The

AMIDOPHOSPHORIC ACID crystallises in tabular or short prismatic crystals which are insoluble in alcohol, but readily soluble in water, to which they impart a sweetish taste. solution is readily distinguished from phosphoric acid inasmuch as it yields no precipitate with silver nitrate. It evolves no ammonia upon treatment with caustic alkalies, but merely forms the salt of the alkali metal. The solution slowly decomposes into ammonium phosphate. The solutions of the acid and neutral salts of the alkaline metals yield many correspond ing acid and neutral amidophosphates of other metals by double decomposition with soluble salts of those metals.

NOTES from the Marine Biological Station, Plymouth :Last week's captures include Phoronis hippocrepia, the Actinian Corynactis viridis, and the Foraminiferan Haliphysema. In the floating fauna the Coelenterate element remains unchanged; the larvae of the Nemertine Cephalothrix have made their first appearance for the year; the number of Polychaete larvæ and of Cirrhipede Nauplii has become considerably smaller; the later stages of various Decapod Crustacea (Megalopa, Mysis-stages) have appreciably increased in numbers; and minute young

research, and the important observations made by Prof. Keeler with the great Lick refractor, and contributed to the number of Astronomy and Astrophysics for April, will be the more eagerly read. The observations were undertaken with the intention of connecting possible changes in the spectrum of the star with its period of light variability. After plotting a number of observations on the light curve of the star, the recorded appearances of the spectrum "were in some degree contradictory," although certain results were obtained, but they were left incomplete, owing to Prof. Keeler's withdrawal from the observatory. The results may be briefly stated as follows:

(1) Bright hydrogen lines C and F, bright D, line and dark D lines are always visible with the Lick refractor. Certain fainter bright lines are absent only at principal minimum.

(2) Light variations due to changes in brightness of continuous spectrum.

(3) Bright lines brightest when continuous spectrum brightest. (4) Bright lines broad and diffuse, particularly when star at maximum. D lines very hazy, so that components are hardly distinguishable.

(5) No really remarkable changes in the appearance of the spectrum took place during greater part of period. Observations show no relation between spectral changes and secondary minimum of the star.

(6) Most remarkable changes at principal minimum.

"The

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ous alga and Rhizoselenia are extremely abundant. The Hydroid Tubularia bellis, the Gastropod Nassa reticulata, and the Decapod Crustacea Pagurus lævis, Galathea squamifera, Porcellana platycheles and Pilumnus hirtellus are now breeding.

THE additions to the Zoological Society's Gardens during the past week include an Orang-Outang (Simia satyrus, 8) from Borneo, presented by Mr. Thomas Workman; a Spotted Ichneumon (Herpestes nepalensis) from India, presented by Lady Blake; a Raven (Corvus corax) British, presented by Lady Rose; a Peregrine Falcon (Falco peregrinus) British, presented by the Old Hawking Club; a Greek Tortoise (Testudo græca) European, presented by Mrs. Alcock; a Martineta Tinamou (Calodromas elegans) from Argentina, three Spotted-sided Finches (Amadina lathami) from Australia, purchased; a Panama Amazon (Chrysotis panamensis) from Panama, received in exchange; six Indian Wild Swine (Sus cristatus), four Barbary Mice (Mus barbarus) born in the Gardens.

OUR ASTRONOMICAL COLUMN. LARGE TELESCOPES.-Much has been written during the last few months with reference to the usefulness or non-usefulness of large telescopes. That the verdict is given in favour of the former is not at all surprising, for are we not far away from the limit, if there be one, beyond which larger instruments will be available? Dr. Common has many times pointed out the practicability of constructing large reflectors (his five-foot being a good example of the type of instrument he could enlarge), while the Lick instrument, the work of the Clarks, is really only a beginning of what will be done in large telescope building. For refractors it has many times been urged that the increase in size of lenses involves such a thickness that much light is thereby lost by absorption. M. Alvan G. Clark, with reference to this particular point, says a few words in Astronomy and Astrophysics for April, in which he points out that such is not the case. Greater aperture means greater light-grasping power, and as it is quite unnecessary to considerably increase the thickness of the lens, the former predominates over the latter. With the forty-inch discs, he says, only a combined thickness of four inches is required, and with lenses of an object-glass of even six feet aperture a combined thickness of only six inches would be necessary. It is pleasing to hear through him that a steady improvement is being made in manufacture of glass, and that the present discs are infinitely superior to the early ones, and "who knows," as Mr. Clark says, "how soon still more transparent glass may be at hand."

SPECTRUM OF 8 LYRE -The extreme interest that lies in this variable, especially for spectroscopists, makes it a subject of keen

bright lines disappear. The D lines become darker. Strong absorption lines appear on the more refrangible side of certain bright lines in the green, the separation of the dark and bright lines being at least five-tenth-metres. Other bright lines are perhaps similarly affected. A narrow dark line appears above the D, line at the same time. Shortly before the first maximum is reached the dark lines disappear."

Prof. Keeler adds that the method of observation he adopted was only capable of allowing him to observe a "part of a much more complex series of changes" which no doubt takes place.

SOCIÉTÉ ASTRONOMIQUE DE FRANCE.-In the Bulletin of this society for 1892, the sixth year since its foundation, several articles of importance will be found to be scattered throughout its numerous pages. Of these we may refer our readers to some selenographic studies by MM. Gaudiberi, Flammarion, and Antoniadi, examination of recent studies of Jupiter by M. Flammarion, and M. Edouard Foulséré's graphical method of determining the co-ordinates of solar spots. The valuable observations made by M. E.-L. Trouvelot on the planets Venus and Mercury, a full account of which has been given in these columns (NATURE, vol. xlvi. p. 468), will also be found here, together with a discourse by M. F. Tisserand on the movement of the moon, with reference to ancient eclipses. Among other communications M. Schmoll gives a summary, with tables, of the solar spots observed during the year 1891, M. Guillaume describes his observations on the surface and rings of Saturn, and MM. Quenisset and Trouvelot contribute their observations on planets and remarkable solar protuberances respectively. simple method of determining the positions of solar spots, and of measuring their displacements, is treated by Dr. Huette, while M. Bruguière gives a most interesting account of M. Lippmann's work on photography in colours, and M. Pluvinel on the coming (now past) eclipse of the sun.

A

WOLSINGHAM CIRCULAR, NO. 34.—With reference to the contents of the Wolsingham Circular, which we recently gave, Dr. Kreutz, in Astronomische Nachrichten, says :-"The first star, Esp.-Birni 180, is certainly given by Chandler as (2258). Auriga in his list of probable variable stars A. J. 216; see also Astronomische Nachrichten, 2764, p. 63, No. 2. The second star is evidently identical with B.D. + 57° 727 = A. G. Hels. 3032. Position for 1900: 3h. 23m. 235., + 58° 9'0. The original magnitudes of the Hels. zones are: 9'1m (February 15, 1872), and 9'om. (February 15, 1873).

ASTRONOMICAL JOURNAL PRIZES.-The judges appointed by the editor of the Astronomical Journal say a few words in the current number (No. 293) with reference to some general considerations connected with the presenting or withholding of the awards. For comet observations, allowance for optical qualities of telescopes will to a certain extent be made; relative freedom from systematic peculiarities of observation will be regarded "as a mark of excellence. Even more important than the nominal or apparent precision in other respects." For individual precision of observations, freedom from large or abnormal errors