transition was not in the opposite direction? How do we know that the waterlily had not petals alone to start with, and that these did not afterwards develop, as the Wolfian hypothesis would have us believe, into stamens ?" For a very simple reason. The theory of Wolf and Goethe is quite incompatible with the doctrine of development, at least if accepted as a historical explanation (which Wolf and Goethe of course never meant it to be). Flowers can

that stamens often turn into petals. Thus the numerous coloured rays of the Mesembryanthemums are acknowledged by many botanists to be flattened stamens. In Canna, where one anther-cell is abortive, the filament of the solitary stamen becomes petaloid. In the ginger order, one outer whorl of stamens resembles the tubular

FIG. 7.-Water crowfoot (white with yellow centre)..

and do exist without petals, which are no essential part of the organism, but a mere set of attractive coloured advertisements for alluring insects; but no flower can possibly exist without stamens, which are one of the two essential reproductive organs in the plant.

Indeed, if we examine closely the waterlily petals, it is really quite impossible to conceive of the transition as taking place from petals to stamens, instead of from stamens to petals. It is quite easy to understand how the

FIG. 9.

FIG. 10.

FIG. 9.-Petal of columbine, secreting honey in its spur. FIG. 10.-Monkshood (deep blue).

corolla, so that the perianth seems to consist of nine lobes instead of six. In orchids, according to Mr. Darwin, the lip consists of one petal and two petaloid stamens of the outer whorl. In double roses (Fig. 2) and almost all other double flowers the extra petals are produced from the stamens of the interior. In short, stamens generally can be

FIG. 8.-Columbine (bluish purple). filament of an active stamen may become gradually flattened, and the anthers progressively void and functionless; but it is very difficult to understand how or why a petal should first begin to develop an abortive anther, and then a partially effective anther, and at last a perfect stamen. The one change is comprehensible and reasonable, the other change is meaningless and absurd.

In many other cases besides the waterlily, we know

FIG. 11. Petals of monkshood modified into nectaries.

readily converted into petals, especially in rich and fertile soils or under cultivation. The change is extremely common in the families of Ranunculacea, Papaveracea, Magnoliacea, Malvacea, and Rosacea, all very simple types. Looking at the question as a whole, we can see how petals might easily have taken their origin from stamens,

while it is difficult to understand how they could have taken their origin from ordinary leaves-a process of which, if it ever took place, no hint now remains to us.

In a few rare instances, petals even now show a slight tendency to revert to the condition of fertile stamens. In Monandra fistulosa the lower lip is sometimes prolonged into a filament bearing an anther: and the petals of shepherd's purse (Capselli bursa-pastoris) have been observed antheriferous.

But if the earlie-t petal; were derived from flattened stamens, it would naturally follow that they would be for the most part yellow in colour, like the stamens from which they took their origin. How, then, did some of them afterwards come to be white, orange, red, purple, lilac, or blue?

The different hues assumed by petals are all, as it were, hid up beforehand in the tissues of the plant, ready to be brought out at a moment's notice. And all flowers, as we know, easily sport a little in colour. But the question 1s, do their changes tend to follow any regular and definite order? Is there any reason to believe that the modification runs from any one colour towards any other? Apparently, there is. All flowers, it would seem, were in their earliest form yellow; then some of them became white; after that, a few of them grew to be red or purple; and, finally, a comparatively small number acquired various shades of lilac, mauve, viole, or blue.

