prominently brought before our notice, it may perhaps seem premature to pursue its action further back in the history of the universe. However, it seems but natural that we should apply this hypothesis to explain the close connection that holds between certain of the so-called elements. Pre-supposing that this theory has not been discussed before, I will just mention the chief grounds for holding it, and leave the examination into its truth or falsity in the hands of more experienced chemists. Herbert Spencer defines evolution as the integration of matter at the expense of force; this integration being accompanied by a loss of polarity, and by specialisation in a certain direction. Thus much being granted let us see how far this change from simple to complex is traceable in the qualities of certain of the elements, as seen especially in those that fall under natural groups.

In the first place, we may call some of the metals more generalised than others. Thus all hydrogen salts are soluble in water; so, to a less extent, are those of lithium, sodium, and potassium; but as the atomic weight (or mass) increases, so the salts of those metals become less and less soluble. This is only true speaking generally, for we see that, in particular cases, the hydrate of barium is more soluble in water than that of calcium, &c. But, as a rule, the salts of barium are less soluble than those of strontium; these, again, than calcium salts. But, on the whole, we may say that with increase of atomic mass of the metals, their salts lose their general properties and become more and more specialised, the salts taking their character from the metal in combination.

Secondly, according to this hypothesis, increase of atomic mass should be accompanied by absorption of motion. Just as the very complex molecules, of which living organisms are built up, are deficient in polarising or crystallising force, so are also the more massive chemical atoms: for it is evident that the heavy atoms of lead and bismuth have far less of this force, called chemical affinity, than have the light sodium, or the still lighter hydrogen atoms. In colloid bodies, the atomic attractions are mostly used up in keeping together the comparatively great masses of the molecule hence but little polarity, or attraction among the molecules themselves, is manifested, and the compounds from the union of these molecules are unstable. So, too, the more massive atoms of elements enter with more difficulty into combination, and the products formed are unstable. Thus, the chlorides of platinum, or the oxides of lead, &c., are less stable, and more difficult of formation, than the corresponding salts of potassium or magnesium. Whereas colloids and crystalloids readily unite together: this is paralleled by the strong affinity that hydrogen, or any metal, has for chlorine or oxygen. Here the metal is the light crystalloid, the non-metal, the colloid, so to speak. It is only with the more specialised of the metals, those which we have seen have massive atoms, that hydrogen will unite, viz., antimony and arsenic; and the compound it forms with the former is very unstable, whilst the hydride of bismuth is unknown. These compounds are not alloys like that of hydrogen with palladium, but they show the comparatively non-metallic nature of arsenic and antimony. This consideration leads us to suppose that the non-metals are still more highly evolved than the metals, and that in the special direction towards electro-negative polarity. Besides we know that the intermediate links differ in degree, not in kind.

The lessening of the atomic heat with increase of mass shows a further absorption of motion, besides the potential energy possessed by the more massive atoms. It might be objected that motion has never been extracted from these massive atoms; on the contrary, as a rule, the heat of combustion is greater as atoms of the element entering into combustion are lighter. But the molecules of organic matter must be decomposed by suitable means before they can do any work; just so with the elements, which receive their name for the very reason that, as far as we know, they are incapable of decomposition. Perhaps, indeed, the increase in the number of rays in the spectra of highly heated sulphur and nitrogen will be regarded as an instance of such motion.

Thirdly, if we look at the atomic weight of groups of the elements, it is seen that the increase of mass occurs by a simple proportion. Gladstone, Dumas, Odling and others have shown the close relation of the numbers for particular groups; whilst lately Mendelejeff has given out a law of periodical recurrence, connecting the properties and the atomic weight, either received or theoretical, of all known elementary bodies. Thus we

have

These instances suffice to show how near the calculated ato nic weights come to those found by experiment.

