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SAVE THE DEAD LEAVES.-If every horticulturist would reflect for a moment on the nature of fallen leaves which contain not only the vegetable matter, but the earthy salts, lime, potash, &c., needed for the next season's growth-and that, too, exactly in the proportion required by the very tree and plant from which they fall-nay, more, if they would consider that it is precisely in this way, by the decomposition of these very fallen leaves, that nature enriches the soil, year after year, in her great forests, it would scarcely be possible for such a reflecting horticulturist to allow these leaves to be swept away by every wind that blows, and finally lost altogether. A wise horticulturist will diligently collect, from week to week, the leaves that fall under each tree, and by digging them under the soil about the roots, where they will decay and enrich that soil, provide in the cheapest manner the best possible food for that tree. In certain vineyards in France, the vines are kept in the highest condition by simply burying at their roots every leaf and branch that is pruned off such vines, or that falls from them at the end of the
THE ANEMONE. According to Linnæus, the anemone is a native of the south-east of Europe. Voorhelm, however, informs us in a treatise on the hyacinth, that a French gentleman, M. Bachelier, introduced it into France from America in the last century; and by assiduous attention to its cultivation, greatly improved the species. It at length fell into the hands of the Flemish and Dutch florists, who made still further advances towards the perfection to which the present numerous-named varieties have arrived. The flower, from its gay and striking colours, soon became popular; and vast numbers were imported into this country, which has continued up to the present time, for they have maintained the superiority in the culture of this flower, although our English gardeners have by no means been backward in their exertions to improve upon the productions of our foreign neighbours; for, among the lists of the select sorts will be found many bearing English names, which take their
standing at the present time among the most superb sorts; and although this be the case, the anemone-taking into consideration the varied colours they possess, for there are numerous shades of blue, from light tint to dark, also of scarlets and reds down to pale rose colour; purples to the same extent, claret and violet, &c., all of self colours; then follow white grounds, variously tipped, shaded, or spotted, with the above colours in such a manner as to have the most pleasing effect-yet it is seldom you meet with them in the flower-gardens. How to account for this we are at a loss, for they are not difficult of cultivation. Ordinary sandy soil flowers them very well, so that it has been tolerably well manured; and if not, manure can be added; old cowmanure is best, but they do not dislike horse manure. The double varieties do not produce seed in any quantity; the semi-double and single seed freely, and if a little care be bestowed in selecting a few of the best for colour and form as seeders, you may expect to have some superior flowers among them. One thing is certain - that is, the variations of shades will be almost as numerous as the seed sown, and also, the forms of the flowers will be equally diversified. For our own part, we admire alike the single and double, the principal feature being the varied display of brilliant shades, which are more particularly to be admired coming as they do in the spring, when so few flowers are to be seen. But this is not all they may, by good management, be flowered in the autumn. On the 10th of November, 1852, we had the pleasure of seeing some sixty or seventy blooms of anemones, fully and beautifully grown. These flowers were the product of seeds on the 21st of July, 1851; they were principally single, but among them were several semi-doubles, most superbly striped and blotched. It is needless to say, that they were the admiration of all present. The anemone is far more hardy than the ranunculus, and will bear more drought; moisture is, however, indispens able to them, and must be supplied arti ficially when nature does not afford it. The brilliant colour of this beautiful flower must always render it a favourite of the lover of plants.-Farmer's Journal.
OUTLINES OF POPULAR SCIENCE
FOR CHILDREN OF ALL AGES. (A SKETCH OF PROFESSOR FARADAY'S LECTURES TO CHILDREN-THIRD ARTICLE.)
SINCERELY hoping that our young readers have experienced no difficulty in following our previous descriptions, or in performing the experiments mentioned, we resume our pleasing task of making known some further properties of oxygen, "the virtue of atmospheric air." Our present report, we beg to say, before proceeding further, will chiefly consist of details for conducting certain experiments -some very brilliant experiments; others, although not brilliant, yet extremely interesting.
