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FIG. 2.-CHART SHOWING THE SYSTEM OF MILITARY PIGEON POSTS IN THE CONTINENTAL KINGDOMS.

FRANCE: 1, Mont Valérien; 2, Paris; 3, Vincennes; 4, Lille; 5, Douai; 6, Valenciennes; 7, Maubeuge; 8, Mézières; 9, Verdun; 10, Toul; 11, Langres; 12, Belfort; 13. Besançon; 14, Lyon; 15, Marseille; 16, Perpignan'; 17, Grenoble: 18, Briançon.

PORTUGAL: 1, Lisbonne; 2, Porto: 3, Valence; 4, Chaves; 5, Bragance: 6, Almeida; 7, Guarda; 8, Coimbre; 9, Castello Branco; ro, Abrantès; 11, Elvas; 12, Peniche; 13, Beja; 14, Lagos.

ESPAGNE: 1, Madrid; 2, Figueras; 3, Iaca; 4, Pamplona; 5, Oyarsun; 6, Ferrol; 7, Ciudad-Rodrigo; 8, Badajoz ; 9, Tarifa; 10, Ceuta; 11, Melilla; 12, Palma; 13, Mahon; 14, Zaragoza; 14, Valladolid; 16, Cordoba; 17, Malaga; 18, Valencia.

ITALIE: 1, Rome; 2, Ancone: 3. Boulogne; 4, Vérone; 5, Plaisance; 6, Alexandrie; 7, Mont Cenis; 8, Fenestrelle; 9, Exiles; 10, Vinadio; 11, La Maddalena; 12, Cagliari; 13, Gaeta; 14. Génova. SUISSE: 1, Thun; 2, Bâle;

Zurich: 4 3,

Weesen.

ALLEMAGNE: 1, Berlin: 2, Cologne; 3. Metz; 4, Mayence; 5, Wurtzbourg; 6, Strasbourg; 7. Schwetzingen (en projet); 8, Wilhelmshaven: 9, Tonning
10, Kiel; 11, Stettin; 12, Dantzig; 13, Koenigsberg; 14, Thorn; 15, Posen; 16, Breslau; 17, Torgau.
AUTRICHE: 1, Comorn; 2. Cracovie; 3, Franzenfeste: 4, Karlsburg; 5, Serajewo; 6, Mostar; 7, Trieste.
DANEMARK: 1, Copenhague.

SUDE: Carlsborg.

RUSSIE: 1, Brest-Litovsk; 2, Varsovie: 3, Novo-Georgievsk; 4, Ivangorod; 5, Luninetz.

firm plumage, great breadth of the primary and secondary flight feathers, and large pectoral muscles. Fig. 1 is an accurate portrait of a homing pigeon formerly in my possession that had repeatedly flown from the south of France to Brussels. Their rate of flight, for long distances, depends, of course, greatly on the weather. 1 We are enabled by the courtesy of the editor of La Nature to reproduce this map.

daylight in the morning. Fog and mist, hiding the surface of the country, are fatal to rapid progress.

It is sometimes alleged that sight can be of no avail when birds are liberated some hundreds of miles from their home, but it should be remembered that from an elevated position in the atmosphere immense distances can be seen. Mr. Glaisher records that from a balloon he saw at the same time the cliffs of Margate on the west,

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NATURE

Brighton on the south, and all along the coast-line to
Yarmouth on the north.

The homing-by-instinct theory is entirely disproved by
the races which have taken place from Rome to Belgium,
a distance of between eight and nine hundred miles,
nearly half of which was over country entirely new to the
birds. All the birds engaged in these races had been
flown from the south of France to Belgium, whence they
would have found their way back in one or two days,
but of the hundreds liberated in Rome, not one returned
before eleven days, and in the first race in a fortnight
only four out of the number despatched. The country
was new to them, and doubtless they circled about in
search of some known landmark which would have
directed their flight; but the objects with which they
were acquainted were hidden from them by the Alps,
and it was only those few that, flying along the coast,
succeeded in reaching the south of France, and then
saw objects with which they were acquainted, that
returned to their Belgian homes.

