experiments for his knowledge, and in the above instance, he has no alternative but to make a candid confession of his inability to prove of what things Iron consists; and, in accordance with the principles of inductive philosophy, he is obliged to call the metal a Pure, Undecompounded, or Simple substance, a Rudiment, or an Element.

In employing this term he wishes to be distinctly understood, that he does not presume to say that Iron must be absolutely simple or undecomposable, because he is not sufficiently skilful to discover its composition; he merely wishes to express, that he cannot experimentally prove it to contain two, or more substances, or in other words, that he cannot prove it to be a Compound, and in this sense no objection can be made to the term Element.

The substance called Common-salt, and its important uses as a preservative of food, are universally known and appreciated; but the chemist wishes to know of what things Common-salt consists.

"TRY," is the motto of the laboratory; and accordingly, by trials or experiments, the chemist soon discovers that he can divide Common-salt into two new and distinct substances, one of them a Vapour of a greenish yellow colour, and the other a Solid of a silvery lustre; he therefore terms Common-salt, a Compound.

The Vapour, he terms Chlorine, in allusion to its peculiar tint; the Solid, Sodium, to denote its identity with that obtained from a plant called the salsola soda;

and as these are the only two substances obtained by the analysis of Common-salt, he terms it Chloride of Sodium, to express its constitution with precision.

But the chemist is now only half satisfied, he has another question ready :-Of what does Chlorine consist, and of what does Sodium consist?

He again appeals to accurate experiment; but he finds that neither Chlorine nor Sodium can be analysed or simplified, they remain refractory as the metal Iron, they demand to rank with it as Elements, and this position the chemist is reluctantly compelled to grant.

Chalk is another well-known substance ;-Of what does it consist, is the question of the chemist: is it an Element like Iron, or is it a Compound like Salt?

The chemist discovers that Chalk will immediately relinquish two new substances, one of them an Invisible Vapour, and the other a White Solid; he therefore terms Chalk, a Compound. But the chemist is not contented with this result; he again puts the question,-Are these new substances elements or compounds?

Although one of the substances is an Invisible Vapour, it can be confined, weighed, measured, and experimented upon with the utmost facility; and when the chemist submits it to his most refined operations, it yields two new substances, the one an Invisible Gas, and the other a Black Solid; whilst the analysis of White Solid, yields the same Invisible Gas, and a Solid of Silvery splendour.

These new substances now require to be denoted by names; the chemist finds that the Invisible Gas has the power of producing many Acids, and therefore he calls it Oxygen; the Black Solid he discovers to be the pure inflammable principle of Coal, and therefore he calls it Carbon; whilst the Solid of Silvery splendour he discovers to be a constituent of Lime, and therefore he calls it Calcium.

He generally draws upon the rich stores of the Greek and Latin languages, for names to denote the various substances that he obtains; and this will be evident upon reference to the list of elements, at page 4.

The Invisible Vapour obtained by the chemist during his first experiments upon Chalk, proves to be an Acid compound of Oxygen and Carbon, and to denote this fact, he calls it Carbonic acid; whilst the White Solid substance proves to be an Alkaline compound of Oxygen and Calcium, and therefore he calls it Oxide of calcium, or more familiarly, Lime.

The composition of Chalk, in refined chemical nomenclature, is accordingly expressed by the term Carbonate of oxide of calcium; but the chemist, for brevity, generally calls it Carbonate of lime; it is a compound of two compounds, and these he familiarly calls its Proximate elements, because they immediately come forth, upon the first, or proximate analysis, and they will, under certain conditions, immediately unite and reproduce chalk.

On the other hand, Oxygen, Carbon, and Calcium, into which Carbonic acid and Lime are resolvable, do

not admit of further analysis or simplification; they are refractory like Iron, Chlorine, and Sodium, and therefore the chemist calls them Ultimate elements, meaning by the term, elements elicited when analysis is carried to its utmost possible extent.

The union of two or more Ultimate elements, constitutes a Primary combination; and that of two or more Proximate elements, a Secondary combination; and as the chemist, throughout all his researches, is guided by a constant appeal to a just and delicate balance, he discovers that each kind of combination is governed by a definite weight.

For example, if he experiment upon 1000 parts by weight of Chloride of sodium, he will invariably obtain 600 parts of Chlorine and 400 parts of Sodium ; if upon 1000 parts of Carbonate of lime, he will first obtain 440 parts of Carbonic acid, and 560 parts of Lime; if he pursue the ultimate analysis of these com pounds, he will obtain from this quantity of Carbonic acid 320 parts of Oxygen, and 120 parts of Carbon; and from the Lime, 160 parts of Oxygen, and 400 parts of calcium.

If the chemist, by well-known agents, excite the above substances to combine as Primary, or Secondary compounds, they will only do so in such weights, he has no power of forcing them to combine according to his caprice; a grand and immutable law of Definite weight presides over every analytical and synthetical operation.

Chemistry, thus tending to the discovery of the

66

elements of things, and of the laws by which they are controlled, presents its votary with powerful illustrations of the Truth, that a just weight and measure are the Lord's;" that "a just weight is His delight;" that "He comprehended the dust of the earth in a measure, and weighed the mountains in scales, and the hills in a balance."

The chemist endeavours to act as the humble and faithful interpreter of the wonders of the Creation, and everywhere discovers proofs of the power and goodness of God: what a glorious contrast does this exalted occupation present, to the sordid pursuits of the darker ages, when the transmutation of metals, and the production of an elixir of immortality, formed the vain and presumptuous hopes of the experimenter!

Throughout the Four Seasons, it must be obvious that Air, Water, Earth, and Heat, are ever active and important agents, and therefore a general account of their chemical habitudes demands a place in these introductory pages, to facilitate our future proceedings.

The science of chemistry is founded upon the laborious yet certain practice of EXPERIMENT, and by its aid the Air, or Atmosphere, is proved to consist chiefly of two elementary gases, named Oxygen and Nitrogen; they are strongly opposed in their chemical characters, for the former will support life, and flame, for a time, but the latter will destroy both, instantaneously.

The chemist can combine Oxygen and Nitrogen, in