the tendency of the science of chemistry is most exalting; at each step it implants a firm belief in the Power, and a perfect reliance upon the Goodness of God, who promised that, "While the earth remaineth, seed-time and harvest, and cold and heat, and summer and winter, and day and night, shall not cease."

The object of this essay is to adduce a few of the principal phenomena of the four seasons, which admit of explanation and illustration through the medium of chemistry; and as it teaches the composition of things, a general statement regarding natural objects and the powers unto which they are subject, will form the remainder of this introductory chapter.

The chemist, by experimenting upon the various solid, liquid, and aëriform matters, presented throughout the creation, discovers that many of them can be divided. into two or more substances of distinct and opposite characters, and that these cannot be again divided into others.

Substances that can be divided, analyzed, or simplified, are called Compounds; and such as cannot be so treated, are called Elements.

Fifty-five of these are known, all Ponderable, and subject to the agencies of Light, Heat, and Electricity, which are Imponderable. The ponderable elements are distinguished by the following names;-those marked * are Combustible and non-metallic; those marked † are Incombustible and non-metallic; the others are metallic.

1, Aluminum; 2, Antimony; 3, Arsenicum; 4, Barium; 5, Bismuth; 6", Boron; 7t, Bromine; 8, Cadmium; 9, Calcium; 10*, Carbon; 11, Cerium; 12†, Chlorine; 13, Chromium; 14, Cobalt; 15, Columbium; 16, Copper; 17, Fluorine; 18, Glucinum; 19, Gold;

20*, Hydrogen; 21†, Iodine; 22, Iridium; 23, Iron; 24, Lantanum; 25, Lead; 26, Lithium; 27, Magnesium; 28, Manganesium; 29, Mercury; 30, Molybdenum ; 31, Nickel; 32, Nitrogen; 33, Osmium ; 34†, Oxygen; 35, Palladium; 36*, Phosphorus; 37, Platinum; 38, Potassium; 39, Rhodium; 40*, Selenium; 41, Silicium; 42, Silver; 43, Sodium; 44, Strontium; 45*, Sulphur; 46, Tellurium; 47, Thorium; 48, Tin; 49, Titanium; 50, Tungstenum; 51, Vanadium; 52, Uranium; 53, Yttrium ; 54, Zinc; 55, Zirconium.

Of these elements, the following are the most abundant, and will be most frequently mentioned throughout this inquiry.

I. Combustible and non-metallic,-Carbon, Hydrogen, Phosphorus, and Sulphur.

II. Incombustible and non-metallic,-Chlorine, Nitrogen, and Oxygen.

III. Metallic,-Aluminum, Calcium, Iron, Magnesium, Potassium, Silicium, and Sodium.

The ponderable elements are capable of uniting in various ways to form a great number of compounds; and these compounds in their turn are capable of uniting with each other to form a greater number of complex compounds; and so far as the knowledge of the chemist extends, it leads him to consider that all natural and artificial objects consist of elements, and their combinations and mixtures arranged according to definite laws of weight and measure.

The term Element will occur very frequently during this examination of the principal chemical phenomena of the Four Seasons, and therefore its exact meaning demands explanation at this early stage.

The metal Iron, its tenacity, ductility, and numerous

uses, are familiar to all persons; but the chemist is not satisfied with this mere knowledge of its mechanical properties, he wishes to ascertain the composition of the metal, the things of which it consists; he endeavors to do this by making experiments; he submits iron to every process that he can devise; he alters or disguises its ordinary properties in many curious ways; but at length the metal presents itself in its original state, pure and unharmed by the ordeals through which it has passed, and without yielding the slightest clue regarding its composition.

The chemist depends entirely upon the results of 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 skillful 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 Vapor of a greenish yellow color, and the other a Solid of a silvery lustre ; he therefore terms Common salt, a Compound.

The Vapor, 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 analyzed 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 Vapor, 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 Vapor, 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 splendor.

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 splendor 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 pages 19 and 20.

The Invisible Vapor 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.