The first extensive practical application of the homing faculty of these birds took place when Paris was environed During the siege, as is well by the German army. known, balloons were continually despatched from Paris, carrying not only passengers, but bundles of letters, and the homing pigeons belonging to a few private individuals In the first instance the despatches resident in Paris. returned by these pigeons were photographed on paper and sent from Brussels into Paris. After a time a distinct pigeon post was organized from Tours, outside the German lines. This pigeon post was recognized by the English postal authorities, and letters at the cost of halfa-franc a word were sent from Tours into Paris with as great a degree of rapidity as the pigeons could be sent out by balloon, and conveyed from the places where they descended to Tours, for the purpose of being reflown into Paris. The letters, which were limited to twenty words, were set up in type, micro-photographed on thin films of collodion, inclosed in small quills, and attached to one of the tail feathers of the bird. So complete was this organization that one pigeon could have carried into Paris the whole of the many thousand letters that were sent in during the siege.

The Germans were not slow to utilize the services of the pigeons for military purposes, and at the present time every large fortress in Germany has its pigeon loft, and the birds are trained to fly back from the surrounding country for distances of many miles.

As will be seen by the accompanying map (Fig. 2), pigeons are trained to Berlin from all the large fortresses in the Empire, Strasbourg on the south to Koenigsberg on the north. Then, again, each fortress has its own loft of pigeons, which are trained to fly back to it, so that before a fortress is completely invaded by the enemy a number of birds can be sent out, or forwarded subsequently by balloon. On being liberated with despatches, these would return to the fortress, without the possibility of their being interfered with. A similar organization prevails in France, pigeons having been trained from Paris to all the military stations on the German frontier; and it may be observed that in Italy, Austria, and even Russia the same system prevails. In our own country there is no definite organization of pigeons for military purposes. It is true pigeon flying has become a popular pastime with a large number of persons. There is scarcely a town in the kingdom where some good homing birds do not exist, which could be placed at the disposition of the military or naval authorities. One great use of the birds would be on the cruisers sent out to watch an enemy's fleet. It is obvious that each could readily take a number of pigeons on board, and, without leaving its post of observation, could send back day by day messages to the town from whence the pigeons were received.

It is doubtful whether any purely military organization

could take as good care of the pigeons, and could train
them in a manner superior to that which is done by those
No military or naval
who use them for racing purposes.
them with the same amount of interest and care that is
servant, unless he were a lover of pigeons, would train
done by the amateurs.

In this country, at the present time, there exists a very large number of pigeon-flying Societies. Their races extend from the midland counties in England as far as Cherbourg, and other parts of France. In actual practice the birds would not be, except under very rare occurrences, required to fly very long distances. Of course these long flights necessitate a considerable amount of risk, but good pigeons can be calculated on to return from fifty to a hundred miles with certainty.

On looking at the map it will be seen that no lines showing the military organization of pigeons appear in Belgium; in fact, it is hardly thought necessary that any distinct organization should take place there, as it is supposed that there are in Belgium alone more than six hundred thousand homing pigeons belonging to private individuals, all of which are well trained, and would, in case of war, be placed at the disposition of Government. W. B. TEGETMEIER.

NOTES.

THE Committee which has been formed for the purpose of obtaining a portrait of Michael Foster, Secretary of the Royal Society, and Professor of Physiology in the University of Camthat the picture shall be presented either to the University or to bridge, has issued a second list of subscriptions. It is intended The treasurer decide. may Trinity College, as the subscribers is Dr. Lea, Gonville and Caius College, and subscriptions may be paid either to him or to Messrs. John Mortlock and Co., Bankers (Limited), Bene't Street, Cambridge. Cheques should be made payable to the "Michael Foster Portrait Fund."

