clothed from the edge of the pot to the summit with a regular arrangement of blooming shoots. Occasional pinching off the points of the leaders or laterals will be necessary to effect the purpose, but with such attention any desired form is readily obtained. When required to bloom in winter or early in spring, it takes about five or six weeks from beginning to push till they are in bloom, and by regular introduction a constant succession from Christmas to July may be had. Some excellent articles on the Calceolaria are inserted in the volumes for 1843, 1844, and 1845, to which we respectfully refer our correspondent.]

ON HEATING A SMALL GREENHOUSE.-You will greatly oblige me by informing me, in the next Number of your instructive and excellent work, whether it is indispensably necessary that a small greenhouse which I am about to erect should be heated during the winter, in order to preserve the plants therein. It will be upon a very small scale, and I do not mean to attempt to grow any but such plants as I have been in the habit of having in my house. I am told, however, that unless I am prepared with some means of heating the greenhouse in the severe frosts of winter, I have no chance of preserving my plants. This will add a good deal to the expense, and I am unwilling to incur it unless I am well advised of its necessity. By doing so you will greatly oblige

A NORTH COUNTRY SUBSCRIBER.

[In our Magazine for February, 1840, a correspondent informs us of a very cheap and effectual plan he had adopted in heating a Greenhouse, which he recommended with the greatest assurance of success. It consists simply of a fire-brick stove, on the same principle as Dr. Arnott, with a cast-iron top and air-tight doors. He found it distribute the heat much more equally than an iron one. A stove of this description, 2 feet by 17 inches, and 3 feet high, is sufficient to heat a large greenhouse, requiring no chimney, a small pot tube being quite sufficient, and only consuming a peck of cinders per day. It requires a valve in the bottom door, by means of which the heat may be regulated to any temperature. We find Mr. Rivers, nurseryman, of Sawbridgeworth, has long used the iron Arnott's stove, but recently has erected the fire-brick ones, and even finds them succeed admirably for forcing houses for his Roses. To prevent dust arising from clearing away ashes, &c., the boy sprinkles them over first with water, so that no injury arises therefrom. Upon the top of the stove a pan is placed, the size of the square, a few inches deep, so that when it is necessary to have a moist atmosphere water is poured into it, and being heated thus becomes serviceable to vegetation. A stove of this kind would only cost about from 20s. to 30s., and would serve for a generation. Our correspondent would only require, as we understand, to keep out frost, and occasionally dry up damp, so that this kind of stove would answer most fully every purpose, and be a very trifling cost. Its erection in the greenhouse may be made ornamental, and should be placed near the front, so that the heat may be properly distributed.]

ROSES.-One of your correspondents inquires how the Crimson Hybrid China Rose "Fulgens" is made to flower? Simply by using the knife very sparingly in the pruning season. If you cut back the Hybrid Chinas, as you ought to do ordinary Roses, many, and especially Fulgens, will not flower the next season. I did not discover this for some time, and obtained an amazing growth of wood without any flowers; since I have shortened the shoots of the preceding summer about one-fourth part only of their length, I have found this rose bloom as freely as any. The best mode of training this rose and its brethren, Beauty of Billiard, Brennus, Legouvé, Triomphe d'Angers, &c., all splendid freegrowing roses, is to get them standard high, and place against them an iron stake; the feet made square and flat, and eighteen inches long; the stake branching off at the top, in the form of a cross, so as to support an iron ring, three feet in diameter, which should stand about two or three inches lower than the head of the stock. At the winter pruning, a sufficient number of the shoots must be brought down all round the circle, and tied with tar twine. These roses, thus treated, will present magnificent heads of flower the following summer.

ROSA.