In the fourth place it is a significant fact, that the elements themselves become changed in properties under different circumstances; the allotropic forms that result may be said to correspond with "varieties " among organised bodies. In the case of the elements greater atomic mass was said to denote evolution; in the best known allotropic varieties we find change from the normal form to be accompanied by increased density. Thus ozone (allotropic oxygen) and red phosphorus have both a greater density than the usual forms of these bodies.

With greater evolution, the so-called elements become more electro-negative; so in these instances, ozone has a greater affinity for hydrogen and the metals than has oxygen, and amorphous phosphorus less affinity for oxygen than ordinary phosphorus.

The varieties of sulphur would seem to be exceptions, for they are of less density than the usual form; the specific gravity of crystallised sulphur is 2'05, that of plastic sulphur, 195. However Berthellot terms the crystallised octagonal variety, electronegative, plastic sulphur, on the contrary, electro-positive. Hence the octagonal form is at once denser and more electro-negative, and should be regarded accordingly as more highly evolved.

In the fifth place, let us note some of the actions and reactions of matter and forces.

(a) Heat: In any organic group, generally speaking, the greater the vapour density, accompanying greater complexity, the higher is the boiling point. So it is with the elements, taken according to natural groups, the greater the atomic weight, the higher the fusing or boiling point. This is seen in the case of chlorine, bromine, and iodine; arsenic, antimony, and bismuth, &c. Exceptions to this rule are the three closely allied metals, zinc, cadmium, and mercury, the most volatile of which is the heaviest, the least volatile, the lightest. Again, the more complex the chemical constitution of bodies is, the worse, generally, do they conduct heat and electricity: so too the more highly evolved and massive the atoms, the worse conductors are they as a rule. This applies strictly only to groups, as calcium conducts better than barium or strontium, but silver, though heavier and of greater atomic weight, nearly five times better than calcium. The difference of conducting power between metals Where the atomic mass is and non-metals is very apparent. greater, as the body verges more towards the electro-negative, this loss of conductibility and the high fusing point is easily accounted for by the mechanics of motion. The heavier atom takes longer to communicate its motion in the one case; or is more difficult to move in the other.

Some natural groups of the elements offer good examples of what has just been stated, e.g.

(3) In the case of Light, not much can be said as yet: but with regard to radiation and absorption of radiant heat, Tyndall has shown that the complex molecules of organic vapours are the best radiators, and that uncombined atoms can hardly be said to radiate or absorb at all. So we see that the simple, "metallic" vapours radiate but ill, whilst the more complex atoms do not reflect, but rather absorb light and heat rays. Indeed, we may suppose, that as in the case of complex vapours, the more highly evolved atoms, requiring a greater supply of force, turn these rays that fall on them to account; whilst the metals dispense with them by reflecting them.

(c) The chief relations of electricity have already been alluded to. The chemical affinity between elements increases as they differ in electric polarity; and the more highly evolved, the more chlorous or electro-negative are they.

Lastly, late researches have shown that the elements nitrogen and sulphur at a high temperature, give more complex spectra. This fact, if it be a fact, has thrown some doubt on their claim to be regarded as absolute elements.

In explaining the phenomenon, we should probably consider the sulphur particle to be composed of several groupings of the ultimate element, which, driven apart by the action of heat, are made to vibrate separately with various velocities. Thus the allotropic form of oxygen, ozone, has been represented by a simple formula, being made up, as it is supposed, of two groupings of the element oxygen, that being the ultimate atom.

The above statements seem to me to agree in showing, that if the hypothesis of evolution is tenable at all, it can be extended to explain all or nearly all the relations between the elements at present existing on this globe. C. T. BLANSHARD Queen's College, Oxford

Ancient Balances

Apropos of Mr. Chisholm's interesting account of ancient weighing instruments, in your last number, I venture to call his attention to the representation of an equal-armed balance in an Egyptian papyrus of the nineteenth dynasty, about 1350 B.C. It is to be found in the celebrated "Ritual of the Dead," a hieroglyphical papyrus of Hunnefer, of the reign of Seti I. In the "Judgment Scene" the heart of the deceased is represented as being weighed in a balance in the Hall of Perfect Justice, and in the presence of Osiris. The balance is of the ordinary equal beam construction, the final adjustment being attained by a sliding weight on one side of the beam, exactly like the "rider on our exact balances. The papyrus may be seen in the British Museum. G. F. RODWELL