Some hints of a progressive law in the direction of a colour-change from yellow to blue are sometimes afforded us even by the successive stages of a single flower. For example, one of our common little English forget-menots, Myosotis versicolor, is pale yellow when it first opens; but as it grows older, it becomes faintly pinkish, and ends by being blue like the others of its race. Now, this sort of colour-change is by no means uncommon; and in almost all known cases it is always in the same direction, from yellow or white, through pink, orange, or red, to purple or blue. Thus, one of the wall-flowers, Cheiranthus chamaleo, has at first a whitish flower, then a citron-yellow, and finally emerges into red or violet. The petals of Stylidium fruticosum are pale yellow to begin with, and afterwards become light rose-coloured. An evening primrose, Enothera tetraptera, has white flowers in its first stage, and red ones at a later period of development. Coba scandens goes from white to violet; Hibiscus mutabilis from white through flesh-coloured, to red. The common Virginia stock of our gardens (Malcolmia) often opens of a pale yellowish green; then becomes faintly pink; afterwards deepens into bright red; and fades away at last into mauve or blue. Fritz Müller noticed in South America a Lantana, which is yellow on its first day, orange on the second, and purple on the third. The whole family of Boraginacea begin by being pink, and end by being blue. In all these and many other cases the general direction of the changes is the same. They are usually set down as due to varying degrees of oxidation in the pigmentary matter.

If this be so, there is a good reason why bees should be specially fond of blue, and why blue flowers should be specially adapted for fertilisation by their aid. For bees and butterflies are the most highly adapted of all insects to honey-seeking and flower-feeding. They have themselves on their side undergone the largest amount of specialisation for that particular function. And if the more specialised and modified flowers, which gradually fitted their forms and the position of their honey-glands to the forms of the bees or butterflies, showed a natural tendency to pass from yellow through pink and red to purple and blue, it would follow that the insects which were being evolved side by side with them, and which were aiding at the same time in their evolution, would grow to recognise these developed colours as the visible ymbols of those flowers from which they could obtain the largest amount of honey with the least possible

trouble. Thus it would finally result that the ordinary unspecialise 1 flowers, which depended upon small insect riff-raff, would be mostly left yellow or white; those which appealed to rather higher insects would become pink or red; and those which laid themselves out for bees and butterflies would grow for the most part to be purple or blue.

Now, this is very much what we actually find to be the case in nature. The simplest and earliest flo vers are those with regular, symmetrical open cups, like the Ranunculus genus, the Potentillas, and the Alsineæ or chickweeds, which can be visited by any insects whatsoever and the e are in large part yellow or white. A little higher are flo vers, like the campions or Silenea, and the stocks (Matthiola), with more or less close! c'p, whose honey can only be reached by more special sed insects; and these are oftener pink or reddish More profoundly modified are those irregular one-sided flowers, like the violets, peas, and orchids, which have assumed special shapes to accommodate bees or other specific honey-seekers; aud these are often purple and not infre quently blue. Highly specialised in another way are the flowers like harebells (Campanula), scabious (Dipsa:ea). and heaths (Ericacea), whose petals have all coalesced into a tubular corolla; and these might almost be said to be usually purple or blue. And, finally, highest of all are the flowers, like labiates (rosemary, Salvia, &c.) and speed wells (Veronica,) whose tubular corolla has been turned to one side, thus combining the unite petals with the irregular shape; and these are almost invariably purple or blue.

The very earliest types of angiospermous flowers no remaining are those in which the carpels still exist in a separate form, instead of being united into a single conpound ovary. Among Dicotyledons, the families, some of whose members best represent this primitive stage, are the Rosacea and Ranunculacea; among Monocotyledons, the Alismaceæ. We may conveniently begin with the first group.