The Editor trusts that all his young philosophers will remember how oxygen gas was made; how it was driven-forced out of the salt chlorate of potash by means of heat; how we managed to avoid the necessity of a furnace, by putting some lighted charcoal on a fire-shovel; and finally, how the leading property of oxygen (at that time introduced by name), was illustrated by means of an ignited chip of wood. Perhaps it will be remembered also that the distillation of oxygen gas from chlorate of potash, even with the aid of a strong charcoal fire, was no very easy operation. The oxygen came over with some little difficulty, and the glass of the retort became soft with the excess of heat. Before proceeding with any further experiments on oxygen, Professor Faraday required a further stock of the gas; and this he did not generate by the same process as before,-namely, by heating in a retort, chlorate of potash alone, but a mixture of chlorate of potash and black oxide of manganese. By adopting this expedient, the oxygen comes over with great facility, not even requiring a charcoal fire, but merely the flame of a spiritlamp. A very curious point, too, is this:the black oxide of manganese, although promoting the evolution of oxygen from the chlorate, yet undergoes no change itself.
gen gas, and instead of using the firepan, the far more convenient spirit-lamp may now be employed. Neither will it be required to use a retort. A large test tube, fitted up with a perforated cork, and a small bent tube, as represented in the accompanying wood-cut, being quite sufficient. But stay.We have not yet described how the hole is to be bored through the cork in question. This may appear a very simple operation to many, Fig. 22. but its performance requires peculiar treatment, which a novice would not readily discover for himself. There are sold by philosophical instrument makers, little tubes of brass, termed cork-borers. They are in appearance very much like the brass ferules of a fishing-rod, and sharpened at one end to an edge by means of a file. By means of an instrument of this description, a hole, clear, round, well defined, may be made through a cork with the greatest facility; and when made, it may be slightly enlarged, if necessary, by means of what is called a rat's-tail file. Whenever a piece of glass tube is required to be thrust through a cork in the manner just described, the fitting must be quite accurate, else the junction will be useless. The slightest chink or crevice is sufficient to permit the escape of gas. This absolute accuracy can only be secured by carefully attending to certain little details, which we shall now proceed to explain. Let not the young chemist think them trivial, or pass them over; whether he is to succeed in his experiments or fail, will mainly depend on his attention to, or negligence of details, such as these. Having bored a hole in the cork, then it is required to push the end of a glass rod tightly through it; and the young chemist, in trying to accomplish this, is frequently apt to forget that glass is glass. He is apt to employ an injurious amount of force, just the amount he would have employed had the glass tube been a rod of iron or of wood. Thus the tube becomes shattered, and not unfrequently the operator's hands are cut. The chief impediment to the ready passage of the extremity of
Before performing the experiments presently to be described, it will be necessary to generate a further portion of oxy
a glass tube through a cork is this. The end of the tube, when cut or broken off from another piece, has usually sharp edges, like a knife, which edges pressing against the soft matter of the cork, drive the latter in fragments before them, and thus spoiling the accuracy previously existing of the perforation. To obviate this defect, the knife edges must be destroyed. This can be very easily accomplished by means of the spirit-lamp flame, in which, if the end of the tube be held for a time, the knife edges fuse, and the orifice of the tube becomes slightly contracted, thus favouring its passage through the cork. If it be pressed whilst still hot through the latter, all the better.
It now remains to adjust the outside of the cork exactly to the diameter of the distilling tube. This is not accomplished by cutting, but by careful filing, the cork being fashioned into a tapering shape in such a manner that the very extremity is somewhat less than the orifice of the tube. Finally, all the preceding directions having been attended to, the tube itself will require to be bent, which can be readily accomplished by holding it in the spirit lamp flame. Does any reader think that all these long directions are tedious, trivial, unimportant? The case is simply this, if they be not absolutely attended to the operations to be described will fail. Therefore let the reader take his choice, either to set about his experiments according to our directions, taking heed of every admonition, however minute, or to forego these experiments altogether. Supposing, then, the distilling apparatus to be quite ready; about two teaspoonfuls of chlorate of potash, intimately mixed with an equal portion of black oxide of manganese, are to be put into the large tube, and the various parts of the apparatus being joined, heat is to be applied, and the oxygen gas which comes over is to be collected. The proper vessels to be employed in performing the experiments, presently to be described, with oxygen are gas jars, as illusFig. 23. trated by the annexed wood cut; but provided such cannot be obtained, tolerably efficient substitutes may be made by cutting off the lower parts of
wide-mouthed pint bottles; an expedient, by the way, which will prove far more expensive than the purchase of some proper gas jars at once.