AT the meeting of the Cambridge Philosophical Society on Monday, January 25, Prof. G. H. Darwin, President, in the chair, the following resolutions were proposed by Prof. Cayley, seconded by Dr. Lea, and passed unanimously :-"(1) That the Cambridge Philosophical Society desires to express its sense of the great loss sustained by the University and the Society by the death of Prof. Adams, who shed lustre on the Society by

the brilliancy of his scientific career, and set an example to its
the Society do now adjourn without transacting the business of
members by the earnestness and simplicity of his life. (2) That
the meeting, as a mark of respect for the memory of Prof. Adams,
(3) That the President
one of the benefactors of the Society.
be instructed to convey the foregoing resolutions to Mrs.
Adams."

WE bave heard at present of only one astronomer as candidate for the Professorship of Astronomy rendered vacant by the death of Prof. Adams; this is Mr. Turner, Chief Assistant at Greenwich. On the other hand, we hear of some mathematicians; it is not stated, however, what contributions to the science they have made.

THE late Ferdinand Roemer, the well-known geologist and Professor at the University of Breslau, whose death on December 14, 1891, we have already recorded, intended to have celebrated on May 10 next his jubilee as a Doctor of Philosophy: and his friends, admirers, aud pupils were preparing to do him It is now proposed that a marble bust honour on the occasion. of Roemer shall be placed in the Mineralogical Museum of purpose of collecting subscriptions. Breslau, and an influential committee has been formed for the

THE Committees appointed last year by the Royal Society and by the British Association for investigating the zoology of

the Sandwich Islands have amalgamated, and at a meeting held one day last month selected, from among the gentlemen who offered their services, Mr. Robert C. L. Perkins, B. A., of Jesus College, Oxford. Mr. Perkins will accordingly leave England in a few days, proceeding via New York and San Francisco to Honolulu, where he will at once commence his researches into the fauna of the islands, and especially that part of it which is believed to be threatened with extinction; aided, it is hoped, by the Hawaiian Government, and some of the principal residents. Dr. David Sharp, F.R. S., Curator in Zoology in the Museum of the University of Cambridge, is the Secretary of the Joint Committee.

THE annual general meeting of the Geological Society will be held on Friday, February 19, at 3 p.m., and the Fellows and their friends will dine together at the Hotel Métropole, Whitehall Place, at 7.30 p.m.

THE new law on French Universities is soon to be discussed by the French Senate. The Committee appointed to report upon the Government's plan disapproves of many of its provisions. M. PIERRE LAFFITTE, the head of the 66 'orthodox" Positivists, has been appointed professor, at the Collége de France, of the history of science.

DR. FRIDTHOF NANSEN is now in England, his object being to fulfil a series of lecture engagements. The proceeds are to be devoted to the expedition to the North Pole on which he hopes to start next year.

THE Joint Grand Gresham Committee has decided to cooperate with University and King's Colleges and the Medical Colleges of the great hospitals of London in the establishment of the proposed University in and for London, on the understanding that it be called the Gresham University.

DR. ALFRED CARPENTER, the well-known advocate of sanitary reform, died at Ventnor on January 27. He was the author of many works on sanitary subjects. In 1879 he was elected President of the Council of the British Medical Association, having been in the previous year orator of the Medical Society of London.

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venient mode of communicating information to persons at home, to the numerous correspondents officially connected with colonial and Indian botanical establishments, and to private persons interested in plant products in distant parts of the Empire. It has also been of service to members of the general public engaged in planting or agricultural business in India and the colonies.

THE fourth part of the first volume (xxi. of the whole work) of the fourth series of Hooker's "Icones Plantarum" has appeared, completing this volume, which is devoted to the illustration, by Sir Joseph Hooker, of Indian orchids of a less conspicuous character than those commonly cultivated. The work is now published for the Bentham Trustees, and sold at four shillings per part by Dulau and Co., of London. The third series, consisting of ten volumes, containing 1000 figures of interesting plants, is on sale by the same firm, at £5 the set. Only a limited issue is printed, and when exhausted it will not be reproduced.

