are hemispheres, and therefore that they cannot entirely prevent contact of the plate and liquid.

That the deposition of the zinc, also, should be referred to the attraction of the plate, is that which the universal principle of attraction demands. Why not admit that that attractive force which we know exists in all things, concurs with the electrical tension to produce this, when we are constantly seeing the greatest anomalies produced by concurring forces? Thus we know that the affinity of copper for oxygen, at low temperatures, is superior to that of hydrogen; yet, when a piece of coal is saturated with hydrogen and immersed in a solution of sulphate of copper, the hydrogen is oxydized and copper reduced, simply because the attraction of the coal for the copper, added to the affinity of the hydrogen for oxygen, make a united force superior to the affinity of copper for oxygen. Here we have a voltaic circle composed of coal, sulphate of copper and hydrogen, which becomes active by the help of attraction, and is enabled to decompose an electrolyte whose affinities are even stronger than those of the produced electrolyte.

It has been considered as the standing miracle of electricity, and the unanswerable argument against the chemical theory of electrical excitation, that a battery will work in a neutral solution of sulphate of zinc, and deposit zinc on the conducting plate; for, say the advocates of the electro-motive force, the force is greater than the affinity of zinc for the negative element, for after overcoming the conduction resistance, it is still enabled to separate zinc from the negative element. But there is a little experiment which shows conclusively that it is the state of the surface of the conducting plate which determines the electrolysis, and not a supposed electrical condition involved in the nature of the substance of the plate. Let a battery of several pairs be connected with a pair of large platinum electrodes, in a solution of sulphate of zinc, containing a little free acid-or a single battery may be used if an electrode of zinc is used to receive the oxygen, then, if the platinum electrode be well polished, zinc will be rapidly deposited on it, and there will be no hydrogen given off; then let the deposited zinc be dissolved off, and the platinum electrode roughened with emery and well platinized, and then restored to its former connection with the battery; now, the same battery, with the same solutions and electrodes, will chiefly electrolyze the sulphate of hydrogen; there will be very little zinc deposited, but the hydrogen will fly off in copious

streams.

As the reservoir battery is designed chiefly for telegraphs, I may, with propriety, before closing, say a few words relative to the quantity of electricity required to work a telegraph. I have measured the quantity of the current on some lines by interposing voltametres in the circuit.

The quantity near the battery is very great compared with the quantity on the part remote from the battery, for the insulation is always imperfect; and of the whole quantity that leaves the battery, only a small proportion reaches the remoter part. But to get all the waste included in my measurement, I measured near the battery, and found when the line was in good working order, the quantity of the electricity was that represented by the solution of one grain of zinc per hour. Sometimes the line would work well with much less than a grain; and often after the batteries had been recently charged, the quantity was ten grains; but mostly, when the line was in fine order, the quantity was about the grain.

Supposing the current to be on about seven hours per day, (which I think comes near the time,) then one pound of zinc will supply all the electricity used in 1,000 days, or, say three years of business days. From this it will appear that my idea of a battery to serve 100 years is, at least, not so extravagant as to be without some show of probability. Such a battery would require zincs of only thirty-three pounds weight, or (allowing for some local action, as there is some always carried on, even by the mercury) say fifty pounds, which is a cube of less than six inches square.

I have lately had a fair opportunity of knowing the value of this battery. In May last, I charged six cells, which were put in a box in the upper laboratory, to be used in the experiments on photographic engraving. The battery has since been in almost daily use for gilding deep-sea thermometers, or other instruments, or else in the experiments. During the six months which have elapsed, it has been used probably 2000 times, in which there was nothing more required to get the current than to complete the circuit. During the intensely hot spell of the past summer, I three times added a little water to supply the loss from evaporation, and these were the only times the box was opened.

SECOND SERIES, Vol. XXI, No. 61.-Jan. 1856.

8

ART. IX.-The Vegetable Individual in its relation to Species; by Dr. ALEXANDER BRAUN.-Translated from the German by CHAS. FRANCIS STONE, B. A.

