A. J. Downing, Esq: May I trespass on your kindness by soliciting answers to the following queries: 1st. What is the best way of composting the leaves of the forest for manure? [By treating them with the lime and salt mixture described in Horticultural Vol. iv. p. 202.]

2d. Will unreached ashes or lime most readily promote the decomposition of leaves? [Either - but the latter will act most speedily.]

3d. Which in "your opinion" are the four best pears for market cultivation, (2 of them on quince and 2 on pear roots,) out of all the old and new varieties? I mean four most suited for this eastern climate and this naturally poor gravelly soil - four out of the vast collection - of a thrifty and vigorous growth. I know and appreciate the qualities of the Bartlett and Louise Bonne de Jersey, but would not a cultivator be at his wit's end to keep up the prices and sell 300 bushels of either the above named varieties, provided these sorts continue to be cultivated by "every body?" [No fear of an overstock of fine pears - no one will see it in our day. Your question is difficult. We should say Bartlett, Louise Bonne de Jersey, Vicar of Winkfield, and (if it answers on your soil) Black pear of Worcester.]

4th. Which is the best Raspberry for market cultivation, taking into consideration tenderness, firmness, and productiveness? [The true Red Antwerp.]

5th. How near may be planted the different varieties of squashes and melons without fear of mixing. For instance I have a two acre field, one-half of which I should like to devote to squashes next summer, and the other half to melons. Would the quality of each be deteriorated by so doing? [Will mix if nearer than 100 feet.]

6th. If the flavor of melons should become injured (a little squashy) the first year, would the 2d crop, planted with the seeds of the first, be 1iable to a further deterioration? [Of course, but so far as we have observed the fruit is not affected the first year, only the seed. The second year the mixture becomes apparent in the fruit.]

7th. Which is the best water-melon and the best winter squash? [The Spanish water melon and the Autumnal Marrow squash, are two very superior sorts.]

8th. Can plum trees be grafted in the spring with success, instead of the usual way of budding? [Yes, very easily, if by whip-grafting - but cleft-grafting requires more skill in the plum than in other fruit trees.]

9th. Does it injure apple pomace to be exposed to frosts, before planting in the spring? [How "in the spring?" The seeds should be freed from pomace as soon as possible in the fall.]

10th. Is it necessary that pits and seeds of fruit be buried in the ground to suffer the action of the frost, if planting be delayed till spring? [The action of the frost is not needed. What is needed, is that the seeds be kept moist in damp earth during the winter, and if the earth is not froze at all, so much the better. If the seeds have become dry it will be necessary to soak them for half an hour in hot water - not quite boiling - before planting.]

11th. Can you give me any information in regard to the invaluable mineral substance re-cently discovered in New-Jersey. It will work miracles,mixed with ashes,on our unfertile land. You may have had means of knowing at what expense it might be obtained in Newark or New-York? [Know nothing of it, and will be glad to learn what it is.]

With sorrow at troubling you with so many queries, mixed with joy at being allowed to seek all this information at the fountain head, I remain your friend, A. J. R. New-Bedford, Mass., Feb. 6,1851.