MR. ELLSWORTH has offered to lend for exhibition at the "World's Fair," Chicago, a collection of orchids, including between 1500 and 2000 varieties.

THE Chemical Institute of the Royal University, Rome, has printed a volume of reports on the researches carried on by its workers during the scholastic year 1890-91. Excellent service might be done to science if this example were followed by the laboratories connected with our own Universities.

THE Director of the Colonial Museum at Haarlem has issued a circular notice to the effect that it is of the highest importance for the Museum to have in its library all recent treatises on tropical botany, zoology, products, and cultivation. He begs therefore that authors will send to the Museum a printed copy of their writings on these subjects in the publications of scientific Societies.

THE Times of Tuesday, February 2, contains an account of a very peculiar case of prolonged sleep which, on January 31, was occupying the attention of medical circles in Germany. It seems that a miner named Johann Latus, an inmate of the hospital at Myslowitz, in Silesia, has been there 4 months, and during that time all attempts that have been made to wake him have been fruitless. The doctor attending him, Dr. Albers, thinks that catalepsy is the real cause of his condition, although no previous record of so prolonged a sleep has ever been made in medical science. The fact which has led Dr. Albers to this conclusion is that all the limbs are absolutely rigid. In other respects the appearance of the man betrays no sign of this. The body remains quite still, breathing takes place regularly, and the appearance of the face is quite normal, the cheeks being of a healthy colour. Lately the body has been less rigid and the patient has even made some slight movement, but the eyes have still been kept closed, and the condition of apparent sleep in no way disturbed. During this long sleep the hair on the head has increased in length, but the beard has remained stationary. In order to supply the patient with food a tube has been inserted into the throat, and by means of it two or three litres of milk have been administered

AN index to the five yearly volumes of the Kew Bulletin, already published, has now been issued as Appendix IV., 1891." In an introductory note some interesting statements are made as to the history of the Bulletin. It was originally intended that a number should be issued only occasionally; but monthly publication was immediately found to be necessary, and further space has since been obtained by the printing of information of a purely formal kind in appendices. The daily. subjects treated have related almost entirely to economic botany. The results of investigations made by members of the staff at Kew and of kindred institutions at home and abroad on vegetable products and the plants producing them, have been carefully summarized and presented in as concise and clear a manner as possible. In many cases the articles have been illustrated by plates from original drawings or by those placed at the disposal of the Director by the Bentham Trustees from the "Icones Plantarum." The Bulletin has become a most con

M. KOEBELE, who has been for the second time searching in Australia and New Zealand for "beneficial insects," has discovered that Orcus chalybeus, a steel-blue ladybird, is a most important enemy of the red scale. According to Insect Life, he has found them by the hundred, and has observed the mature insects eating the scales. The trees were "full of eggs," and the larvæ were swarming on all the orange and lemon trees infested with the red scale. M. Koebele has sent to America a large quantity of the eggs and many of the adult beetles.

ACCORDING to the Berlin correspondent of the Times, a curious rosy light overspread the sky above Berlin from 9 till 11 o'clock on the evening of January 26, and made many people think that a great fire had broken out somewhere. Early on the following morning the Emperor telephoned to the central fire brigade station to inquire what had happened, but received answer that the effulgence was a natural phenomenon.

IN March 1891, a Select Committee of the House of Commons was appointed to consider the subject of the registration of teachers. Two Bills which had been introduced into the House of Commons, one by Sir Richard Temple, the other by Mr. Arthur Acland, were referred to the Committee; and it examined a large number of witnesses whose opinions were worthy of being carefully considered. The Report of this Committee has been issued by the National Association for the Promotion of Technical and Secondary Education, and deserves the attention of all who are interested in educational questions. The following are the conclusions at which the Committee arrived: that the registration of teachers in secondary schools is in principle desirable ; that any Educational Council to be established for the furtherance of such registration should be composed of nominees of the State, representatives of the Universities, and members elected by the teaching profession; that the qualifications for registration should include evidence both of attainments and of teaching