Brilliant Meteors

ON Saturday evening (Oct. 18), about half-past 8 o'clock, I observed, from Boltsburn, Durham, a meteor of considerable brilliancy in the north-western part of the sky; it shot downward from an elevation of about 40°, and left a streak of very red light on its path. The streak continued visible for nine or ten seconds. JOHN CURRY

Boltsburn, Oct. 20

LAST evening, October 26, when returning home I observed a brilliant meteor stream across the sky. It may be worth while to record it.

Not having my watch, I can only guess the time as about 8.20 P.M. The first appearance was like a flash of lightning intensely white, arresting attention at once. When observed it streamed from & Persei above Capella (in altitude) and disappeared in Lynx. For two-thirds of its course its light was very bright, and it left a brilliant train of sparks, but for the remaining third it merely showed its own single expiring light.

Later in the evening when observing with the telescope in Cepheus, two shooting stars crossed the field at different times, apparently from the same radiant. T. T. S. Thruxton Rectory, Hereford

SIR HENRY HOLLAND

ALTHOUGH the late Sir Henry Holland, whose name has been familiar to the world during the greater part of the present century, cannot be regarded as a man

eminent in scientific research, still, as a Fellow of the Royal Society of nearly sixty years' standing, as President of the Royal Institution, as one who was ever ready to contribute towards the advancement of scientific research, and as the friend of all the most eminent men of science of his time, which was a long one, we deem him worthy of more than a passing notice.

As much as for anything else, Sir Henry was known as an indefatigable traveller; his fondness for travelling, indeed, having led to the illness which was the immediate cause of his death on October 27 last, his 86th birthday. He had very early in his career deliberately determined to set aside two months each year for the purpose of indulging his favourite recreation. This year, immediately after his return from a visit to Russia, he set off for Naples in September last, staying a short time at Rome and Paris on his way home. He arrived in London on October 25, suffering from a slight cold, which was sufficient, notwithstanding the wonderful robustness of his constitution, to cut him off in two days. He began his travelling career by a visit to Iceland in 1810, since which he has explored almost every corner of Europe, and been eight times in America. In his "Recollections of Past Life," published in 1872, he speaks thus of his travels:

"The Danube I have followed with scarcely an interruption, from its assumed sources at Donau-Eschingen to the Black Sea-the Rhine, now become so familiar to common travel, from the infant stream in the Alps to the 'bifidos tractus et juncta paludibus ora' which Claudius with singular local accuracy describes as the end of Stilicho's river journey. The St. Lawrence I have pursued uninterruptedly for nearly 2,000 miles of its lake and river course. The waters of the Upper Mississippi I have recently navigated for some hundred miles below the Falls of St. Anthony. The Ohio, Susquehanna, Potomac, and Connecticut rivers I have followed far towards their sources; and the Ottawa, grand in its scenery of waterfalls, lakes, forests, and mountain gorges, for 300 miles above Montreal. There has been pleasure to me also in touching upon some single point of a river, and watching the flow of waters which come from unknown springs or find their issue in some remote ocean or sea. I have felt this on the Nile at its time of highest inundation, in crossing the Volga when scarcely wider than the Thames at Oxford, and still more when near the sources of the streams that feed the Euphrates, south of Trebizond."

It was mainly on account of the reputation which even then he had achieved as a traveller, that he was elected a Fellow of the Royal Society in 1815.