The roses form a most instructive family. As a whole they are not very highly developed flowers, since all of them have simple, open, symmetrical blossoms, generally with five distinct petals. But of all the rose tribe, the Potentillea, or cinquefoil group, seem to make up the most central, simple, and primitive members. They are simple low, creeping weeds, and their flowers are of the earliest symmetrical pattern, without any specialisation of form, or any peculiar adaptation to insect visitors. Now among the potentilla group, nearly all the blossoms have yellow petals, and also the filaments of the stamens yellow, as is likewise the case with the other early allied forms, such as agrimony (Agrimonia Eupatoria), and herb-bennet (Geum urbanum). Among our common yellow species are Potentilla reptans (ci quefoil), P. tormentilla, P. argentea, P. verna, P. fruticosa, and P. anserina. Almost the only white potentillas in England are the barren strawberry (P. fragariastrum), and the true strawberry (Fragaria vesca), which have, in many ways, diverged more than any other species from the norma of the race. Water-avens (Geum rivale), however, a close relative of herb bennet, has a dusky purplish tinge; and Sir John Lubbock notes that it secretes honey, and is far oftener visited by insects than its kinsman. The bramble tribe (Rube@), including the blackberry (Fig. 3), raspberry, and dewberry, have much larger flowers than the potentillas, and are very greatly frequented by winged visitors. Their petals are usually pure white, often with a pinky tinge, especially on big, well-grown blossoms One step higher, the cherries and apples (though genetically unconnected), have very large and expanded petals (Fig. 4), white toward the centre, but blushing at the edges into rosy pink or bright red. Finally, the true roses (Fig. 5), whose flowers are the most developed of all, have usually broad pink petals (like those of our own

dog-rose, Rosa canina, R. villosa, R. rubiginosa, &c.), which in some still bigger exotic species become crimson or damask of the deepest dye. They are more sought after by insects than any others of their family.

Now, if we look closely at these facts we see that they have several interesting implications. The yellow potentillas have the very simplest arrangement of the carpels in the whole family, and their fruit is of the most primitive character, cor sisting only of little dry separate nuts. They have altered very little from their primitive type. Accordingly almost all the genus is yellow; a very few members only are white; and these in their habits so far vary from the rest that they have very erect flowers, and three leafle.s instead of five or more to each leaf. One of them, the strawberry, shows still further marks of special differentiation, in that it has acquired a soft, pulpy, red fruit, produced by the swelling of the receptacle, and adapted to a safer mode of dispersal by the aid of birds. This group, however, including Geum, cannot claim to be considered the earliest ancestral form of the roses, because of its double calyx, which is not shared by other members of the family, as it would be if it had belonged to the actual common ancestor. In that respect, agrimony more nearly represents the primitive form, though its tall habit and large spikes of flowers show that it also has undergone a good deal of modification. Nevertheless, the yellow members of the potentilla group, in their low creeping habit, their want of woodiness, and their simple fruit, certainly remain very nearly at the primitive ancestral stage, and may be regarded as very early types of flowers indeed. It is only among handsome and showy exotic forms which have undergone a good deal more modification, that we get brilliant red-flowered species like the East Indian P. net alensis and P. atropurpurea. But as soon as the plants rise a little in the scale, and the flowers grow larger, we get a general tendency towards white and pink blossoms. Thus the Prunea have diverged from the central stock of the rose family in one direction, and the Pome and Rose in another; but both alike begin at once to assume white petals; and as they lay themselves out more and more distinctly for insect aid, the white passes gradually into pink and rose colour. To trace the gradations throughout, we see that the Rubea or brambles are for the most part woody shrubs instead of being mere green herbs, and they have almost all whitish blossoms instead of yellow ones; but their carpels still remain quite distinct, and they seldom rise to the third stage of pinkiness; when they do, it is generally just as they are fading, and we may lay it down as a common principle that the fading colours of less developed petals often answer to the normal colours of more developed. In the Pruna, again, the development has gone much further, for here most of the species are trees or hard shrubs, and the number of carpels is reduced to one. They have a succulent fruit-a drupe, the highest typeand though the flower contains two ovules, the ripe plum has only one seed, the other having become abortive. All these are marks of high evolution: indeed, in most respects the Prunea stand at the very head of the rose family, but the petals are seldom very expanded, and so, though they are usually deeply tinged with pink in the cherry (Prunus cerasus), and still more so in larger exotic blossoms, like the almond, the peach, and the nectarine, they seldom reach the stage of red. Our own sloe (P. communis) has smallish white flowers, as has also the Portugal laurel (P. lusitanicus). In these plants, in fact, higher development has not largely taken the direction of increased attraction for insect fertilisers; it has mainly concentrated itself upon the fruit, and the devices for its its dispersal by birds or mammals. In the Rosea, on the other hand, though the fruit is less highly modified, the methods for insuring insect fertilisation are carried much further. There are several carpels, but they are inclosed within the tube of the calyx, and the petals are very