LONDON HORTICULTURAL SOCIETY, April 21st.-A paper was read from Mr. Maher, relative to the prevailing disease in Potatoes, the principal features of which were as follows. A thunder-storm, accompanied by high winds, having occurred in July, 1845, washing away the soil from the tubers, Mr. Maher was of opinion that the disease was caused by the heated water passing down by the cavity formed by the wind-waving of the haulm, and that the malady might be prevented from further spread by storing the tubers when taken up in perfectly dry earth. Specimens illustrative of the good effects of this mode of storing were produced. These evidently showed that they had at one time been diseased; but that its further progress had been stayed by this method of storing. Mr. Maher was also of opinion that the remaining sound portion of the tuber might be safely used as sets for the next year's crop. In regard to other matters, Mr. Rae, gardener to J. J. Blandy, Esq., sent various Orchids, especially a fine specimen of the showy Cattleya Skinneri, Peristeria Humboldti with four pendulous spikes of dingy spotted blossoms, the sweet-smelling Lycaste aromatica, Oncidium pictum, Huntleya violacea with curious violetcoloured flowers, having something of the appearance of a bivalve shell, and a seedling Azalea. A Knightian medal was awarded.-From Mr. Alnutt, of Clapham, was a large specimen of Kennedya coccinea, for which a certificate was awarded.-Mr. Dobson, gardener to Mr. Beck, of Isleworth, received a certificate for a fine specimen of the larger and best variety of Oncidium ampliatum.-From the same collection were also Oncidium luridum and papilio, and the beautiful golden-veined Ceylon Anæctochilus setaceus, growing in company with the silver-veined American Physurus (—) under a bell-glass in an elegantly-formed Orchid basket. It was constructed of green slate, held together by brass clasps, and had altogether a very neat appearance, and was well calculated for being placed in a drawing-room.-Mr. Conway, of Brompton, sent a large coarse-looking Fuchsia, named Goliath, exhibiting a multiplication of the petals. Sports in this tribe being of frequent occurrence, it is not impossible that this, although probably the first double Fuchsia which has been exhibited, may be only the forerunner of a series of double-flowered varieties much more symmetrical than the subject in question. Mr. Redding, gardener to Sir J. D. Broughton, Bart., produced two magnificent cut specimens of a purple Rhododendron, named Alta-clerense Broughtonii, and Messrs. Veitch and Son, of Exeter, sent a Saccolabium, stated to be new, but which, if not S. micranthum very much resembled that species. Messrs. Fairbairn, of Clapham, received a certificate for a famous specimen of Erica vestita coccinea, every branch of which was surmounted by a ring of bright red blossoms.-Mr. Moore, gardener to R. Hanbury, Esq., sent Oncidium albo-violaceum, one of the most delicate of its class, for which a certificate was awarded; and a sweet-smelling Epidendrum, from Honduras, apparently E. varicosum, was exhibited by Mr. Low, of Clapton. Mr. Jackson, of Kingston, sent an Epacris-like plant, with small white flowers, from Swan River; and beautiful cut blooms of the Poppy Anemone came from Mr. Marshall, of Surbiton.—Mr. Glendinning, of the Chiswick Nursery, sent Begonia albo-coccinea, a pretty pink-flowered sort.From Mr. Anderson, gardener to the Marquis of Bath, was Lælia flava, a pretty yellow-flowered species, forming a striking contrast with the purpleblossomed kinds. From the same garden was also a sample of Ash-leaved Kidney Potatoes, which were said to have been produced from diseased sets. These were clean-skinned fine looking specimens, and apparently free from disease. One which was cut, however, for the purpose of trying them, very soon became discoloured in the centre when exposed, which is characteristic of the disease in an early stage.-From Mr. Plant, gardener to J. H. Schroder, Esq., were Vanda cristata, with bright brown streaked blossoms of no great beauty, and a good specimen of the showy Pimelea spectabilis.-Mr. Ayres, gardener to J. Cook, Esq., of Brooklands, sent an exceedingly well-managed Stephanotis floribunda, loaded with sweet-scented white blossoms down to the very pot, and a well-grown Ixora crocata, a pretty species, well deserving of more extensive cultivation than it has received. A Knightian medal was awarded for the Stephanotis.

