal 'vertebræ, which have the cup and neural canal transverse, instead of vertical, and especially by having the bodies of these vertebræ proportionally more elongate, and without the remarkable constriction, which is one of the most striking characters of the latter species.

* Proceedings Philadelphia Acad. Nat. Sciences, 1867, p. 143.

The present specimens indicate that the animal to which they belonged was quite slender, and about six feet in length. They were found by Hugh Hurley, Esq., in the Eocene greensand of Shark River, Monmouth county, New Jersey, and by him presented to the Museum of Yale College.

New Haven, Conn., June 10th, 1870.

ART. XIV.—On Hydrogenium-amalgam; by O. LOEW, of the College of the City of New York.*

WHEN zinc-amalgam is shaken with water, a slow decomposition of the latter takes place, recognized by the formation of flocculi of hydrated oxyd of zinc, and the evolution of small bubbles of hydrogen on allowing the mixture to stand for a time. This decomposition of water by zinc is intensified when a small quantity of bichlorid of platinum is present; a spongy body then being formed on the surface of the zinc-amalgam. This body I have found to be an alloy of hydrogenium and

mercury.

In order to obtain the hydrogenium-amalgam on a larger scale, zinc-amalgam containing a few per cents of zinct is shaken thoroughly with about an equal volume of a solution of bichlorid of platinum containing about 10 per cent of the chlorid, care being taken to keep the mixture cool. The zinc-amalgam swells up considerably, precisely as in the ammonium-amalgam experiment, and continues to evolve hydrogen till the decomposition of the amalgam is complete. I have found that the volume of the hydrogen thus developed was, in several experiments from 100 to 150 times that of the mercury employed. This hydrogen possesses a faint but peculiar odor.

When this amalgam of hydrogenium (prepared with about 5 per cent of zinc) is pressed directly after its preparation, between sheets of filtering paper and then spread out in a layer (not too thin) to the air, the temperature soon rises considerably, and vapors of water are formed, which may be condensed in a glass receiver. The finely divided platinum present is obviously the cause of this rapid oxydation of the hydrogenium. In this action of platinic chlorid upon zinc-amalgam oxychlorid of zinc is at the same time formed; and though this may be removed by means of hydrochloric acid, yet by this treatment a part of the hydrogenium-amalgam is destroyed. If, after this, it be

* Read before the Lyceum of Natural History, Chemical Section, Apr. 11. A zinc-amalgam containing more than 5 per cent of zinc is a solid, and in this state, is not well fitted for use. though it would doubtless produce more hydrogenium in the amalgam. A zinc-amalgam of 5 per cent is readily liquified at a moderate heat and should then be immediately used.

washed with water, it undergoes a very slow decomposition, the volume increases and bubbles of hydrogen escape through the water above. An addition of zinc-amalgam or sodiumamalgam greatly accelerates the decomposition of the hydrogenium-amalgam.

Platinum after perfect amalgamation does not aet as energetically as in its nascent state; i. e., when precipitated on the amalgam. When platinum-amalgam is mixed with zinc-amalgam the decomposition of the water by zinc is extremely slow and the hydrogenium-amalgam does not appear for some time. Under certain conditions moreover, the hydrogeniumamalgam is formed without the aid of platinic chlorid. I had at one time about twenty pounds of mercury containing zinc, which was left standing in a bottle with water for three weeks; the hydrogenium-amalgam formed on the surface of the mercury, gradually decomposing above and being renewed from below.

Graham compares hydrogenium to the active modification of oxygen, and no doubt there is much analogy between them. We may distinguish three modifications of hydrogen; namely, (1) common nascent hydrogen formed by the action of sodiumamalgam on water, or by that of zine and hydrochloric acid; it has a strong reducing power but cannot form hydrogeniumamalgam; (2) common gaseous hydrogen which has at common temperatures only a very weak reducing power; and (3) hydrogenium. There are reasons for believing that these differences may be expressed by the following formula:

ART. XV.-The Brachiopoda, a Division of Annelida;* by EDWARD S. MORSE.

AT a meeting of the Boston Society of Natural History, June 1st, 1870, Mr. Edward S. Morse made a verbal communication on the position of the Brachiopoda in the animal kingdom. He referred to the branch of Mollusca as it was understood forty years ago, when misled by external characters, many worms, like Serpula and Spirorbis, and a group of Crustaceans, the Cirripedia, were included with mollusks, and that from a proper recognition of their characters these diverse forms had

* Abstract from Proceedings Boston Society Natural History.