much enlarged indeed, while in some species the styles are united in a column. As regards insect attraction, indeed, the roses are the most advanced members of the family, and it is here accordingly that we get the highest types of coloration, Most of them are at least pink, and many are deep red or crimson. Among the Pome we find an intermediate type (as regards the flowers alone) between Rose and Prune; the petals are usually bigger and pinker than those of the plums; not so big or so pink as those of the true roses. This interesting series exhibits very beautifully the importance as regards coloration of mere expansion in the petals. Taking them as a whole, we may say that the smallest petals in the rose family are generally yellow; the next in size are generally white; the third in order are generally pink; and the largest are generally rose-coloured or crimson.

Even more primitive in type than the Rosacea are the lowest members of the Ranunculacea, or buttercup family, which perhaps best of all preserve for us the original features of the early dicotyledonous flowers. The family is also more interesting than that of the roses, because it contains greater diversities of development, and accordingly covers a wider range of colour, its petals varying from yellow to every shade of crimson, purple, and blue. The simplest and least differentiated members of the group are the common meadow buttercups, forming the genus Ranunculus (Fig. 6), which, as everybody knows, have five open petals of a brilliant golden hue. Nowhere else is the exact accordance in tint between stamens and petals more noticeable than in these flowers. The colour of the filaments is exactly the same as that of the petals; and the latter are simply the former a little expanded and deprived of their anthers. We have several English meadow species, all with separate carpels, and all very primitive in organisation, such as R. acris (the central form), R. bulbosus, R. repens, R. flammula, R. sceleratus, R. auricomus, R. philonotis, &c. In the lesser celandine or pilewort, R. ficaria, there is a slight divergence from the ordinary habit of the genus, in that the petals, instead of being five in number, are eight or nine, while the sepals are only three; and this divergence is accompanied by two slight variations in colour: the outside of the petals tends to become slightly coppery, and the flowers fade white, much more distinctly than in most other species of the genus.

There are two kinds of buttercup in England, however, which show us the transition from yellow to white actually taking place under our very eyes. These are the watercrowfoot, R. aquatilis, and its close ally, the ivy-leaved crowfoot, R. heder actus, whose petals are still faintly yellow toward the centre, but fade away into primrose and white as they approach the edge (Fig. 7). We have already noticed that new colours usually appear at the outside, while the claw or base of the petal retains its original hue; and this law is strikingly illustrated in these two crowfoots. White flowers of the same type as those of water-crowfoot are very common among aquatic plants of like habit, and they seem to be especially adapted to water-side insects.

In many Ranunculaceae there is a great tendency for the sepals to become petaloid, and this peculiarity is very marked in Caltha palustris, the marsh-marigold, which has no petals, Lut bright yellow sepals, so that it looks at first sight exactly like a very large buttercup.

The clematis and anemone, which are more highly developed, have white sepals (for the petals here also are suppressed), even in our English species; and exotic kinds varying from pink to purple are cultivated in our flower-gardens.

It is among the higher ranunculaceous plants, however, that we get the fullest and richest coloration. Columbines (Aquilegia), are very specialised forms of the buttercup type (Fig. 8). Both sepals and petals are brightly coloured, while the latter organs are produced above into