capacity; and that additional facilities are required for the

training of teachers in secondary schools. The Committee was of opinion (a) that existing teachers should not be put on the register merely as such, but should not suffer from any legal disability; (b) that both existing teachers and future teachers should be admitted to the register on producing such evidence of intellectual acquirements and teaching capacity as might be required by the Council; (c) that the register should, as soon as might appear reasonable in such case, be made compulsory upon existing teachers in the event of their appointment to teach in a secondary school, assisted by endowments or public money, and upon future teachers in these, and ultimately in all other secondary schools; (d) that teachers certified by the Education Department should be placed on the register, with an indication, as in the case of other teachers, of the nature of their certificate.

THE Committee on the Indexing of Chemical Literature, appointed by the Chemical Section of the American Association for the Advancement of Science, refers with pleasure, in its ninth annual report, to the fact that a new Dictionary of Solubilities is in progress by a competent hand. Prof. Arthur M. Comey, of Tufts College, College Hill, Massachusetts, has written to the Committee that the work he has undertaken will be as nearly complete as possible. He estimates that the dictionary will contain over 70,000 entries, and will make a volume of 1500 to 1700 pages. The arrangement will be strictly alphabetical, and in all cases references will be given to original papers. The Committee also prints a letter fin which Mr. Howard L. Frince says that in the U.S. Patent Office, of which he is librarian, an index is being made for about 150 journals, notably those upon the subjects of chemistry, electricity, and engineering, both in English and foreign languages. The general plan is alphabetical, but he departs from it sufficiently to group under such subjects as chemistry, electricity, engineering, railroads, &c., all the subdivisions of the art, so that the elec trical investigator, for instance, will not have to travel from one end of the alphabet to the other to find the divisions of generators, conductors, dynamos, telephones, telegraphs, &c. other fact mentioned by the Committee is that an extensive bibliography of mineral waters is being prepared by Dr. Alfred Tuckerman.

An

THE Institute of Jamaica has begun the issue of special publications. The first, the Rainfall Atlas of Jamaica, contains thirteen coloured maps showing the average rainfall in each month and during the year, with explanatory text. The maps are based upon observations made at 153 stations from about the year 1870 to the end of the year 1889. The available stations are irregularly distributed, being for the most part sugar-estates and cattle-pens, and in consequence of this irregularity the island has been divided into four rainfall divisions. The northeastern division has the largest rainfall, then comes the west central, next the northern, and lastly the southern. The annual distribution of the rainfall varies from 30 to 35 inches in a few places to over 100 inches in the north-eastern division. The greatest fall is in October, and the least in February. The driest stations are on the north-eastern and south-eastern shores. The maps show the distribution and average amount of rainfall very clearly by different tints, and cannot fail to be of both scientific and practical utility. The work has been prepared by Maxwell Hall, the Government Meteorologist.

IN the new number of the London and Middlesex Notebook, Mr. G. F. Lawrence says that some months ago he obtained a stone hammer of unusual form from the Thames at Hammersmith. It is in the form of a cushion, and is beautifully polished all over. The shaft-hole is 1 inch in diameter, and is an inch nearer one end than the other. The material is a

beautifully veined claystone, of a light greenish colour, and the hammer measures 4 inches in length, 2 inches broad, and is I inch thick. Mr. Lawrence knows of only two other specimens of this type which have been found in the southern counties; both are in the British Museum. The Edinburgh Museum, however, contains several, some of handsome material and finish, while others are of a less beautiful, but most serviceable granitic stone. The type seems to belong to the Bronze Age. Such specimens as the Hammersmith example must have been, Mr. Lawrence thinks, more than mere implements. He suggests that they were symbols of chieftainship, and handed down from one to another, as sacred badges of office, as the beautiful jade weapons were in New Zealand.

