translated from the Annales de Chimie, in the Quarterly Journal of Science for 1826.

Why are vitreous tubes occurring in elevated sandy districts, called "lightning tubes ?"

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Because they have been considered as produced by lightning, which melts the sand to a considerable depth, so as to form a tube, commonly sinuous, with solid and smooth walls internally, and rough on the outside. In 1828, a young German naturalist presented to his academy some of these tubes seventeen feet in length. It has been asked how electricity could produce effects so intense, and which have been considered so different from those obtained from artificial electricity; but this point has been decided by two eminent French chemists' success in forming fragments of tubes perfectly resembling the natural lightning tubes, only that their walls were less solid, and their length less.

Why have the gymnotus, or electric eel, and the torpedo, or electric est, a benumbing effect when touched?

Because of certain singularly constructed organs given to those remarkable animals for the purposes of defence, which certain forms of the Voltaic apparatus much resemble; for they consist of many alternations of different substances. These electrical organs are much more abundantly supplied with nerves than any other part of the animal, and the too frequent use of them is succeeded by debility and death.—Philosophical Transactions, 1817.

Towards the close of his valuable life, Sir H. Davy dated from Lubiana, Illyria, (1828) an important paper containing a summary of his experiments on the torpedo. It will be found in the Philosophical Transactions of the year. Among the inferences drawn by Sir Humphry, is "a stronger analogy between common and animal electricity, than between Voltaic and animal electricity; and a probability that animal elec

tricity will be found of a distinctive and peculiar kind.” This opinion, it will be perceived, is at variance with the explanation quoted in the preceding paragraph. Again, Sir Humphry observes, "the organ of the torpedo depends for its powers upon the will of the animal. John Hunter has shown how copiously it is furnished with nerves. In examining the columnar structure of the organ of the torpedo, I have never been able to discover arrangements of different conductors similar to those in galvanic combinations; and it seems not improbable that the shock depends upon some property developed by the action of the nerves."

Why do vegetables tend to atmospheric electricity ? Because of the action of the charcoal they contain upon the oxygen of the air; and when it is considered that on one hand about fifteen grains of charcoal, in becoming carbonic acid, gives out sufficient electricity to charge a Leyden jar; and, on the other hand, that the charcoal which is contained in vegetables does not give out less electricity than charcoal which burns freely, one may conclude, as direct experiments tend to prove, that over a surface of vegetation, 100 metres square, more electricity is produced in a day than is necessary to charge the strongest electrical battery.— M. Pouillet, in the Annales de Chimie.

Why is electricity beneficial to plants?

Because electrified seeds pass more rapidly through the first periods of vegetation, than such as are not electrified; and electrified roses flower more rapidly and abundantly. Plants with pointed leaves and spines attract electricity.

Why is the cutting down of forests found to diminish the quantity of rain?

Because it is supposed to diminish the attraction for clouds.

Why do leeches die suddenly at the approach of or during storms?

Because of the coagulation of their blood, caused by the impression of the atmospheric electricity.

Why is electricity considered an important chemical agent?

Because it not only produces an infinite variety of changes, but likewise influences almost all which take place. Thus, there are not two substances on the surface of the globe that are not in different electrical relations to each other; and chemical attraction itself seems to be a peculiar form of the exhibition of electrical attraction; and wherever the atmosphere, or water, or any part of the surface of the earth gains accumulated electricity of a different kind from the contiguous surfaces, the tendency of this electricity is to produce new arrangements of the parts of these surfaces; thus, a positively electrified cloud, acting even at a great distance on a moistened stone, tends to attract its oxygenous or acidiform, or acid ingredients, and a negatively electrified cloud has the same effect upon its earthy alkaline, or metallic matter; and the silent and slow operation of electricity is much more important in the economy of nature, than its grand and impressive operation in lightning and thunder. The chemical agencies of water and air are assisted by those of electricity; and their joint effects, combined with those of gravitation, and certain mechanical ones, are sufficient to account for the results of time.-Sir H. Davy's Consolations in Travel.

Why are magnetism and electricity, which had long been studied as separate branches of science, now effectually blended?

Because all the phenomena of magnetic polarity, attraction, and repulsion, have at length been resolved into one general fact, that two currents of electricity moving in the same direction repel, and in contrary directions attract, each other.-Herschel.

Hence, the magnetic effects of electricity constitute a new branch of science, under the title of electro

magnetism. The more popular phenomena of magnetism, which it will be our object to explain, do not, however, belong strictly to chemical inquiry; we may therefore reserve their illustration for a more fitting occasion.

LIGHT AND FLAME.

Why may light and air be said to constitute a portion of our earth?

Because of their absorption by the earth. Thus, the light emitted by burning coals, (which are generally admitted to be of vegetable origin) has undoubtedly been condensed in them by a process of nature which bids defiance to conjecture.-Mr. Detrosier of Manchester.

Why does a fire give out warmth?

Because the heat is radiated; there being but little connexion with the immediate conducting power of the air; thus, if a concave metallic mirror be held opposite the fire, a heating and luminous focus will be obtained. Why is ice produced in India (as described in page 34)?

Because, chiefly, of the high radiating powers of the dry straw which is strewed in the inclosures, containing the water in shallow dishes. Calm and serene nights are most favourable to this operation, and it is necessary that the straw should be dry; for, when wetted, the production of cold is prevented; a circumstance which shows that evaporation is not the cause of the diminished temperature. We quote this from Brande, although the conclusions do not coincide with the opinion quoted from Arnott, at page 33.

Why are certain rays of the sun termed decompos

ing ?

Because they have a tendency to interfere with the chemical constitution of bodies. Besides this kind of rays, it is ascertained there are two others; the calori

fic, or heating rays; and the luminous, or colourific rays, which produce vision and colour.

Sir H. Davy has, in some general facts of great interest, traced an analogy between the effects of the sun's rays and the agencies of electricity.

Why are the terms red-hot and white-hot used?

Because, when bodies are rendered luminous by great elevation of temperature, the light which they emit often appears dependent upon the heat to which they are subjected. There are, however, certain bodies which, at high temperatures, are remarkable for the quantity and extreme brilliancy of their light, independent of actual combustion; this is the case with several of the earths, but more especially with lime, a small ball of which, about a quarter of an inch in diameter, being ignited in the flame of alcohol urged by oxygen gas, emits light; having about thirtyseven times the intensity of an Argand lamp burner.Brande.

Lieutenant Drummond has proposed to apply this principle to the improvement of the illumination of light-houses; by substituting "for the Argand burners a small ball of lime ignited by the combustion of oxygen and hydrogen." His experiments are described in the Philosophical Transactions, 1830, as follows:

"From this small ball, only three-eights of an inch in diameter, so brilliant a light is emitted, that it equals in quantity about thirteen Argand lamps, or 120 wax candles; while, in intensity or intrinsic brightness, it cannot be less than 260 times that of an Argand lamp. These remarkable results are deduced from a series of experiments made lately at the Trinity House; and, having been repeated with every precaution, and by different individuals, there seems no reason to doubt their accuracy. In the best of our revolving lights, such as that of Beachy Head, there are no less than thirty reflectors, ten on each side. If, then, a