PART II. (Concluded.*)

WHILE thus, on the one hand, all the facts seem to unite in establishing the individual nature of the shoot, on comparing shoots in their qualitative relations, phenomena are brought to view which seem to contradict such a view of its individuality. The higher departments of the animal kingdom usually present as individuals representatives of the specific type agreeing in all essential respects, though, perhaps, not perfectly identical. The fact of the separation of the sexes was all that modified this view; and here, indeed, the essence of the species does seem to be divided between two different individuals. Attempts have not been wanting to obviate this contradiction by the Platonic doctrine of the original unity of the sexes, by the assertion of Paracelsus; that, in fact, the two together must be regarded as the one real individual,—and such like.

This contradiction to the usual view of what constitutes the individual is shown in a far higher degree by qualitative comparisons of vegetable shoots, not merely of the same species, but also of the same stock. Thus we see, e. g., in Equisetum arvense (Field-Horsetail) shoots totally different in aspect proceeding from the same root-stock; in early spring they are pale, discolored, unbranched, terminating with a strobilaceous-like fructification; later, green and foliaceous ones appear, verticillately ramified. Investigations into subterranean vegetation show even other varieties of shoot-formation, viz., offsets dwindling down to a point, and club-shaped buds which, at a later period, drop off of themselves. The Colt's-foot (Tussilago Farfara) presents similar phenomena, in early spring putting forth leafless shoots, with asparagus-like scales terminating with yellow capitula, which in summer are followed by others bearing leaves. The flowers in the little capitula of the first present a third variety of shoots in their lateral branchlets. Even in common life we distinguish leaf-buds from flower-buds, on many trees. Let us consider this relation in the Cherry tree, for example. On the same branch we find, on the one hand, buds which develop into branches bearing leaves, without producing flowers; on the other hand some bearing only little squamate leaves on the shortened axis,

* For Part II, see the number for September, 1855.

"For this ye must know: man without woman is not a whole; only with woman is he a whole. That is as much as to say: both together make man, and neither alone."

from whose axils the flowers rise and form a third kind of shoot.

On examining closer into the real origin of these differences, we find their ground to be a partition of the different steps of the metamorphosis (of the formations) among different shoots. True there are many plants which go through the whole series of formations, from the inferior* and the foliaceous formations up to flower and fruit; but the cases are quite numerous in which this does not take place, in which the single shoot is not able to produce all the formations. Thus there are shoots which are only able to realize the lower steps, and never attain to flowers and fruit; while others overleap all the inferior degrees and commence immediately with the formation of flowers. Hence, on the one hand, we see the metamorphosis interrupted, a stoppage taking place at a determinate step; on the other, the metamorphosis attained by passing over the intermediate steps. Still more remarkable are the cases in which the retardation is not merely an interruption at a determinate step, but appears as a real retrogression in the metamorphosis, whereby an alternate rise and fall,—an oscillation,-usually takes place, which may at last pass over in victorious progress to the formation of flower and fruit; though in most instances it prevents the shoot in question from ever attaining its end. Helleborus niger is an example of the first case; for after many years of inferior- and foliaceousleaf formation, at last it attains superior leaves and fruit by overleaping the formation of foliaceons-leaves which until then had prevented its farther progress. Many of our trees with true foliage present examples of the second case. Their branches commence with bud-scales (inferior-leaves), the succeeding foliaceous branch ends with a terminal bud, (thus falling back to inferiorleaf formation,) and in the next period of vegetation they rise again to foliaceous-leaf formation, as in the Oak, Beech, and Poplar. A similar oscillation between inferior-leaf formation and

* On the terminology of the leaf-formations, see Wydler: Bot. Zeit., 1844, 36tes. Stück, and A. Braun Verjüngung, p. 66. (Henfrey's Transl. Ray Soc., 1853, p 62, T.)

