very serious consequences. The delay which has taken place in commencing legal proceedings, has not arisen from any doubt of the complete originality of the kaleidoscope, and of the defensibility of the patent. As soon as the patentee has made himself acquainted with the circumstance of the individuals who have invaded his patent, with the channels through which they have exported their instruments, and with the amount of the damage which they have done, he will seek for that redress which the law never fails to afford in cases of notorious and unprovoked piracy. We are well assured, that it never was the intention or the wish of Dr. Brewster to interfere with the operations of those poor individuals who have gained a livelihood from the manufacture of kaleidoscopes. We know that it will always be a source of no inconsiderable gratification to him, that he has given employment to thousands of persons, whom the pressure of the times had driven into indigence; and even if a decision in favour of his patent were given, he would never think of enforcing it, excepting against that class of opulent pirates who had been actuated by no other motive but the exorbitant love of gain, in wantonly encroaching upon the property of another.

The patent kaleidoscopes are now made in London, under Dr. Brewster's sanction, by Messrs. P. and G. Dollond, W..and S. Jones, Mr. R. B. Bate, Messrs. Thomas Harris and Son, Mr. Bancks, Mr. Berge, Mr. Thomas Jones, Mr. Blunt, Mr. Schmalcalder, Messrs. Watkins and Hill, and Mr. Smith. An account of the different forms in which these ingenious opticians have fitted up the kaleidoscope, and of the new contrivances by which they have given it additional value, will be given in Dr. Brewster's Treatise on the Kaleidoscope, now in the press. The public will see, from the examination of these instruments, how much they have been imposed upon by spurious imitations, sold at the most exorbitant prices, and made by individuals entirely ignorant, not only of the principles and construction of the instrument, but of the method of using it.

ÁRT. XVIII. An Account of the New Alkali lately discovered in Sweden.

THE discovery made by M. Arfwedson of a new alkali, and

announced in the last Number of the Journal, has been abundantly confirmed by the researches of other chymists. Its importance has drawn the attention of the whole chymical world, and much new information relative to its nature and its sources, has since been added, which we shall endeavour to comprise in the following account of this body.

Lithia (the name given to the new alkali) was first found in the petalite, a mineral from the mine of Utoen in Sweden. It may be obtained very readily by fusing the mineral with potash, dissolving the whole in muriatic acid, evaporating to dryness, and digesting in alcohol: the muriate of lithia being very soluble in that fluid, is taken up, whilst the other salts remain, and by a second evaporation and solution, is obtained perfectly pure.

The muriate is itself a very characteristic salt of the alkali. It may easily be decomposed by carbonate of silver, and the carbonate treated with lime yields pure lithia.

The exact quantity of lithia in the petalite is doubtful, bat it cannot contain much more than five per cent. A more abundant source has however been found in the Triphane or Spodumene, which according to M. Arfwedson, who also first pointed out in it the existence of lithia, contains eight per cent. of the new alkali. The same chymist has likewise ascertained its existence in another mineral from Utoen which is called crystallized lepidolite in the proportion of four per cent.

The pure alkali is very soluble in water, has a very acrid caustic taste, like the other fixed alkalies, and acts powerfully on blue vegetable colours. When heated on platinum, it acts on it. It has a strong affinity for acids, and a very high neutralizing power, even surpassing that of magnesia. Its solution precipitates the earthy and metallic salts, nearly as solutions of the other alkalies do.

Placed in the Voltaic circuit, Sir H. Davy showed that it

was decomposed with the same phenomena as the other alkalies. A portion of its carbonate being fused in a platinum capsule, the platinum was rendered positive and a negative wire brought to the upper surface. The alkali decomposed with bright scintillations, and the reduced metal being separated, afterward burnt. The small particles which remained

a few moments before they were reconverted into alkali, and allowed a short examination, were of a white colour, and very similar to sodium. A globule of quicksilver made negative, and brought into contact with the alkaline salt, soon became an amalgam of lithium, and had gained the power of acting on water, and evolving hydrogen, an alkaline solution resulting.