MR. E. P. RAMSAY, Curator of the Australian Museum, Sydney, has reported to the trustees that during the year 1890 no fewer than 320 specimens were bought for the ethnological collections. The most important of them were a fine lot of greenstone axes and old clay cooking-pots from New Caledonia; fine-made mats, baskets, hats, native hair lines and fishing hooks, from Gilbert and Kingsmill Group; necklaces, drums, and other rare articles of native dress, from British New Guinea; clubs, spears, cava-bowls, and food-baskets, from Viti or Fiji; stone headed spears, from Bathurst Island, Torres Straits. Among 74 specimens acquired by exchange were a valuable collection of Neolithic worked flints from the Chalk Hills, South Downs, England; worked flints, from the Thames; Paleolithic worked flints, from the river gravels, near London; polished basalt celts, from Ireland; celt socket, formed of the base of the red-deer, from Swiss lake-dwellings; old English flint and steel, from Yorkshire; modern French peasant's pipe-lighter, flint and steel; iron lamp, or "cruzie," in use since Roman times in Scotland; brass lamp, being a modification of the "cruzie," from Antwerp; cornelian arrow-tips, from Arabia; photographs of Hindu pipes.

AN excellent hand-book on "Viticulture for Victoria" has been issued by the Royal Commission on Vegetable Products in that colony. The work has been compiled by Mr. François de Castella, of whom the Commission says that from training and experience he is especially qualified for the task of preparing a manual for vine-growers. During the last few years a fresh impetus has been given to this industry in Victoria, and Mr.

Castella is of opinion that the amount of wine produced in the colony will soon be very considerable. He recommends that the vine-growers of each district should agree among themselves to produce only one definite type of wine, and that it should be known by the name of the district-such as Rutherglen, Great Western, Bendigo, Mooroopna, and so forth. The label on a bottle would thus give some idea of the contents. wine from the sort of grape is useless. Two Rieslings-for instance, one grown on the Yarra and the other on the Murray -differ as much as hock and sherry.

To name

MR. CLEMENT REID read an interesting paper the other evening before the Norfolk and Norwich Naturalists' Society on the natural history of isolated ponds. He selected as typical examples the isolated ponds dug on the South Downs to store water for cattle. These ponds are from 300 to 400 feet above sea-level, supplied by rain and condensation, and quite unconnected with any stream, often far from a road or path ; and it appears most unlikely that seeds of the plants, or eggs of the animals, which he found in considerable numbers and variety, can have been conveyed thither by human agency. Both the eggs and the seeds must, he thinks, have been transported chiefly on the feet of birds.

MESSRS. LONGMANS have in the press and will shortly publish a new and revised edition of Sir Philip Magnus's "Lessons in Elementary Mechanics." The book, which has already passed through seventeen editions, has been entirely rewritten by the author. It contains several new sections, and especial attention has been given to the subject of units and to the explanations of terms. No change, however, has been made in the general arrangements of the book. A key containing full solutions of all the exercises and examination questions, many of which are new, is ready for press, and will be published about the same time as the new edition.

A BOOK by Prof. A. Targioni Tozzetti on the insects and other animals which injure tobacco has recently been published. Of his 300 pages of text, 270 are devoted to insects, 6 to vertebrates, 7 to snails, 10 to arachnids, and I to earthworms. Dealing with the cigarette beetle (Lasioderma serricorne), which, of all tobacco insects, does most damage in America, Prof. Tozzetti recommends as a remedy a thorough use of chloroform, bisulphide of carbon, and hydrocyanic acid gas in disinfecting warehouses and manufactories; and he advises, where possible, the submersion of the tobacco in 90 parts of water for fortyeight hours. Insect Life says of this advice that it is " evidently

not based on experience, and not appreciative of the ease with which tobacco is spoiled for the trade."

In the last sentence of Mr. Frederick J. Smith's letter on "A Simple Heat Engine" (NATURE, p. 294), for "fall" read "pull."

