There is nothing in the able Report of the Board of Health, of more horticultural importance than the evidence collected on the mode of applying liquid manure. Not that it contains anything new upon the subject, but because what it does contain is well put, and ably illustrated. Our own columns bear ample testimony to the difficulty of impressing upon the minds of gardeners the extreme importance of employing such fluids in a state of great dilution; for, notwithstanding our repealed warning!, and the wise practice of their neighbors, men are still to be found so unintelligent as to insist upon using strong liquid manure. " How strong may I make it?" says one correspondent. "Of what use is it,if it be weak?" writes another. " Why can't I put on plenty at once, instead of being always at it?" demands a third. In vain we advise, in vain point out reasons; we find the same class of questions incessantly repeated. Let us hope that the following quotation from the Report before us will assist in dispersing the mistiness which still hovers over some portions of the horticultural mind:

" Sir Joseph Paxtoh collects at Chatsworth the manure water from water-closets, horse-dung linings, and various other sources, into large covered tanks; the waste also from a small bath is emptied into one of these, by which means the solution becomes very thin. The liquid so collected passes almost immediately in to a state of incipient or partial decomposition, arid thus becomes fit for the food of vegetation; when drawn off for use, it is always greatly rfi-luted with water, and never supplied except when the plants are in a state of activity and growth; otherwise he considers the effects would in many cases be prejudicial, rather than otherwise. It is used by him liberally to vine borders, peach trees, melons, cucumbers, pines and other fruits, with the most powerful and satisfactory results; in fact, the use of plant food in a liquid state, if properly prepared and ad ministered, supersedes in a great degree, the necessity for manure in a solid form; and the produce in favor of the liquid greatly preponderates, being both larger in quantity and weight, richer in color, and superior in flavor.

" These advantages, however, could not be secured with certainty, unless the solution were so prepared as to suit the habits and requirements of the various plants to which it is sup-Slied. This preparation is of two kinds: - first, by diluting the liquid sufficiently with water to prevent the spongioles of roots becoming glutted with too great a supply of food; and, secondly, rendering it of a proper temperature by the addition of hot water. Pines require the liquid at about a heat of 80° Fahr., and other plants in proportion; fruit trees, and other open air product*,, however, do not necessarily require the addition of hot water to the same ex tent as in-door produce, hut are, notwithstanding, much benefitted by receiving it in a moderately warm state. Wherever a steam engine is employed, Sir Joseph Paxton's practice of artificially warming the liquid manure, might be easily adopted, by allowing some of the waste steam to blow through the tank or pipe. Experience lias, however, amply shown, that for ordinary crops, sewerage in its usual state is the most valuable manure that has yet been introduced.

" By attention chiefly to the prefer administration of liquid food, and other suitable appliances, the Pine-apple, a plant formerly considered of so slow a growth as to require three years before it could produce full sized fruit, bas, by Sir Joseph, been so hastened in its growth, as to yield, within an average of fifteen months, a far greater supply of finer fruit than was formerly produced by three years1 expense and labor. From every day's experience, an instance or two out of a multitude might be cited by way of illustrating that even a much shorter period than fifteen months, is not unfre-quently sufficient to accomplish all that could be .desired. An ordinary sucker of a Provi-dence Pine was detached from the old stock during the month of March, and was planted out in a prepared bed of soil in a pit, and in the following August it produced a ripe, well-grown fruit, weighing 8 lbs. Two suckers, also, of a Cayenne Pine were separated and planted out in April, and in the following September one of them produced a fruit weighing 7 1/4 pounds, and the other one 8 pounds. A large pit or Cayenne suckers of various sizes, were planted out in a pit last spring, and in the autumn, the fruit, when ripened, gave an average of one pound in weight, for every month the plants had grown.

These were not isolated or extraordinary instances of early production, but the common and natural result of this system of culture, which stimulates to extraordinary growth, and the most perfect development. The effects of liquid manure, when applied to the roots of vines in pots, and on rafters, and to cucumbers and melons, are equally apparent; the leaves assume a rich deep color, become large and spreading, the growth is rapid and healthy, and the produce is invariably fine, plump, and becomes quickly matured".

