is the attraction of the basis of potash for oxygen, that it discovers and decomposes the small quantities of water contained in alcohol and ether, even when they are carefully purified. When thrown into the mineral acids, it inflames and burns on the surface. In sulphuric acid, sulphate of potash is formed; in nitrous acid, nitrous gas is disengaged, and nitrate of potash formed. When brought in contact with a piece of phosphorus, and pressed upon, there is a considerable action: they become fluid together, burn, and produce phosphate of potash. When a globule is made to touch a globule of mercury about twice as large, they combine with considerable heat; the compound is fluid at the temperature of its formation; but when cool it appears as a solid metal, similar in colour to silver. If this compound be exposed to air, it rapidly absorbs oxygen; potash which deliquesces is formed; and in a few minutes the mercury is found pure and unaltered. When a globule of the amalgam is thrown into water, it rapidly decomposes it with a hissing noise, potash is formed, hydrogen disengaged, and the mercury remains free. The basis of potash readily reduces metallic oxides when heated in contact with them. It decomposes common glass by a gentle heat, and at a red heat effects a change even in the purest glass.

In his experiments on soda, Sir H. Davy has discovered that its base, like that of potash, is white, opaque, and has the lustre of silver. The property of welding, which belongs to iron and platina, at a white heat only, is possessed by this substance at common temperatures. It is very similar in its more obvious properties to the base of potash; but it has greater specific gravity, being to that of water nearly as nine to ten, or as .9348 to 1.0000. In oxygen gas it produces a white flame, and sends forth bright sparks, occasioning a very beautiful effect. In oxymuriatic acid gas it burns vividly, with numerous scintillations of a bright red colour. In the quantity of ', it renders mercury a fixed solid, of the colour of silver, and forms an alloy with tin. When amalgamated with mercury, the amalgam will combine with other metals. Sir H. Davy tried this with iron and platina, and had reason to believe that these latter metals remain in combination with the mercury, even when deprived of the new substance by exposure to the air.

The whole of the sixth chapter of this very interesting paper is occupied with the detail of several curious and ingenious experiments to ascertain the proportions of the bases and oxygen in the two fixed alkalies; from whence concludes that 100 parts of potash consist of about 84 basis, and 16 oxygen; and 100 parts of soda consist of about 76 or 77 basis, and 24 or 23 oxygen: or that potash may be considered as consisting of about 6 parts basis, and 1 of oxygen; and soda of 7 basis, and 2 oxygen.

In reply to the question, whether the bases of potash and soda should be called metals, it might be said that they agree with metals in opacity, lustre, malleability, conducting powers as to heat and electricity, and in their qualities of chemical combination. Even their low specific gravity does not appear a sufficient reason for making them a new class; for amongst the metals themselves there are remarkable differences in this respect, platina being nearly four times as heavy as tellurium; and tellurium is not much more than six times as heavy as the basis of soda. Conceiving the bases of the two fixed alkalies to be metals, Sir H. Davy has named one Potasium, and the other Sodium; adopting that termination, which, by common consent, has been applied to other newly discovered metals.

On an examination of the volatile alkali, and after a great number of complex and tedious experiments, Sir H. Davy saw reason to conclude that ammonia contains oxygen as an essential ingredient, and that this cannot well be estimated at less than 7 to 8 parts in the hundred. After making some general remarks on the preceding facts, he suggests the probability that the muriatic, fluoric, and boracic acids, all contain oxygen as one of their constituent principles. The earths of barytes and strontian, as being most analogous to the alkalies, were likewise examined, and both yielded oxygen.

In concluding this very important communication, Sir H. Davy remarks that an immense variety of objects of research is presented in the powers and affinities of the new metals produced from the alkalies. In themselves they will undoubtedly prove powerful agents for analysis; and, having an affinity for oxygen stronger than any other known substances, they may possibly supersede the application of electricity to some of the undecompounded bodies.

In sciences kindred to chemistry, the knowledge of the nature of the alkalies, and the analogies arising in consequence, will open many new views; they may lead to the solution of many problems in geology, and show that agents may have operated in the formation of rocks and earths, which have not hitherto been suspected to exist.

These discoveries will certainly form a new era in the history of chemistry, and render the name of Davy ever dear to those who delight in the investigation of nature.

"Immortal Newton thus with eye sublime

Mark'd the bright periods of revolving time;
Explor❜d in Nature's scenes the effect and cause,
And, charm'd, unravell'd all her latent laws."

A more extended view of the connexion between electrical and chemical attraction may be seen in Sir H. Davy's Elements of Chemical Philosophy lately published, vol. i. page 158-173. See also note at page 171 of the foregoing sheets.

CHEMICAL TABLES.

Table of the Quantities of Acids and Bases which mutually neutralize each other: calculated by Berthollet from the new Tables published by Richter.

Note. The intention of this table is, that if an article in one of these two columns is taken--for example, potash-to which the number 1605 corresponds, the numbers of the other column will show how much of each acid is required to neutralize these 1605 parts of potash; viz. they will require 427 parts of fluoric acid, or 577 of carbonic acid, or 1480 of acetic acid, &c. In like manner, if an article of the second column be taken, the first column will show how much earth or alkali will neutralize it. By means of the rule of three this table may be applied to any quantity of either of the above substances.

Table of the Affinities of sundry Bases for four of the Acids, according to their Intensity.

A Table of the real Specific Gravity of Solutions as indicated by Baumé's Areometer for Salts.-Drawn up by Robert Bingley, Esq. of the Tower of London.

Table of the boiling Point of sundry Liquids, &c.

Table of the Quantity of real Acid taken up by Alkalies and Earths.-By Mr. Kirwan.

100 Parts. Sulphuric Nitric. Muriatic. Carbonic.

Table of the Quantity of Alkalies and Earths taken up by 100 Parts of real Sulphuric, Nitric, Muriatic, and Carbonic Acids, when saturated.-By Mr. Kirwan.

100 Parts. Potass. Soda. Ammo. Baryt. Stron. Lime. Magn.

Sulphuric 121,48 78,3226,05 200 138 70 57,92 Nitric 117,70 73,0340,35 178,12 116,86 55,70 47,64 Muriatic 177,60 136,20 58,48314,46 216,21 118,30 898 Carbonic 95,10149,60

354,50 231

122

50