orable service, when all the vegetable forces are disbanded by the dissolution of the organic compound.

The chief productions of the decomposition of muck are carbonic acid and water. But these are the results of the combustion of wood and coal, or any vegetable substance. This decomposition is really a combustion, and differs only from ordinary combustion in its slowness and the absence of the evolution of light. Heat is produced as truly as in ordinary combustion. A given quantity of carbon in becoming carbonic acid, produces precisely the same amount of heat whether the combustion be rapid or slow. Vegetable matter decaying in the soil must, therefore, be a constant source of heat in the soil. We have already seen that muck, by absorbing the solar rays, becomes a means of warmth to the soil. Here we see it is a source of heat of itself. In both ways then, it tends to give a warmer soil.

By this decomposition it also becomes a constant source of carbonic acid in the soil. This is a matter of great importance. Certain elements exist in the soil that are very necessary for the growth of plants, but which are entirely insoluble in pure water. I will only mention carbonate and phosphate of lime. Undissolved, they cannot enter the circulation of the growing plant, and are entirely inert. Both these substances are dissolved by water containing carbonic acid, and are thus fitted to supply the wants of the growing plant. Not only can absorption take place, but the area of absorption is remarkably increased by this solution. Absorption can take place only at the surface of substances, for the delicate spongioles of plants have not the power to force themselves into the substance of those hard minerals. A cubic inch of carbonate of lime has a surface of six square inches, but when it is dissolved, it is estimated that the particles in solution are less than inch

1

500,000

in diameter. If this is true, a cubic inch in solution would expose an absorptive surface of more than 20,000 cubic feet, in stead of six square inches!

Carbonic acid, in its nascent or formative state, is the great

agent by which the hard minerals composing the soil are slowly decomposed, and their elements furnished in a state fitted to supply the wants of the growing plant.

It may seem that the slow and feeble influences of such agents as carbonic acid and water can effect but little, and may be safely left out of the account; but it is not so. It is by slow and feeble agencies, acting silently but continuously and irresistibly, that nature effects her wonderful transformations. It is by the slow addition, atom by atom, of carbonate of lime, by a microscopic insect, that the coral, "the adorner of the sea," lifts his palace from the ocean bed to the surface. It is by the slow attrition of heat and cold, of moisture and chemical change, that the rocks are ground to dust and the mountains are slowly leveled to the plain.

"The mills of the gods do slowly wind,

But they to dust do all things grind."

From all the properties enumerated; from its mechanical influence on the tenacity of soils, rendering the heavy soil lighter and the light soil firmer; from its relations to heat and to moisture; from its power of absorbing and retaining the soluble parts of manures and the salts essential to vegetable growth, and from the effects produced by its slow decay in the soil, it is evident that muck may be a substance of great value in our system of agriculture. Where it is properly prepared and judiciously applied, it will be beneficial to all lands which are not already abundantly supplied with vegetable mould.

Muck also contains a large amount of mineral matter, which remains as an ash when the muck is burned. This ash varies both in quantity and quality according to the circumstances under which it was found. It constitutes from 4 to 12 per cent. of its weight when dry. A rough analysis is here given of the ash furnished by burning muck from the bed near the large barn on the College farm:

The per centage of the ash soluble in dilute Hydrochloric Acid was therefore nearly 55 per cent.

III. METHODS OF USING IT.

Before detailing the methods of using muck, I will say a few words upon the means to be employed to change cheesy and pealy muck to powdery muck. It is only this last variety which is fit for immediate application to land. The cheesy muck is too tenacious, and it often contains free acids-it is popularly and properly called "sour," and in this condition it is injurious to land.