A SERIES of remarkable compounds of the halogen salts of the rare metal cæsium with two more atoms of chlorine, bromine, or iodine, are described by Messrs. Wells and Penfield in the January number of the American Journal of Science. The fact was accidentally discovered that when bromine is added to a concentrated solution of cæsium chloride, CsCl, a dense brightyellow precipitate is produced. When the contents of the testtube are warmed, this precipitate dissolves, but on cooling the same substance separates out in the form of large orangecoloured crystals. Upon analysis these crystals are found to possess the composition CSCIBr. This remarkable observation has led to the preparation of a series of eight such salts, each containing one atom of cæsium and three halogen atoms. The formulæ of these compounds are CsI ̧, CsBrI, CsBr2I, CsClBrI, CSCII, CsBr, CSCIBr, and CsCl2Br. They all crystallize well, generally in large brilliant prisms. Those of CsI, are

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black and almost opaque; those of CsBrI, dark reddish-brown by reflected and deep red by transmitted light; CsBr,I forms crystals of a bright cherry-red colour; while the crystals of CSCIBrI, CsBr2, and CSCIBr, are tinted with various shades of orange. The compound CsCl,Br forms bright yellow crystals, the lightest coloured in the whole series. Two other possible salts of the series, CsCII, and CsCl, have not yet been obtained. The general method by which the above eight salts were prepared consisted in dissolving the haloid salt of cæsium employed in water, adding the requisite quantity of iodine or bromine, or leading a stream of chlorine through the solution, and cooling or evaporating to the crystallizing point. The salts are remarkably stable, they may all be preserved for any length of time in corked tubes or bottles. They form an isomorphous group, all crystallizing in the rhombic system. An important relation has been discovered between the crystallographical constants of the first five members of the series, those containing iodine. The ratio of two of the axes remains almost constant throughout the whole of the five, while the third varies with the molecular weight.

THE formation of salts of the nature above described, in which a compound such as cæsium chloride, which is usually considered as fully saturated, actually combines directly with two more atoms of a monad halogen element, is a most important and interesting fact considered in connection with the general subject of residual affinity. Cæsium, as is well known, is the most electro-positive element yet discovered, and that it should exhibit this phenomenon of residual affinity in so startling a manner is perhaps not surprising. Moreover, Johnson in the year 1877 obtained a tri-iodide of potassium, KI3, and also in 1878 an analogous ammonium compound, NH,I,. The question of the constitution of such salts is a most complex one, but the balance of evidence, particularly that afforded by the crystallographical measurements, is decidedly in favour of considering them as double salts, and not as salts of trivalent cæsium. The acceptance of a possible trivalency of cæsium would of course be in direct antagonism to the teaching of the periodic generalization, and Prof. Mendeleeff himself considers the two extra atoms of iodine in potassium tri-iodide to be united much in the same manner as the water taken up by many salts upon crystallization.

THE additions to the Zoological Society's Gardens during the past week include a Grey Ichneumon (Herpestes griseus 8) from India, presented by Mr. R. Meinertzhagen; a Lesser Whitenosed Monkey (Cercopithecus petaurista) from West Africa, deposited; two Snow Buntings (Plectrophanes nivalis), a Yellow Bunting (Emberiza citrinella), two Reed Buntings (Emberiza schaniclus), British, purchased; seven Coypus (Myopotamus coypus), born in the Gardens.

OUR ASTRONOMICAL COLUMN.

NEW STAR IN THE MILKY WAY.-The following circular was issued from the Royal Observatory, Edinburgh, 1892, February 2:

Yesterday an anonymous post-card was received here bearing the following communication:

"Nova in Auriga. In Milky Way, about two degrees south of x Auriga, preceding 26 Auriga. Fifth magnitude, slightly brighter than x."

At 6h. 8m. G. M. T. the star was easily found with an operaglass. It was of a yellow tint, and of the sixth magnitude, being equal to 26 Auriga. Examined with a prism between the eye and the eye-piece of the 24-inch reflector, it was immediately seen to possess a spectrum very like that of the Nova of 1866. The C-line was intensely bright, a yellow line about D fairly visible; four bright lines or bands were conspicuous in the green; and, lastly, a bright line in the violet (probably Hy) was easily seen.

A telegraphic notice was sent to Greenwich in the afternoon,

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