Sir Henry was elected President of the Royal Institution in 1865, and took the very warmest interest in its success, and in the promotion of scientific research, being seldom or never absent from his post, doing much to popularise science among the upper classes, among whom, as our readers know, he was always a welcome guest. For fifteen years Sir Henry contributed 40%. annually to a fund specially set apart for the promotion of research, and was always ready to take by the hand promising young students who were diffident of their own abilities. Sir Henry himself never knew what it was to struggle, no man ever slid more easily into the highest professional and social position, and no man was ever probably less He counted from the very first spoiled by his success. among his patients, many of whom became his intimate friends, the highest in social and political rank both at home and abroad, and the most eminent in literature, science, and art, knew nearly everyone whose name during the last sixty years has been before the public, and was respected and loved by all with whom he came in contact. Sir Henry had naturally good abilities, great tact and knowledge of the world, a mind stored with knowledge gained from books, from travel, and from his intercourse with men, which, combined with his genial

bearing, rendered his society wonderfully delightful. As a physician, he was possessed of high skill.

66

Of Sir Henry's contributions to literature, his "Medical Notes and Reflections" (1839) and his "Chapters on Mental Physiology" (1852) are well known to the medical profession. He contributed a considerable number of articles to the Edinburgh, and other reviews, which, in 1862, were published as Scientific Essays." In 1815, he published his celebrated "Travels in the Ionian Isles and Greece," of which a second edition appeared in 1819; a work abounding in classical, antiquarian, and statistical information, interspersed with interesting details respecting manners and customs, scenery and natural history. In 1816 he contributed to the "Philosophical Transactions" a memoir on the manufacture of sulphate of magnesia at Monte della Guardia, near Genoa, and afterwards papers to various other scientific journals. Last year he published his well-known "Recollections of Past Life," a volume which must long keep Sir Henry Holland's name alive. His memory will be cherished by all who knew him as something ever pleasant to recall.

The Royal Institution has thus, within a year, lost its Secretary and its President, not to mention the resignation of its Professor of Chemistry, who has not yet been replaced. Whoever is elected to fill the Presidential office will, we doubt not, keep up the traditions of the place, and do what in him lies to carry out the original design of the founders and donors of the Institution, never losing sight of the fact that above everything it is meant to be one of the few temples of original scientific research in the country. Its laboratories have recently been rebuilt, and we hope they will ever continue to be taken ample advantage of for purposes of study and research, not only by the earnest successors of the great men who have rendered them famous, but also by competent members, for whom they were originally equally intended by the enlightened and science-loving men to whom the conception of the Institution was originally due.

We conclude this notice by giving a few of the dates, in addition to those already given, which mark Sir Henry Holland's career. He was born at Knutsford, Cheshire, Oct. 27, 1787, and was educated at Newcastle-on-Tyne, and at the school of Dr. Estlin, near Bristol, where he became head boy. In 1804 and 1805 he attended Glasgow University, and in 1806 he entered the Medical School at Edinburgh, where he became acquainted with many of the notable men that then frequented "the grey metropolis of the north"-Sir Walter Scott, Brougham, Sydney Smith, Horner, Jeffery, Dugald Stewart, Sir William Hamilton. In 1816, after spending some time in travel, he established himself in London, and at once achieved high professional success. He became Physician in Ordinary to the late Prince Consort in 1840, and to the Queen in 1852; and next year was created baronet. Sir Henry was twice married, his second wife, who died in 1866, having been the daughter of his old friend Sydney Smith.

THE AMERICAN MUSEUM OF NATURAL HISTORY IN CENTRAL PARK, NEW YORK *

FOR

OR many years a large number of the generous and public-spirited citizens of New York had long felt the need of a museum and library of natural history that should be on a scale commensurate with the wealth and importance of their metropolitan city, and would encourage and develop the study of natural history, advance the general knowledge of kindred subjects, and to this end furnish popular amusement and instruction. In 1868 a remarkable opportunity presented itself of securing a rare collection that would form an admirable nucleus for such a

* A Paper read by Albert L. Bickmore, Ph. D., Superintendent, at the Meeting of the American Association.