It becomes a matter of importance how to change this cheesy variety into powdery muck. This is best effected by exposure to frost and air. By the action of the frost the cohesion of the muck is destroyed and it becomes pulverulent, and by the access of air the acids of the muck are neutralized by the ammonia in the atmosphere. In popular language, frost sweetens muck." The frost reduces it to a powder, but it is the ammonia that neutralizes its acids and "sweetens" it. Throw it up in long rows, so that the frost may thoroughly penetrate it, and the superabundant moisture may flow off, and let those wonderful chemists, air and frost, apply their subtle reagents night and day all winter long, and in the spring, instead of the crude sticky mass, you will have fine powdery muck.

The peaty variety is so slow in its decomposition as to be nearly worthless, except for mulching. By protracted exposure it may be changed into the powdery condition, but it is doubtful if it will make so good a product.

Muck, when sufficiently acted upon by air and frost, is useful as a top-dressing for meadows where the supply of vegetable matter in the soil is insufficient; also, to be plowed under in soil which is deficient in vegetable mould. All fertile soils are found to contain a certain quantity of vegetable matter. Although plants can grow in a soil entirely destitute of vegetable matter, yet they make a feeble and sickly growth. Vigorous vegetation, such as every farmer would wish to see, only thrives where a certain per centage of vegetable mould is present in the soil. The action and benefit of this vegetable mould have already been pointed out.

The most important use of muck is as an absorbent in the compost pile, &c. Animal manures are liable to loss from the formation and escape of volatile matters in the manure heap, as for example ammonia, sulphuretted and phosphuretted hydrogen, and the strong smell of hartshorn or ammonia perceptible around every pile of fresh horse manure, is proof of this; or by the leaching and washing away of the soluble salts by rains, as is shown by the dark streams so often seen flowing from barn yards after a shower; or by excessive decomposition or fire-fanging," as it is commonly called.

Properly composting manures with muck will prevent all these sources of waste and loss. The muck has such a strong affinity for ammonia and the other volatile gases, that where it is mixed with substances yielding these by their spontaneous. decomposition, it will absorb all of these volatile products and prevent all loss. We have seen, also, that it has such a strong tendency to absorb the salts found in manures, that it will take them all out of solution when filtered through muck. This must convince any one that composting with muck will prevent all leaching, and thus loss by these two methods is entirely prevented by the absorptive property of muck.

Loss by the third means, "fire-fanging," is incurred when manures are exposed to the action of the air in such quantity and in such concentration that excessive chemical reactions take place, equivalent to a species of combustion, when in

popular language the fire has struck its fang into the pile, or it is "fire-fanged." This is all prevented by intimately mixing the manure with some inert matter, as muck, which will so far dilute the fermenting mass as to moderate and control the chemical reactions, keeping the temperature within safe bounds, and thus preventing loss.

Not only will the manure thus be saved from loss but, where equal parts of manure and muck are used in the pile, the compost will be equal, load for load, to the best short or well-rotted manure. Thus the farmer will practically double the quantity of manure on his farm by composting.

Nor is this the only advantage. Most of the noxious seeds contained in the green manure, will germinate in the compost heap, but will soon die in consequence of the pile being frequently turned or shoveled over. Thus the spread of the Canada thistle, dock, red root, &c., will be prevented to a large

extent.

Again, by the use of muck as the composting agent, many substances, of remarkable fertilizing power, but which are frequently rejected on account of their offensive odor, may be added to the compost heap. Dead and putrefying animals, which are so often drawn off to the woods or buried in the ground, may be safely committed to the compost pile, and if kept well covered with muck will give off no offensive odors.

There is one other kind of manure which, on account of its offensive odor, is very generally neglected, but which when composted with muck, loses all its bad smell, is as agreeable to handle as any other kind of manure whatever, and is a very rich and valuable addition to any soil. I refer to human ordure or "night soil." This substance contains a large per centage of the salts of potash, soda, lime, the compounds of nitrogen, and especially phosphoric acid. It is, therefore, very rich in the most desirable and costly elements of vegetable growth. The only reason why it is so generally neglected is prejudice on account of its offensive odor. But whenever it is thoroughly mixed with muck, this disagreeable odor disappears entirely.