long, bow-shaped spurs, each of which secretes a drop of honey (Fig. 9). The carpels are also reduced to five, the regularity of number being itself a common mark of advance in organisation. Various columbines accordingly range from red to purple, and dark blue. Our English species, A. vulgaris, is blue or dull purple, though it readily reverts to white or red in cultivated varieties. Even the columbine, however, though so highly specialised, is not bilaterally but circularly symmetrical. This last and highest mode of adaptation to insect visits is found in larkspur (Delphinium ajacis), and still more developed in the curious monkshood (Aconitum napellus), Fig. 10. Now larkspur is usually blue, though white or red blossoms sometimes occur by reversion; while monkshood is one of the deepest blue flowers we possess. Both show very high marks of special adaptation; for besides their bilateral form, Deiphinium has the number of carpels reduced to one, the calyx coloured and deeply spurred, and three of the petals abortive; while Aconitum has the carpels reduced to three and partially united into a compound ovary, the upper sepals altered into a curious coloured hood or helmet, and the petals considerbly inodified. All these very complex arrangements are. definitely correlated with the visits of insects, for the two highly abnormal petals under the helmet of the monkshood (Fig. 11) produce honey, as do also the two long petals within the spur of the larkspur. Both flowers are also specially adapted to the very highest class of insect visitors. Aconitum is chiefly fertilised by bees; and Sir John Lubbock observes that "Anthophora pilipes and Bombus hortorum are the only two North European insects which have a proboscis long enough to reach to the end of the spur of Delphinium elatum. A. pilipes, however, is a spring insect, and has already disappeared, before the Delphinium comes into flower, so that it appears to depend for its fertilisation entirely on Bombus hortorum." (To be continued.)

FR

FREDERIC KASTNER

REDERIC KASTNER, who is known to the scientific world as the inventor of the Pyrophone, has recently died, as we announced at the time, at the early age of thirty years. He was the son of an Alsacian composer of some merit, Georges Kastner, and was himself an accomplished musician. Educated partly at Paris and partly at Strasburg, he imbibed a love of science, and at the early age of fourteen years was already assisting his teachers in the chemical laboratory. When seventeen years of age he invented and patented a novel form of electromotor, in which a series of electro-magnets were caused to act in succession upon a rotating arbor. After the war of 1870-71, in which he was driven from Strasburg, he devoted himself to studying the properties of musical flames. The discovery of Higgins in 1777, that a hydrogen flame burning within the lower end of an open glass tube could set up a musical note, had been the starting point of a number of hitherto barren attempts by Schaffgotsch and others. Without knowing anything of the experiments of Schaffgotsch, Barrett, or Tyndall, young Kastner set to work to experiment, with the determination to construct a musical instrument on this principle. For two years he worked at the subject, endeavouring to temper the harsh tones of the flames and to produce a purity and constancy in their notes. He tried tubes of different sizes and forms. He varied the form of the gas jet, and essayed to introduce two or more jets into one tube. At last, in 1871, he discovered that when he employed two flames he could control their note at will, being silent when both were close together, but producing sound when they were separated. This phenomenon, which Kastner called the interference of flames, was the real starting-point of Kastner's Pyrophone or Flame-Organ, which he patented

in 1873. This organ had for its pipes glass tubes of different lengths, two hydrogen flames burning in each at the proper height. A very simple lever-arrangement served to separate the flames at will. In this form the instrument was presented to the Académie des Sciences at Paris, and publicly exhibited. Two subsequent improvements followed. A circle of small jets of common coal gas was found to answer quite as well as the two hydrogen jets, the circle being constructed so that by a simple mechanical contrivance it could be increased or diminished in size, thus separating or reuniting the flames at will. The second improvement was the application of electric currents and an electromagnetic apparatus enabling the flameorgan to be played at a distance. The first instrument of this kind constructed by Kastner was in the form of a singing-lustre hung from the chandelier in his mother's house. The pyrophone was shown at the Royal Institution in January, 1875, and at the Society of Arts in the succeeding month. It was also shown at the Loan Col lection of Scientific apparatus at South Kensington in 1876, and at the Paris Exhibition in 1878. In 1876, moreover, an account of the instrument and of the researches which led to its construction was published by Kastner under the title of "Flammes Chantantes." The strange, weird tones produced by the instrument attracted the notice of musicians. Gounod sought to introduce the pyrophone into his opera of "Jeanne d'Arc,” and Konemann at Baden Baden, in 1879, actually introduced the instrument on one occasion. A decline, however, seized the young inventor, whose strength for some years ebbed slowly away, and he died all too soon to see his invention fairly recognised by the public.