comprehensive museum. The most extensive dealer in specimens in the world, Edouard Verreaux, of Paris, suddenly died, leaving in the hands of his widow a collection, which, at the rates he was accustomed to sell specimens, would have brought over 500,000 francs, 100,000 dols. in gold. . . . Dying suddenly, he left the rich gatherings of an industrious lifetime seriously embarrassed with debt. This opportunity it was decided to try to improve, and a subscription of nearly 50,000 dols. was at once made up as a beginning, and since that time about 100,000 dols. have been contributed in money, though the present property of the institution, including the large donations of specimens which have been steadily coming in, could not be replaced, nor could other as interesting and valuable specimens for less than 250,000. A rare and nearly complete collection of American birds, and many fine birds of paradise and pheasants were first purchased by Mr. D. G. Elliott. While negotiations were about to be opened for the Verreaux collection, a second museum unexpectedly became available. Prince Maximilian of Neuwied on the Rhine above Bonn (not the Emperor Maximilian of Austria and Mexico) died, and the young son inheriting the estate had no scientific taste, and offered the results of his father's life-work for sale. The elder Prince, who formed the collection, passed 1815, 1816, and 1817 exploring Brazil from Rio up to Bahia, and of course a large proportion of the great collections he secured had never at that early date been seen by scientific men in Europe before, and were therefore types of new species.

This collection the American Museum purchased entire. An agreement was soon after made with Mme. Verreaux by which all the choice specimens in her cabinet not contained in the Elliott and Maximilian purchases were selected for the muscum, and all these specimens have been safely received from Europe, and are now on public exhibition in Central Park. Large donations of shells, corals, and minerals have been received, and one collection of 20,000 insects. The liberal subscriptions first made induced the principal subscribers to consent to act as trustees for the fund and property acquired by it, and by a special Act of the Legislature they were created a body corporate--they and their successors to have entire and unrestricted control for ever over all the muscum property. They have limited their number to twenty-five, and the survivors fill every vacancy, thus securing a fixed policy and stable character to the institution. An arrangement has been made between the trustees and the Department of Public Parks in New York by which the city may furnish lands and buildings, while the collections are to be bought and cared for by moneys contributed by the trustees themselves and the generous public. In pursuance of this plan, by which the authorities of the city and private citizens might cooperate toward the common end of establishing a large museum, 500,000 dols. were appropriated by the city to commence a suitable thoroughly fire-proof edifice, and the Department of Parks was authorised to set apart so much of the public lands under their control as they might deem proper and necessary for the proposed structure and its future extensions.

The great object of the museum is twofold. First, to interest and instruct the masses which already throng its halls, and occasionally number over 10,000 in a single day; and, secondly, and especially to render all the assistance possible to specialists. These wants are shown to be amply met by the large, palatial saloons for the public, and over the whole building a high Mansard story, containing spacious and well-lighted rooms with every modern convenience, where naturalists from every part of the country may pursue their favourite studies for any length of time, and be secure from all possible interruptions. The building will undoubtedly be ready for occupation in the spring of 1875.

raria, but it is unknown in America. It is easily to be discriminated from the common species (see Fig. 4 on p. 510) by the absence of that dark, sub-triangular patch which extends backwards from the eye in R. temporaria. The male of R. esculenta is further to be distinguished from the male of the common Frog by the fact of its having the floor of the mouth on each side, distensible as a pouch-the pouches, when distended, standing out on each side of the head. These pouches are called "vocal sacs," and no doubt aid in intensifying these animals' croak, which is so powerful that (on account of it and

FIG. 7-Poison Organ of Thalassophryne reticulata (after Günther). 1, Hinder half of the head with the venom-sac of the opercular apparatus in situ. Place where the small opening in the sac has been observed. a, Lateral line and its branches; b, gill-opening; c, central fin; d, base of pectoral fin; e, base of dorsal fin. 2. Operculum, with the perforated spine.

world, except Australia, and parts more southerly still, and except countries situate above 66' north latitude. In South America, however, but a single species is as yet known to exist.