LONDON HORTICULTURAL SOCIETY, May 5th.-A curious novelty came from the gardens of the Duke of Northumberland, at Syon, in the shape of Platycerium grande; one of those remarkable Ferns which grow on trunks of trees, deriving their sustenance from the atmosphere, and multiplying themselves by means of little patches of cinnamon-brown bodies, attached to the under sides of the leaves, looking something like diseased spots. A number of seedling plants raised from these bodies was produced, exhibiting a curious peculiarity of growth. The young plant increases in a horizontal direction for a time, then strengthening, throws up from the centre numerous large fronds, having the appearance of antlers; a form of growth observed by all the Platyceriums. A Knightian medal was awarded for this noble Fern, of which not more than two or three plants are as yet in England. To ensure success in raising seedlings, it was mentioned that the seed must be sown immediately when ripe. Messrs. Henderson, of Pine-apple-place, sent Hypocyrta strigillosa, a Solanum, with lilac blossoms, misnamed Salvia azurea, said to be suitable for bedding out, and Tremandra verticillata, a pretty little Heath-like Swan River plant, with beautiful violet flowers, having reddish-purple centres, the two colours_strikingly contrasting with each other; a Banksian medal was awarded it. From the nursery of Messrs. Rollisson, of Tooting, came Bifrenaria inodora, a rather pretty Orchid, having much resemblance to Maxillaria Harrisoniæ. Mr. Beck, of Isleworth, again sent a handsome green slate basket-an improvement on that produced at last meeting-containing two Orchids; Trichopilia tortilis, remarkable for its twisted petals, and Oncidium triquetrum, a rare East Indian species, with small pink spotted flowers. Sir T. D. Acland, Bart., sent blooms of a purple seedling Rhododendron from the open ground. From Messrs. Keeling and Hunt, of Monument-yard, were two Yams, weighing respectively 10 lbs. and 7 lbs., and samples of unprepared Ginger in a fit state for planting. Specimens in spirits received by Mr. Low, of Clapton, from his son, who is now in Borneo, were exhibited. One of the plants was stated to be a beautiful species of Hoya, with large white flowers with purple centres. All colour had, however, been extracted by the fluid in which they were preserved, and therefore little can be said about them in their present state. The other was an Epiphyte, and was mentioned to be an object of extreme beauty. It was found by Mr. Low, growing on old trunks of trees, producing long chains or racemes of inflorescence, 9 or 10 feet in length. Living plants of these were stated to be in England, and if we should succeed in flowering them in perfection, they cannot fail to be striking objects in cultivation. Of miscellaneous articles, Messrs. Edwards and Pell, of Southampton-street, Strand, sent two glass milk-pans.-From the Garden of the Society were Corethrostylis bracteata, a Swan River shrub, of which much was expected, but which has proved a partial failure, its pink flowers, although produced in abundance, wanting brilliancy of colour to render them sufficiently attractive; Eriostemum buxifolium, covered with delicate pink stars; three Indian Azaleas, a Cape Heath, Gloxinia caulescens, a Cineraria, a variety of Gesnera Douglasii, a rambling Oncidium from Guatemala, something in the way of O. Wentworthianum; a variety of Gongora maculata, Cyrtochilum hastatum, and a plant named Mina lobata, raised from seeds collected in Mexico by Mr. Hartweg, in his new expedition to California. From the appearance of the foliage of this pretty little plant, nobody could doubt its being a Convolvulus, which it certainly is, but the flowers are very unlike those of that tribe; instead of growing singly and spreading, they are contracted at the points, and produced in long one-sided racemes, of a bright orange in an early stage, but becoming pale yellow when full blown. From the same collection was also a bloom of the curious stove climber Aris tolochia gigas, whose large concave helmet-like blossoms have attracted the attention of everybody who has visited the gardens for some time back. Various specimens of wood, exhibiting curious expansions of different forms, looking as if they had been carved, were produced. These were, however, not carved, except by the hand of nature; they were the work of a parasite nearly related to our Misletoe, which, insinuating itself among the ends of branches, and increasing slowly, stops all growth in that direction. The tree, however, makes

an attempt to grow laterally, and in time almost encases the parasite in its woody embrace; at last the latter shrinks and tumbles out, leaving the beautiful anomalous expansions in question. These specimens were brought over from Guatemala by Mr. Skinner, and show what is going on in these respects in the woods of the tropics.

ON HEATING PLANT HOUSES, PIT FRAMES, &C.-Of late years considerable attention has been paid to improve the system of heating erections for horticultural and floricultural purposes. Much has been effected to advantage. Very recently a system termed the Polmaise has been often discussed, and in some instances has been put into operation in the erections of pits, &c. A great deal has been said in approval and disapproval of its merits; the following particulars relative to it by a nurseryman, Mr. Davis, of Liverpool, has been inserted in the "Gardener's Chronicle," which we extract, to afford our readers an opportunity of what the system is expected to realize.

Polmaise Heating.—A short time ago I was invited by a neighbour to inspect a new mode of heating horticultural buildings, which he termed the Polmaise system. He had erected a small pit running north and south, at one end of which, by way of experiment, he had built a chamber, in which he placed a very small iron stove. At the top of the chamber a hole was made into the pit, through which the hot air flowed at the bottom of the chamber. Immediately under the fire was the mouth of a drain, which ran to the other end of the pit, and through which the cold air was drawn. I went into the pit, and found there was a stream of hot air flowing from the chamber at a very high temperature, so hot that it had discoloured the paint on the wood directly above. A thermometer was placed at each end of the pit; the one most distant from the pit indicated 710, and the other 70°. The current passing along the top could not have been less than 90° in the centre of the pit, and nearer the chamber much higher. He proposed to modify the heat at the entrance from the chamber, and moisten the air by hanging a wet blanket over the hole. This part of his plan I objected to, for many reasons, and being about to erect a pit of simllar form, I resolved to get rid of the blanket, which I have, as well as of all the other objections given in your paper, and that too at a very light expense. I think I can convince you that I have set this grand principle free, and thus disencumbered it of the load of objections so unworthily heaped upon it, Every other mode of heating horticultural buildings will soon disappear; its cheapness, safety, and fitness will, I am sure, throw out of use the boiler, pipes, tank, and manure-bed. I will now attempt to describe my pit; it is 42 feet long by 8 feet wide inside, high roofed, having an east and west aspect, with a wall across the middle, dividing it equally. One half is used for propagating, and the other for greenhouse plants. At the end of the propagating compartment, I have built a chamber 30 inches wide by 36 inches long, and 24 inches high. In this is placed an iron stove, 17 inches long, 12 inches wide, and 12 inches in height; about 12 inches of the air-chamber is carried into the pit; the propagating part is covered with strong slates, giving a chamber of 21 feet long by 8 feet wide, and 30 inches deep. Into this the hot air flows through a hole at the top of the chamber, over which I have placed a piece of sheet iron, which is bent downwards to diffuse the heat and prevent its violence doing injury. From the bottom of the chamber a cold-air drain is carried the whole length of the pit, terminating with an eye at the end of the cold compartment. On this eye a slide is fixed to close the drain when required. In the large chamber there is another eye, which is left constantly open. I have built a small flue round the large chamber; the smoke is conducted through the hot-air chamber into the flue, and back into the chimney by iron pipes, which assist in heating this part as well as in giving an additional draught to the chimney, as will be readily perceived by the return-pipe passing through great heat. When I wish to warm the part intended for plants, I can do so in a few minutes, by drawing a slide which covers a hole that passes through the division wall into the large chamber. This

