S. CHAPMAN, ESQ.--Dear Sir;--I have received your circular proposing to gather information from practical farmers of the results from the use of guano, and to have the same published for general circulation. Conceiving the object to be a very laudable one, I will give the result of a few experiments tried with Peruvian guano by myself, and others which have come under my observation; but in doing so I think it would be of great utility to state what kind of soil the guano was applied to. Not being a professor of geology, I can only use such terms as are familiar with farmers generally. The soils in this vicinity are heavy loam, sandy loam, sandy, and occasionally some heavy clayey soils. First, as to the nature of guano. It is generally considered to be more of a stimulant than an enricher of the soil, if applied in its natural state, and much more durable to be plowed in than to be harrowed in; and as far as I have tried it, I have not found it to be injurious to soils--or as some call it, 'kill the soil.' In the year '49 I applied on the first of April, 176 lbs. per acre on sandy loam grass ground--yield, about half a ton more than the acre adjoining. Same year applied about 150 lbs. to the acre, on four acres of oats, same kind of soil, and the estimated increase was 20 bushels to the acre. In 1850 plowed under 400 pounds per acre, for corn, estimated increase, 15 bushels of ears. The season was rather unfavorable for corn. In '51 composted six bushels charcoal dust to 100 lbs. guano, and plowed under for wheat, at the rate of 500 lbs. of guano so composted, to the acre, and top dressed with 100 bushels of leached ashes--yield, 20 bushels. One of my neighbors applied for three years in succession, 100 lbs. harrowed in with rye, on two acres light sand--yield, 14 bushels to the acre; 10 bushels more than the acre adjoining. On the fourth year he sowed the same ground without guano--- yield, 4 bushels to the acre. We see by this, that the crop used the whole strength of the guano. Another neighbor applied one ton to two acres, heavy loam; plowed under and sowed with turnips (common Russian)--yield, 1,300 bushels--estimated increase from the guano, 600 bushels. People in this section of the Island are agreed in this--plow under guano for durability, and harrow in for present benefit, or present crop. For wheat, 500 lbs. plowed in is considered a full dressing per acre. The same for corn. For oats, 200 lbs. harrowed in. For buckwheat, 100 lbs., and 200 for barley. One tablespoonful applied in a hill, for corn, is quite enough, and that requires to be put some six inches from the seed; otherwise it will kill it. Some have lost acres by putting their corn on that little quantity; the only safe