Analogous cases occur in the branches in Esculus and many Maples which attain to flowers. Among herbaceous plants Anemone nemorosa and Asarum Europawn also belong here, and especially remarkable is the Tulip, the plants of which, not yet ripe for flowering, annually develop one single foliaceons leaf, followed by a central-bud hidden in the middle of the bulb and composed of several inferior-leaves. This bud preserves this position in bulbs deep in the ground, but in those nearer the surface it is, as it were, led out of the centre of the bulb, and sinks deeper into the earth, causing an indentation of the surrounding base of the preceding leaf in form like a spur, boring through the old bulb and penetrating vertically into the ground, and at the same time sinking itself into a deeper stratum with the spur;-an arrangement explained, but not with sufficient clearness by Henry in Nov. Act. Nat. Cur, vol. xxi, p 275, t. 16 et 17.

In such librations, of course, the formation of the flower can only be attained by particular branches, deviating in character from the rest,-the catkins which pass ver leaf-formation advancing from the inferior-leaves immediately to the superiorleaves out of whose axils the flowers are emitted.

foliaceous-leaf formation, keeping pace with the change of season, is seen in the creeping main-shoot of Adora, and in the stock of Hepatica nobilis, creeping close to the soil, with its short internodes, and which in so far deserves its French name (la fille avant la mère) as its flowers, which unfold before the foliage, do not belong to the same individual as the foliage, but are produced laterally as a "daughter generation" from the axils of the inferior-leaves of the maternal stem. A similar phenomenon only in a higher degree, (a rising and falling between foliaceous and superior-leaf formation,) is presented by those plants whose inflorescence ends in a foliaceous coma, as is remarkably the case in the Pine-Apple, and also in the New Holland species of Melaleuca and Callistemon, whose crowded, brush-like inflorescence (i. e. the region covered with superior-leaves and bearing the flowers in the axils of these) returns and forms foliaceous-leaves, and in the following year again attains an inflorescence.

While every leaf-formation may bring the progress of the metamorphosis on a single shoot to a consummation, it is conceivable that one shoot may be allowed to each step for itself alone. Thus, there are shoots which represent inferior-leaf formation alone; e. g. the root-stock of Paris quadrifolia, the tuberiferous branches of the rhizoma of the Potatoe,† and there are some which are endowed with the foliaceous-leaf formation only, as the primary axis of many species of Veronica, the sterile leafy branches of several Euphorbia, as well as the leafy branches of those woody growths which have no bud-scales and no terminal inflorescence, (e. g. Rhamnus Frangula). Cases of pure superior-leaved shoots. may be seen in the peduncles of Veronica Chamadrys, officinalis, etc., in the (always lateral) spike-bearing scapes of Plantago, and the racemes of Convallaria majalis, which shoot out of the axil of the highest lower-leaf as branches. Even the leaf-formation belonging to the flower can be divided among different

*The same obtains in Galanthus nivalis, in which every annual generation consists of one inferior-leaf, one foliaceous-leaf with a vagina, and one without a vagina, which follow each other in simple alternation, in a distichous arrangement. The flower, as a branch, is emitted from the axil of the second foliaceous-leaf while the direct continuation of the shoot returns again to inferior-leaf formation. In striking contrast to the extremely simple relations of this plant we find Oxalis tetraphylla and other species of that genus, in which the subterraneous main-stem also presents an alternation of inferior leaf-formation and foliaceous-leaf formation, advancing with the change of season, but conjoined with a rare abundance of leaves and a complicated phyllotaxis. The number of the inferior-leaves amounts to several hundreds; and transverse sections of the bulbs, which last through the winter and are formed by the close approximation of these leaves, form some of the prettiest specimens of phyllotaxis, showing 21-15 arrangement through easily computable 8-, 13- and 21ranked oblique spirals. The number of the foliaceous-leaves is not so large; they develop in the summer, and form an 8 to 13 leaved rosette, out of which the axillary inflorescences issue, with their long peduncles.

In case (as sometimes occurs) the tuber does not pass through this formation and advance to foliaceous-leaf formation. The tuber is the thickened apex of the inferior-leaf shoot. Cf. the figure by Turpin: Mém. du Mus. d'Hist. Nat., t. 19, pl. 2.