Amongst the largest species are Rana tigrina, of India and the Indian Archipelago, and the bull-frog (R. Mugiens)

FIG. 10. The female of Nototrema marsubiatum, with the pouch partly cut open (after Gunther).

because of the country where they are common) they have been nicknamed "Cambridgeshire Nightingales." Specimens from Cambridgeshire are preserved in the British Museum.

A large South American Frog (Ceratophrys cornuta), which devours other smaller Frogs as well as small birds and beasts, is noteworthy on account of the singular bony

FIG. 8.

FIG. 9. FIG. 8--Vertical, Longitudinal Section of the Poison-fang of a Serpent (after Owen). g, deep grove; o, its lower termination, which affords exit to the poison;, pulp-cavity. FIG. 9.-Magnified Transverse Section of a Serpent's Poison-fang (after Owen). g, groove round which the substance of the tooth (containing, the pulp-cavity) is bent; /, the point where the sides of the tooth meet and convert the "groove" into what is practically a central cavity.

of North America. The latter animal may often be seen in the Gardens of the Zoological Society, where it is fed on small birds-a sparrow being easily engulphed within its capacious jaws.

The Edible Frog, par excellence (R. esculenta), is found in England as well as on the Continent of Europe. It is as widely distributed over the old world as is R. tempo

*Continued from vol. viii p. 512.

FIG. 11.-The Surinam Toad (Pipa americana).

plates which are enclosed in the skin of its back: a character which it shares with a small South American Toad (Brachycephalus ephippium), and which we shall hereafter see to be a point of special interest.

A Frog newly discovered (of a new genus but one allied to Rana), called Clinotarsus,+ has been

*The type of this genus is a species which was in my own collection (with no clue to the locality whence it originally came), but is now deposited in the British Museum. It was first described in the Proceedings of the Zoological Society for 1868, under the name Pachyhatrachus.

t Proc. Zool. Soc., 1869.

(see Fig. 5, vol. viii. p. 511) represented, in the hope that by the wider circulation of a figure of it, it may be recognised, and its habitat so ascertained.

It

The common Toad (Bufo vulgaris) is as widely distributed over the earth's surface as is Rana esculenta. is less aquatic than the frog, and more sluggish in its motions. In shape it resembles the frog, but is more swollen, with much shorter legs and a warty skin (see Fig. 6, vol. viii. p. 511). The toes are less webbed, and the margin of the upper jaw, as well as the lower, is entirely destitute of teeth. The jaws are similarly toothless in all toads.

The toad is provided with an oblong, elongated gland called Parotoid) behind each eye. These glands emit a milky secretion which is acrid and very unpleasant to the

superficial resemblances to frogs, are termed "Batrachoid." He found in the fish no less than four spines each per

mouth of some carnivorous animals. Those who have observed a dog attacking a toad can hardly have failed to notice the disgust which the former animal seems to exhibit by the copious flow of its saliva, its many headshakings, &c. The toad's secretion, however, cannot be said to be poisonous, and certainly it is not so in the mode in which the venom of serpents is poisonous, since a chicken may be inoculated with it, and yet appear to suffer no injury whatever beyond the infliction of the slight wound necessary for the performance of the opera

tion. Nevertheless the secretion exercises a very decided effect upon certain animals, since the tadpoles both of frogs and of salamanders are very powerfully affected by being kept in the same water with a toad, if the latter be specially irritated in order to make it discharge its pungent and irritating secretion.

True poison and organs fitted both to inflict wounds and to convey the venom into them are not indeed found in any animals which are even near allies of the frogs and toads. Nevertheless a very perfect organ for both wounding and poisoning has been discovered by Dr. Günther to exist in a certain fish (Thalassophryne reticulata), belonging to a group which, on account of their

FIG 15.-The Flying-trog (from Wallace's "Malay Archipelago ")

side of the hinder part of the head in front of the gill opening. Two others were dorsal spines placed one behind the other on the mid-line of the back. These