In all this statement there is nothing except what every intelligent gardener can confirm especially those parts printed in italics. The whole art of liquid manuring, is, in fact, comprehended in the foregoing extract.

Let the manure be extremely weak; it is idle to ask how weak; liquid manure owes its value to matters that may be applied with considerable latitude; for they are not absolute poisons, like arsenic and corrosive sublimate, but only dangerous when in a state of concentration. Gas water illustrates thiesufficiently well; pour it over a plant in the caustic state in which it cornea from gas works, and it takes off. every leaf, if nothing worse ensues. Mix it with half water - still it burns; double the quantity once more - it may still burn, or discolor foliage somewhat; and if it does not, much of what falls upon a plant is necessarily lost. But add a tumbler of gas-water to a bucket full of pure water, no injury whatever ensues; add two tumbles full, and still the effect is salubrious, not injurious. Hence it appears to be immaterial whether the proportion is the hundredth or the two hundredth of the fertilising material. Manuring is, in fact, a rude operation in which considerable latitude is allowable. The danger of error lies on the side of strength, not of weakness. To use liquid manure very weak, and very often, is, in fact, to imitate nature, than whom we cannot take a safer guide.

This is shown by the carbonate of ammonia carried to plants in rain, which is not understood to contain, under ordinary circumstances, more than one grain of ammonia in one pound of water; so that in order to form a liquid manure of the strength of rain water, one pound of the carbonate of ammonia would have to be diluted with about 7,000 pounds weight of water, or more than three tons. Let us not be misunderstood. We do not mean to say that any such dilution as this is absolutely necessary; we only point to the very significant fact, that in the operations of nature, dilution is enormously beyond what cultivators usually dream of.

Let such manure be applied only when plants are in a growing state. In addition to Sir Jo-beph Paxton's evidence, and to the general notoriety of this rule, may be usefully added a statement made by Mr. M itchell, Lord ELLES-here's gardener, and quoted by the Board of Health. This experienced cultivator says - "That he has never seen any manure produce so good a crop of strawberries as the liquid (1. e. town or sewer manure,) has this year done at the Worsley Hall gardens. Manure, he adds, ' often causes a crop of strawberries to be lost, by forcing the growth of leaves. Liquid may be applied just when the plants are forming their flower buds,and the strength of the manure is spent in producing fruit, not leaves. When the plants were bearing, it could be seew to a plant how far the irrigation had extended".

Indeed, it should be ovious. that since liquid manure owes its value to its being in the state in which plants can immediately consume it, to administer it when they are incapable of consuming it, that is to say, when they are not growing, is most absurd. This is, however, a point concerning which more requires to be said than we can to day find room for. Lindfey - Gard. Chronicle.

Liquid Manure #1

Any manurial matters can be, to a more or less extent, dissolved in water for the production of liquid manure, and the strength of the material used must regulate the quantity of water applied, and the nature of the plants to be fed with it. The following proportions, taken from the London Gardener's Magazine, are considered useful mixtures: One part by weight of fresh cow-dung to six parts by weight of water; stir, and leave it some hours to settle; use only the clear liquid. The drainage from the stable and cowhouse is a most valuable basis for liquid.

Liquid Manure #1

"We believe there is no system of enriching the land for small gardens, with a view to perfection of crops, so truly economical and so easily available as that of using liquid manure. We occasionally hear of a gardener, or an amateur grower of some special plant or crop, that has practiced enriching with liquids, but it is only occasionally; yet the result of every record is in its favor, and a searching inquiry into any extra production of fruit, flower, or plant almost invariably gives watering with liquid manure as the cause. There is in almost every family waste of liquids, which usually go into the sewer or drain, or possibly upon the road, where they are no avail, but if saved, by being conducted to a tank, would enrich the entire garden spot of vegetables, small fruits, furnish stimulus to the rose and other flower borders, and keep the grass plot green and fresh even in the hottest and driest weather of midsummer. The use of a little plaster (gypsum) occasionally, thrown in and around the tank, would always keep it sweet and clean.

By the use and practice of liquid manuring no delay need ever occur in planting-time because of the manure not being on hand, or not being in a sufficiently rotted condition ; but planting could proceed, and the application of manure be made at leisure.