THE NEW AFRICAN EXPEDITION

IT is now understood to be quite settled that a new African exploring expedition will start next year. The Royal Geographical Society have, as might have been expected, taken the opportunity of Mr. Joseph Thomson's return from the completion of his engagement to the Sultan of Zanzibar to obtain his services as leader, and it is certain that no bettter selection could have been made.

Mr. Thomson will leave England in the Spring of 1883, and proceed to Zanzibar to organise the expedition. From Mombas, a port on the East African coast, to the north of Zanzibar, he will direct his course straight to Kilimandjaro, and do his best to explore the snowy ranges of this celebrated mountain, which but one European has as yet ever reached. Passing across the waterparting he will then descend through an entirely unknown country to the eastern shore of Lake Victoria Nyanza, and return to the coast by a more northern route, in the course of which it is hoped he may be able to visit Lake Baringo and Mount Kenia-another peak known to run far above the snow-level, but concerning which further details would be very desirable.

As a mere geographical expedition it will be thus seen that the proposed route will be one of great interest, embracing, as it does, the transit through much utterly unknown country, and the exploration of two mysterious snow-crowned mountains, which, according to the usual view of the conformation of the African Continent, appear to be quite out of place in the districts in which they are situated. But still more interesting problems will be solved, if steps are taken to investigate the unknown fauna and flora of Kilimandjaro and Kenia. The animal and vegetable life of these mountains must be entirely different from that of the plains by which they are surrounded. They will prove to have been derived either by modification from the adjacent lower districts, or by immigration from the north-in any case, presenting phenomena of first-rate importance to the student of geographical distribution.

While, however, the Society, which, with its habitual energy, has set on foot the proposed expedition, is ready and willing to do all that is necessary to ensure success in the way of geographical exploration, it does not consider itself bound to undertake the further outlay which the investigation of the natural history of Kilimandjaro and Kenia must necessarily require. To effect this in a satisfactory way, a zoologist and botanist should be attached to Mr. Thomson's staff to make the necessary observations and collections. These gentlemen might perhaps be best left on the upper ranges of Kilimandjaro,

while Mr. Thomson descends to the shores of the Victoria Nyanza, to rejoin him on his return towards the seacoast. However this may be arranged, it is obvious that the addition of two Europeans to the expedition and the transport of their collection from the interior cannot be effected without materially increasing the cost. It is hoped, therefore, that the British Association for the Advancement of Science, which has already been in correspondence with the Geographical Society upon the subject of the proposed expedition, will take up this branch of the question, and at the approaching meeting at Southampton supply the funds necessary for the purpose. It would be a great misfortune if the excellent opportunity of solving a problem of first-rate importance which thus presents itself were to be thrown away for want of the few hundred pounds required to send out naturalists in company with the proposed expedition.

NOTES

WE can only express, for the present, the deep regret with which we learn the death of Prof. F. M. Balfour, a regret which we are sure will be shared by all who know anything of Mr. Balfour's career. The details to hand of the accident which led to Mr. Balfour's death are meagre. The news reached Cambridge on Sunday evening that he had been killed by a fall on the Alps. From later information it would seem that both Mr. Balfour and his guide met with their deaths on the glacier of Fresney, on the south side of Mont Blanc, about five miles west of the village of Courmayeur. The bodies have both been found. Mr. Balfour was only thirty-one years of age.

MR. GEORGE P. MARSH, the venerable American Minister at Rome, whose death, at the age of eighty-one years, has just been announced, was known as the author of the interesting work on "The Earth as Modified by Human Action," reviewed in NATURE, vol. xi. p. 82. His well-known work on "The Origin and History of the English Language" is also marked by a true scientific spirit.