Resuming the thread of his discourse, Professor Faraday said: "Let us now see the effects of this oxygen gas when brought to bear on certain bodies which are known to be combustible even in atmospheric air. First of all let us see its effects on charcoal; for this purpose I take a piece of charcoal, through which a hole has been perforated; I pass through the hole a wire, having previously tied the end of the wire into a sort of knot; then at its other extremity the wire is passed through a round metallic disc, and finally through a cork, in such a manner that when all are put together, as indicated, an apparatus may be formed of the kind represented." We illustrate the combination by a diagram. "The charcoal thus suspended
on a wire, I ignite by holding it in the flame of a spirit lamp; the slightest point of ignition is sufficient, and when thus ignited I plunge it into a jar containing oxygen gas. Remark, now, how beautifully, how brilliantly the charcoal burns, throwing off its Fig. 24. coruscations in every direction, like so many little meteors shooting through the jar; remark, too, the kind of combustion which ensues-it is rapid, violent, but totally devoid of flame. This distinction between combustion with, and combustion without flame, is highly important, and I shall have a good deal to say concerning the subject hereafter. I will only state at this time, that flame can only result from the burning of a volatile substance, such as a vapour or a gas; an illuminating flame can only, then, occur under certain circumstances.
"Now charcoal is not volatile; on the contrary, it is one of the most fixed bodies with which we are acquainted. If heated in a closed vessel out of contact with atmospheric air or oxygen, it suffers no diminution of weight; hence during combustion it does not yield a flame. Yet by a beautiful and wonderful provision of the Almighty, this property of carbon is so far modified in certain instances, hereafter to be described, that it yields a flame of the most vivid kind. However, our pre
sent theme is oxygen, not charcoal; therefore I will pass on to show you the effects 3 of this element upon ignited sulphur. Having placed some sulphur in a little copper tube attached to a copper wire, 5 and the latter to a metallic disc and cork, S as before, I ignite the sulphur by holding it in the flame of a spirit-lamp, and plunge it into a glass-jar containing oxygen. Rapid combustion, you observe, ensues, a peculiar blue light being diffused all around. In this operation of combustion, there is a flame, a very beautiful flame, but not highly illuminative. The conditions necessary to illumination are still not here. Let us now perform a third experiment. Instead of charcoal or sulphur, let us take iron; a substance which has already been demonstrated capable of burning, even in the atmospheric air. Let us see what will be the result of causing it to burn in oxygen gas. The details necessary for the successful performance of this experiment are as follows::—a length (some eighteen inches) of steel piano-wire, being tightly wound round a small rod or glass tube, a coil is formed. This coil now being unfolded, and slightly extended, a helix or corkscrew-like form results. One end of this helix is to be unwound and straightened; then it is to be fitted with metallic disc and cork, as already described; the other end being supplied with a very small chip of wood. The point of a match is very good for this purpose, but it must not be attached to the wire by simply thrusting the latter through it. The very extreme point of the wire being filed thin, like the point of a needle, is to be tightly wound round the chip of wood, by means of a small pair of pliers. All matters being thus arranged, the chip of wood may be ignited by holding it in the flame of a candle or spirit-lamp, and when ignited it may be plunged into a jar containing oxygen gas. The chip will immediately take fire, and, burning, will set fire to the fine extremity of iron wire, which begins to throw off coruscations in all directions, and the fire gradually extending, proceeds, from the very end of the wire considerably further back into its corkscrew-like portion. Here again," remarked Professor Faraday, we have no flame; sparks are evolved just as we noticed them to have been during the
combustion of charcoal. The result, however, is very different in this case, as we shall make out hereafter; for whilst all the charcoal by combustion seems to have been dissipated, on account of its conversion into a gaseous or invisible form, the iron wire by combustion has been changed into little fused globules, not of iron, but of an oxide of iron, or combination of iron with oxygen; some of these globules have been heated to such a degree of intensity, that, falling against the sides of the glass jar, they have almost perforated the latter, and falling on the plate, have even buried deeply into it, notwithstanding they must have previously sunk through a layer of cold water.
"On the facts supplied by the burning of a piece of iron wire in oxygen gas, hangs a celebrated and a most important chemical doctrine. This doctrine I shall have occasion to advert to hereafter; meantime, what I have stated respecting a great and all important chemical doctrine being founded on a correct observation and interpretation of appearances rendered evident by this result, will teach you the propriety of thinking attentively on the bearings of every appearance manifested in the course of an experiment.