The chloride of lithium obtained by evaporating the muriate to dryness, and fusing it, is a white semi-transparent body, analogous in its appearance to the chlorides of potash and soda, but very different from them in its general properties. It is extremely deliquescent, whereas they are not so in this respect it almost equals muriate of lime. Its solution crystallizes with great difficulty, but by evaporation affords minute needle-form crystals. It is very soluble in alcohol, but the chlorides of potash and soda very little so. Its solution, or the moist salt, has the property of tinging the flame of alcohol of a fine red, somewhat like strontian, but the other alkaline muriates have not this power. It fuses below a red heat, and when heated powerfully in the open air, it gradually loses chlorine, absorbs oxygen, and becomes strongly alkaline.

All its salts are very fusible, but in some cases a singular degree of insolubility belongs to them. The nitrate is a very soluble salt, deliquescent, and capable of crystallizing in rhomboids. It has a very aigre taste: heated it readily fuses, and is then decomposed with the same phenomena as nitre.

The sulphate of lithia is a salt which crystallizes readily in small rectangular prisms; they are perfectly white, and possess much lustre; have a saline taste, very different to potash or soda; are more soluble in water than sulphate of potash;

perhaps not so soluble as sulphate of soda: the crystals contain no water; they fuse and become very liquid below a red heat; their solution does not precipitate the muriate of platina, nor is it precipitated by tartaric acid. M. Vauquelin gives an experiment on its constitution, the result of which is as follows :* Sulphuric acid Lithia

69.18

30.82

100.00

The sub-carbonate of lithia is but little soluble in water, and effloresces in the air. It may even be precipitated from its sulphate by adding a strong solution of carbonate of potash to it. It is readily fusible, and when fused, requires repeated additions of water with boiling to dissolve it again. Cold water dissolves about one one-hundredth part of its weight of this salt, and the solution acts powerfully on vegetable colours and effervesces with acids. According to Vauquelin, it attracts carbonic acid very rapidly from the atmosphere.

The carbonate, heated on platinum, acts on it almost as powerfully as the fixed alkaline nitrates. It separates ammonia from its combinations, but is decomposed by lime and barytes, and rendered caustic.

The solution of the carbonate precipitates the muriate of Jime, the sulphates of magnesia and alumina, and the salts of copper, silver, and iron, just as the other alkaline carbonates do; but it does not precipitate the muriate of platinum, as is the case with the sub-carbonate of potash.

The tartrate of lithia is an efflorescent salt; the acetate one that on being evaporated, takes the state and consistence of gum or syrup.

The sulphuret formed by M. Vauquelin, appeared in all respects, similar to the fixed alkaline sulphurets; except in the larger proportion of sulphur thrown down by acids.

There is an error in the calculations in M. Vauquelin's paper, the given constituents of 100 parts, if added together, making 101. The proportions deduced from the experiment, are correctly as above, at least to the second decimal place.

With respect to the proportions of the elements of the alkali, they do not appear exactly determined. Mr. Arfwedson states, that lithia contains 43.9 per cent. of oxygen. M. Vauquelin concludes that it contains 43.5 per cent.; but in consequence of the error mentioned in the preceding note, the last number is not correct, and if deduced from that experiment, the oxygen would be 44.84 per cent.

ART. XIX. Observations relating to the Operations undertaken to determine the Figure of the Earth. By M. Biot, of the Academy of Sciences.

THE distinguished author of this pamphlet, which has just

been published in Paris, is too favourably known to our scientific readers, to require any introduction or eulogy, and the subject he treats of is so well set forth in a preceding article of this Number of our Journal, by an eminent foreign correspondent, that we can find little to add from the present pages. Our task on the present occasion, is the most grateful we have ever had to perform-that of recording a manly and liberal avowal of the hospitable reception which the author found upon our shores, a just tribute of applause to the scientific eminence of our countrymen, and a most liberal acknowledgment of the assistance which he received in his important philosophical investigations. We hope that this paper will be received as a record of the amity which really exists among the men of science of the two countries, and of their honourable inclination to avow and protect it from the gales of political animosity. We trust too, that it shows a desire in the high quarter whence it comes, of duly acknowledging the merits, value, and originality of British talents, as opposed to the paltry and absurd jealousies which have more than once been suffered to stain the pages of continental writers.

In the following animated exordium, which it would be wrong