THE German Association of Naturalists and physicians meets this year at Eisenach, from September 18 to 21. In deference to the wishes of many members, the duration of the meeting has been shortened this year by curtailing the festivities which have hitherto held so large a place in the proceedings of this venerable association. The Association, however, will really begin its work on the Sunday evening (September 17) by a Zusammenkunft im Tivoli,'" and finish on the Friday (22nd) by an ex. cursion to Kissingen, the programme including lunch, dinner, supper, and ball. On the 18th, Prof. Haeckel will give a

lecture "On the Interpretation of Nature by Darwin, Goethe,

and Lamarck"; and on the 21st Prof. Rehmke lectures on "Physiology and Kantism." As the German Association meets quite a fortnight later than our own, there is nothing to hinder English men of science attending both. It is a pity some arrangement could not be come to among the various associa tions to prevent simultaneous meetings. The English, French, and American Associations all meet this year at the same time; the Americans, at least, might have arranged differently, seeing that their meeting in Montreal next month is mtended to be to some extent international.

MR. W. A. FORBES, the Prosector of the Zoological Society of London, has just left the country upon a four month's expedition up the River Niger. During his absence Mr. W. N. Parker has been appointed Deputy Prosector to the Zoological Society. To him all communications should be addressed during Mr. Forbes's absence.

THE United States Government have voted 10,000l. for the International Fisheries Exhibition. From the statement made

by the Prince of Wales at a meeting of the General Committee last week, it is evident that the arrangements are progressing

favourably.

MR. EUGENE OATES, who has been collecting in Pegu for the last fourteen years, is now in England, and has been studying for some months at the British Museum, his intention being to issue shortly a revised catalogue of the birds of Burmah, for which task his personal experiences in the field point him out as being admirably fitted.

MR. WM. DAVISON, who is so well known for his collections in Tenasserim and the Malay Peninsula, under the auspices of that energetic ornithologist, Mr. A. O. Hume, is also now in this country. We are glad to hear that Mr. Davison's health is fast becoming restored, and that he hopes soon to be able to return to the scene of his scientific explorations in Malaiasia.

VOL. I. of a large work on "Electric Illumination" will shortly be published at the office of Engineering. The volume refers to general principles, current generators, conductors, carbons, and lamps, the authors being Mr. Conrad W. Cooke, Mr. James Dredge, Prof. O'Reilly, Prof. Silvanus P. Thompson, and M. H. Vivarez; the whole will be edited by Mr. Dredge. A second volume will follow, to comprise installations, motive power, cost of production and maintenance, electrical photometry, secondary batteries, accessories to electric lighting, &c., &c., together with the completion of the patent abridgements from 1872 to 1882.

THE Algerian Government has sent to France a scientific mission to study the means of destroying the Phylloxera. It is mostly composed of viticulturists, apprehensive that the pest may eventually cross the Mediterranean.

12'

"WHENCE comes the x of mathematicians?" is a question on which M. de Lagarde supplies some curious information (in a note to the Göttingen Royal Society of Sciences). The old Italian algebraists named the unknown quantity in an equation, cosa, or res (which they either wrote out or denoted by a sign). These are translations of the Arabic šai, thing, by which the Arabians in Spain indicated the unknown quantity-writing the Arabic equivalent of š; thus our 12x would be Now it has been the rule in Spain to express the Arabic š by the Latin x. Thus our mathematical x seems to have come from the Arabic for thing. Going further back, to the Greeks, it appears that Diophantus called the unknown quantity àpieμós; and for this, a final sigma, accented, came to be written. It is thought the Arabians may have denoted this by their š, and called it by the name for thing. The Greek name for the square of the unknown quantity was dúvaus, and for the cube kúßos; and the corresponding Arabian terms are clearly derived from these by translation; hence a probability of derivation in the other case (though not by translation).

WE lately noticed a full report on education in the United States, as delineated and reviewed by the Bureau. A later Circular (No. 6) calls special attention to the present teaching of physics and chemistry. The growth of science-teaching, it says, is evident everywhere; and how the movement will culminate, no one can say. To-day, chemistry and physics are