second chamber cannot be dispensed with, let you apply it to the greenhouse, stove, pit, or frame; the absence of a second chamber must prove fatal, or at least be very inconvenient; hence it is that we hear of scorched leaves, wet blankets, boilers, &c. With a second chamber none of these will be either heard of or required. The second chamber can be easily made in any house; in the Orchid house or stove it may be the stage, and if a greater top-heat is required, draw your slide, and immediately you have a stream of warm air charged with moisture to any extent required. This I can prove by experiments in my own pit. I have gone into the cold compartment when the thermometer has stood at 65° in the propagating part; having previously opened the door of my air-chamber about a quarter of an inch, and drawn the slide, the vapour gently flowing through has filled the place in a few minutes, at the same time gradually raising the thermometer until it has reached 60°. As respects the heat generally in the propagating compartment, I certainly never heard of any construction that would retain heat so long with so small a portion of fire. I got 10 cwt. of coke, which cost 3s. 4d. (?); this I have been burning these three weeks, and I expect it will last three weeks longer. I have kept up a high temperature constantly. I hava frequently left the pit at 65° at nine o'clock at night, and found it at 580 in the morning. On one occasion I left it at 60°, and found it in the morning at 59°. I have often left the fire for twelve or fourteen hours, and have found the heat very little diminished. Now for the expense of the apparatus. The whole of the iron work, including the plate and also the stone slab, cost 47. 6s.; and even this expense might be considerably reduced by purchasing a ready-made stove. The hot-air chamber and flues were built by one man in about a day and a-half. The flues I had built merely to prevent the escape of heat, and to save fuel. As for repairs, I do not expect any will be required for ten or fifteen years, except that the flues may want cleaning in three or four years.-Isaac Davies, Larkfield Nursery, Wavertree, near Liverpool.

DESTRUCTION OF RATS, MICE, &c.-Some gardeners are in the habit of employing arsenic for poisoning peas, beans, grain, meat, &c.. which they put in places frequented by rats and mice. This practice is exceedingly dangerous for other animals, and likewise for children. It is a much more simple and far less dangerous plan to rasp or crumble some bread, and mix it with equal quantities of powdered quick-lime and sugar, and lay small parcels of this mixture in the way of rats or mice. These, being very fond of sugar, eat the powder, and the liquids of the stomach coming in contact with the quick-lime, produce an effect analogous to that produced by water on this substance; it becomes quenched. The violent inflammation which results causes death; and this may be accelerated by placing a vessel full of water within the reach of the animals. -Revue Horticole.

GARDEN STRUCTURES FOR AMATEURS.-For a person who wishes to "try to cultivate many things," but who has "little money to spare for such purposes," a low brick pit, either heated by a hot-water pipe or not, would be most suitable; without a pipe he might keep many greenhouse plants in winter, and grow them in summer; with a pipe and proper attention he might grow most things as well as they could be grown in a greenhouse. This pit may be partially sunk if the ground is dry; and it may or may not be large enough to comprehend a narrow path at the back inside, under a roofing of boards or slate, which would greatly facilitate all operations of culture. The pipe should pass along the front and return behind; the glass roof should be at a very low angle; a stage inside, of any kind, or a bed of sand, gravel, or coal-ashes may be provided for the plants; the pipes should flow through a small tank, which would then serve as a reser voir of tepid water for the plants; the pathway of course may be lowered much more than the rest of the pit to get head-room. Such a pit may be from six to nine feet wide, and should be heated by a row of three-inch pipe passed round it, attached to the smallest sized boiler.- Gardeners' Journal.