The mushroom is a very scarce vegetable in our markets, except for a very short season, and it is a great pity for it is a great luxury.

Few people seem to have acquired a taste for it, perhaps from its scarcity, but I think the time is not far distant when a bottle of nice mushroom catsup will be considered a necessary condiment on every farmer's table. The prevaling opinion seems to be, that there is something very mysterious in growing them; and a great many people do not know how to distinguish between an edible mushroom and a poisonous toadstool.

I may be told th?y are a luxury that can be done very well without; to which I answer: So was tea in the time of our forefathers. But who would like to part with tea now? The mushroom only requires to become well known and its management properly understood, to be appreciated; and when it does, it will become almost a necessity, like many other blessings we now enjoy. Most good gardeners I believe grow them, but it is chiefly for private families.

When the farmers begin to grow them they will be found a profitable crop, their use will become general, and they will be found plenty in our markets. I do not wish to go over the ground already gone over so often by others, but to show in what I differ with them, what additions I have made (improvements, if you wish), and how easily they can be grown in abundance by any one who wishes to take a little trouble in the matter. There are many works, I believe, written on the the subject, which I have not seen, but what is here given is the result of many years' practical experience.

In the first place 6o° is about their mean temperature. It will readily be seen that they do not need a hot-bed in any of the summer months. A dry cellar, built of brick or stone, is best adapted to their growth in this climate, but an arched cellar built in a bank, with its end facing to the south, is peculiarly adapted to them. Little flat beds on cellar floors, made up of proper materials, will give abundant crops all summer and fall without artificial heat. A little light and a little air is necessary for wholesomeness' sake. In the next place, wood of any kind, especially pine, should never surround the beds when made on the ground; but the beds should be built up against the wall with a few bricks in front to keep the materials together. Common house slates, sunk in the beds, perpendicular to the wall and on their edges, about two feet apart, to half their depth, will obviate the necessity of watering in a great measure. These will be found dripping with water nearly at all times - by the wall, by the bricks, and by these slates, they will be found very often more plentiful than on other parts of the bed. But a successful crop bears all over the face of the bed in the greatest profusion. To have a successful crop, abundance of spawn is at all times needful.

It is well known that mushroom spawn breeds, or originates in materials adapted to it; but many people will scarcely believe that a bed made up of proper materials, will, after five or six months, yield a plentiful crop without having been planted with spawn. However, it is not till after this spawn has bred plentifully in the bed, it begins to bear. It is not my intention to philosophize or go into elaborate details of what spawn is, but to enter at once into the practical part of the business. It is admitted by all that fresh maiden earth from under an old sod, or sods of an old pasture rotted well down, clean, and free from weeds, is the best kind of soil to earth over the beds with. Lime, old or new, is excellent in their compost, and oystershell lime by far the best of any. Old, dry, turfy peat, not that from a swamp, or in any way sour, is excellent in their compost.

There are different methods of originating mushroom spawn, but the droppings of horses highly fed, is considered the best or one of the best materials to work with. The droppings of horses out on grass will not do.

To originate spawn and have plenty at all seasons, let boxes of almost any convenient size be got ready and filled alternately with layers of dry horse droppings and red or yellow clay well dried. Old bricks pounded up fine are best. One inch of clay or brick dust, and three or four inches of the horse manure is about right; and when the boxes are full let them be well trodden down - the harder the better - and put in a warm place. Good, natural spawn will breed in these boxes in about four or five months; but if a few pounds of spawn bricks be bought at any seed store, broken up into small lumps and placed in the center of these boxes, they will be full of good spawn in about one-half the time. After a few boxes of spawn have been generated in this way, it can be increased to any amount very soon by mixing some into other boxes of droppings, and in this case no earth need be put in the box.

It may be well to have a stock of spawn bricks on hand, for they will last many years if kept dry and in a warm place. I agree with the mode of making them, as recommended in the different garden books, but there is no need to impregnate them in the old way, but place them in a conical pile, or any convenient way, and between every layer of bricks put a layer of spawn from the boxes. Cover up well with straw in summer, or warm horse manure over the straw in winter, sufficient to throw a gentle heat into the pile, and after about four or five weeks the whole pile will be one solid mass of mushroom spawn. The place where mushrooms grow should be free from underdamp and noxious vapors. Straw covering is preferable to hay, as wet hay lying on the bed breeds noxious fungi, which would soon destroy the whole crop. To make a bed is a simple process when properly understood. Most people take too much pains, and this is the cause of many failures. But one thing is certain - they are greedy feeders, and must be well fed to have a good and lasting crop. Flat mushroom beds are recommended to be made of three or four-inch courses of dry hiorse droppings, with two-inch courses of earth between them; but these beds I found to soon run out and get too dry.

Therefore, let about three inches of old, soft, unctious manure be placed at the bottom of the bed in every case, with a small layer of earth underneath about half an inch thick, then one inch of earth on top and well trodden down. Then about three inches of droppings with a good coat of spawn from the boxes; then another layer of droppings, and all well trodden down and left for two or three weeks, or till the spawn has begun to run all through. Then, and not till then, must the last coat of earth be put on, which is best made up of three parts maiden earth and one part turfy peat, with a good sprinkling of oyster-shell lime through it, laid on two inches thick and well trodden down, afterwards smoothed very hard with the back of a spade. Then covered up with straw till a white mold covers the bed and mushrooms all over, like peas thickly scattered, when the straw may be taken off altogether. This is only one of about a dozen ways; but in all cases the old rich manure must be at the bottom. It must have been turned several times to sweeten and partly dry before it is used.

These are a few of the principal points to be attended to.

There is one thing I wish particularly to mention to all who grow mushrooms, that is, to beware of salt. Dirty salt is often thrown out of horse and cattle mangers and gets mixed up with the manure. The smallest quantity of this will render a mushroom-bed unfruitful. This is the true key to the theory of throwing salt over grain crops in the spring of the year, which every farmer does, or ought to do, to keep down and kill rust, smut and mildew, and every other species of fungi. Besides, salt kills worms, grubs and numerous insects injurious to grain crops, and I believe is a good absorbent of moisture, as well as a good manure.

Mr. Editor, I believe this article is already too long, and in trying to be brief I may have become obscure. If you think any more is wanting to this article I will be happy to communicate.

Chambersburg, Trenton, N. J.