For ruta baga turnips, there should be 600 lbs. sown to the acre; plow twice and harrow well after sown. After you have hoed them out, give them a light top dressing of more guano. I have raised at the rate of 700 bushels, managed in that way, to the acre. We have had one of the most extreme drouths the present season I ever remember. Crops on which guano was used, have suffered less, and are now yielding better than where stable manure has been used. This is quite different from the opinion that some have formed, as to guano requiring a wet season. To prepare guano for use, it should first be sifted, to separate the lumps, so that they may be pulverized, then dampen by sprinkling with water, and mixed through with a shovel. This should be done a few days before you wish to use it, so as to allow the dampness to strike through uniform. (3) I have not had any experience with compost, or using it on garden vegetables, or plants, except I know it should be used in homeopathic doses, or it will destroy more than it will produce. As to the soil, guano answers well anywhere on Long Island, although some parts of the Island has a very different soil from others, with one exception; that is, it is all hungry for manure. I therefore do not know the kind of soil it is most applicable to, since it seems to suit all kinds. SETH CHAPMAN." NOTE 1. This practice of hauling manure to the field in the fall, is the worst of all the foolish old fashions of farmers. To preserve the virtue, of manure, it requires housing about as much as hay. In fact, it is doubtful which would lose virtue fastest, a pile of hay or a pile of manure, exposed to the storms of winter. It is no wonder that it becomes necessary to mix guano with it, to replace that which has evaporated during its long exposure to sun and storm. NOTE 2. This increase of straw, is seldom taken into account in speaking of the advantage of an application of guano; yet, as Mr. Chapman says, it is worth enough in the vicinity of a market, to pay the whole expense. It is also valuable in the interior for forage and manure. NOTE 3. This is an error. Guano should not be damped unless with water saturated with salt, copperas, or a liberal sprinkle of plaster over the pile. LETTER FROM SETH RAVNOR, OF MANORVILLE TO MR. CHAPMAN.--Successful experiments on grass, oats, corn, wheat and rye. "_Manorville, Sept._ 8, 1852.