Returning from the Lily House, we pass down on another side of the Cactus House, the rafters of which are clothed with Bignonia venusta, adorned with festoons of flowers, Bignonia picta, Passiflora elata, etc., in luxuriant health.

No. 6. Orange-House

38 feet in length and 14 in width. This house, besides containing a collection of trees such as its name implies, and immense specimens of American Aloe, or Century Plant, India Rubber, Camphor Tree, Finger Lemon, Forbidden Fruit,different kinds of teas and other plants merely requiring protection from frost in the winter season, contains also the main reservoir from whence all the houses are supplied with water. It is lined with lead, and contains about 2,000 gallons. The water is forced up by two of Douglas' largest (No. 6) rams, from springs rising on the farm, 1,500 feet distant. One of these supplies the Mansion-House in the summer season, the excess flowing over from a higher reservoir being led into this. Adjoining this house, and running parallel with it, is.

No. 7. The Orchid-House

$8 feet in length and 10 feet in width. This house is heated by hot water, partly with four-inch pipes, and partly on the " tank system," and by the same boiler used for the last house. A brick pit is constructed inside, which, near its top, supports a divided iron tank, open above, and through which water flows when heated, and returns again to the boiler. This is covered over by tarred oak slats, sustaining a bed of gravel upon which plants requiring moist bottom heat are placed. From apertures in the side of the brick pits, steam is made to permeate the house, when, and as desired. There is probably no house on the premises more interesting than this one. A house properly adapted to the growth of the air plants of the tropics, hanging, apparently from threads, to the branches of trees, or seemingly springing from dried blocks, trunks; and old roots, as described in the narratives of tropical travellers, is one of the sights often heard of, but seldom seen in this country as yet. In this house may generally be seen some of these wonderful productions of Flora in flower - now resembling some bird, now some moth, and at other times butterflies, or other insects.

The celebrated Espiritn santo, or "Dove Plant" of the Isthmus, seems to grow and flower here as perfectly, if not better, than in its native localities.

No. 8. Vinary

31 feet in length by 12 feet in width, on the "lean-to" principle. This house has an ordinary furnace and brick flue, by which grapes may be forwarded a little earlier, when desired, than in those in the "cold vinery".

No. 9. Vinery

Same dimensions as the last, and heated in the same manner.

No. 10. Nectarine-House

62 feet long and 12 feet wide, on the same principle, and in range with the two last. The nectarines are trained to trellises against the wall, on the highest side, Black Hamburg Grapes principally ocoupying the rafters in front. There is no artificial heat in this house, it being employed aa a cold vinery as well as a Nectarine-House.

No. 11. Vinery

Called the "White House," because there are no others than White Grapes, " Muscat of Alexandria," growing in it. It is 31 feet by 16.

No. 12. Vinery

Comprising a miscellaneous collection of grapes. Dimensions same as the preceding. Both these houses are heated by hot water from one large boiler, with the circulation capable of being so regulated to any required temperature without interfering with that of the other. The vines on the rafters are taken down during the winter, and boxed up, so that the warmth inside the house has no effect on them, while the process of forcing Peaches, Nectarines, Apricots, Figs, Strawberries, Grapes, etc, in tubs and pots, is being carried on. Strawberries are ripened in these houses in February, Figs in March, Grapes in April, Apricots, Peaches, etc, in May. Both houses are neatly paved with pressed brick, as most convenient and agreeable, where so many trees cover the floor, and requiring the frequent attendance of the gardener.

No. 13. Forcing-House

50 feet by 10. Used for forcing vegetables and propagating certain kinds of plants. It is heated by hot water. It is divided into two compartments, in the warmest of which Cucumbers and Tomatoes may be had nearly all through the winter season; and, in the other, Asparagus, Cauliflowers, Potatoes, etc, very early. . A small tank is placed in the house, which possesses considerable interest as being the birth-place of the renowned Victoria in this country. Seedlings of this plant, and other aquatics, are still flourishing in it, the machinery for warming which is perfect, as it is in all the houses thus heated.

No. 14. Camellia House

62 feet in length by 15 feet in width. It is filled exclusively with Camellias, numbering several hundred specimens, many of which are of large size. This house is heated by hot water.

The waste water from all the houses passes into a basin, in the kitchen garden, where many of the Lily tribe are growing, including the " Lotus," which stood there without protection one winter, and flowered the succeeding summer and fall profusely. It also abounds in gold and silver fish. In addition to the enumerated structures, others belonging to the horticultural grounds are worthy of note, as the Tool House, where the implements are arranged with the regularity of an armory, the Carpenter's Shop, the Compost House, Mushroom House, etc.

The premises may be viewed at any time after the 1st of May, between the hours of 10 and 12, and 3 and 5, upon an order of the Auctioneers, M. Thomas & Sons, Philadelphia, to whom, for further particulars, inquiries must be addressed.

Dear Horticulturist: If I might be permitted to intrude for a moment among the young people who partake of the savory scraps at the " Editor's Table," I would remind those of them who have a taste for the beautiful in nature, that the season is at hand when her vegetable beauties are most profusely displayed; and would say to all who desire to have a national acquaintance with those charming objects, that a work has been recently prepared by Professor A. Gray, of Harvard University, entitled First Lessons in Botany, which is most admirably adapted to the wants of beginners in the "amiable science." In my opinion, i more thoroughly and successfully blends the useful with the agreeable than any other elementary treatise extant. Were Horace now living, and duly posted on the subject, I am sure he would say of it: "Omne tulit punctum".

The illustrations are as ample, and so complete, so strictly scientific, yet so plain and familiar, that the way-faring boy, though a booby, cannot fail to comprehend them. I would therefore advise all the youthful listeners around your editorial table who would provide a store of pleasant knowledge for future enjoyment, to avail themselves forthwith of the aid thus furnished by an accomplished teacher. Yours, truly, Senex.

April, 1857.

Coboubg, C. W., Feb. 18,1857.

Mr. Editor: You say the Cloth of Gold is the finest Climbing Rose! If it is anything like the old Cloth of Gold, we would like to know where it is to be had, and how it is propagated? By layers! by cuttings? or by budding? B. Loser Ans. By all.

Sir: A correspondent in the February number wishes to know a remedy to prevent mice from girdling trees. The best thing I ever found, is to put white birch bark, in June or July, from trees four or five inches through; it will curl up very readily, and may be placed around the tree in the fall, and earthed up a little. It may also be laid in the spring, for another season, it being very durable. This will prevent the mice from working under. Earthing up twelve or fifteen inches is a very good plan in the fall, and remove it in the spring. Mice often come out from the rubbish about the fences, such as brush or stone heaps, or from woodlands. Grass should be grazed off about the fences in the fall; it is a great harbor for mice. Yours, B. Loser, Nurseryman, Cobourg, C. W.