"A philosopher desirous of extending the boundaries of our knowledge, should set out in his career with the determination to consider nothing as trivial-to regard no phenomenon, however seemingly uniniportant, as beneath his notice. It is absolutely impossible to value correctly the importance of any new truth. To correct thinkers, it may seem trivial, or it may seem important just in proportion as an immediate application for it may be evident; but the philosopher regards no truth as trivial or unimportant. Years— centuries may, perhaps, roll on without an application for it being found. No matter. Though not for us, or our immediate successors, a discovered truth is nevertheless a new impulse directed towards the moral elevation of mankind. One more experiment with oxygen in illustration of its powerfully combustive force, and we will pass on to the consideration of other elements; yet oxygen will come before us indirectly again and again; we cannot avoid this mighty element, if we would! In one condition or another it
pervades the whole economy of the world. Gas vapour, liquid or solid, oxygen may exist in all. In the thin, mobile, fleeting atmosphere, the mighty oxygen is there :in water, that very type of inactivity—it is there. In aquafortis and oil of vitriol, Istill this wonderful element exists. flint, and in clay, in saltpetre, gunpowder, in the very earth we tread upon, in the substance of trees and plants, in blood and hair, skin and muscle, nerve and bone,-oxygen pervades all and every one. We cannot bid farewell to this mighty element if we would, but we can bid farewell to it in its pure simple, uncombined gaseous form; for that state exists not in nature, it is produced by the disposing agency of man. One experiment more, then, for the purpose of illustrating the combustion-supporting powers of oxygen in this state.
"The combustion of phosphorus in oxygen is exceedingly brilliant and not dangerous, if the following instructions be implicitly attended to. The copper ladle in which the combustion is effected must be of considerable depth, and the phosphorus employed should not be more than sufficient to half fill, when fused, the copper dish. Moreover, the phosphorus employed must be perfectly dry, the drying to be accomFig. 25. plished by means of contact (not friction) with blotting-paper. Finally, the phosphorus, when placed in the ladle, is to be ignited by touching it on the surface with a piece of hot wire, not by holding the ladle which contains it in the flame of a candle or spirit-lamp. All these directions having been attended to, the phosphorus, as soon as ignited, may be plunged rapidly but steadily into the glass jar designed to contain it, and standing, as usual, in the middle of a soup-plate with water. The combustion resulting is exceedingly brilliant, because, in the instance under consideration, the two conditions necessary to accomplish this result are supplied. The phosphorus itself is a volatile body, and the result
of its combustion is a solid. These circumstances, however, will be rendered more evident by and bye. Thus have we accomplished the combustion of four dif ferent bodies with oxygen; namely, charcoal, sulphur, iron, and phosphorus. We have seen the most intense effects produced. We have seen each substance dis appear, and light and heat evolved.
"At length the question presents itself, where has the oxygen gone? Is there any oxygen in the jars now? We can easily ascertain this, you know by the very simple experiment of dipping into the jars respectively an ignited chip of wood. If oxygen be present, the wood will not only burn, but it will burn with great brilliancy. If oxygen be not present, the fire will be extinguished. Well, I commence with the jar in which charcoal has been burned-and observe the wood, instead of burning, is immediately extin guished. I try the same mode of testing on the remaining jars, and in every case we discover that the oxygen is no longer there. Where, then, can it have gone! you will ask. Is it destroyed? Once, and for all, banish this word from your minds,-that is to say, from your minds as philosophers. Nothing whatever is destroyed. Not even combustion itself can destroy the smallest atom. To make use of the word 'destruction' in common language is, with certain restrictions, permissible. Thus, if I burn a stick, the stick, as such, no longer exists; it is dis sipated in many gaseous forms. Yet, in these forms, disguised, still exist every atom of which the vegetable portion of the stick was composed. If I burn a candle, again, the candle, in ordinary lan guage, is said to be destroyed; but there is no destruction here any more than there was in the case of a burned stick; the elements entering into the composition of the candle are merely dispersed in various forms. And so is it with charcoal, and so is it with sulphur; the material of these bodies is, by combustion in oxygen, dispersed in the gaseous form. Not so, when phosphorus, or iron ore are burned in oxygen gas. The results of burning either of these substances are not gases or vapours, but solid bodies, which give us no great trouble to collect. On looking at the jar in which the phos