It is known that rotten potatoes, like rotten turnips, when left in heaps in contact with sound ones, will cause the latter to rot. Aware of this fact, farmers have, this last year, caused the potatoes in the heaps, as soon as the lifting of the crop was over, to be individually examined, and placed the sound ones in narrow, low pits, mixed with some desiccating substance, and covered with straw and earth. When the pits were opened for examination, the rot was found to have spread very much, in consequence of the dampness and heat which was so diffused throughout the pits. This is an effect that might have been anticipated. Had the precaution been used of taking up the crop in small quantities at a time, or of spreading the potatoes on the ground when the weather was fair, or in sheds when wet--and of allowing them to be exposed to the air until they had became tolerably firm and dry; and had the sound potatoes been then selected by hand, piled together, and afterwards put into smaller pits, it is probable that a much less proportion of any crop that was taken up would have been lost. Such a plan, no doubt, would have caused a protracted potato harvest, but the loss of time at that period, in performing the necessary work of selection, is a small consideration compared with an extensive injury to the crop. It is no doubt desirable to have the potato land ploughed for wheat as soon as possible after the potatoes have been removed; but there is no more urgency in ploughing potato than in ploughing turnip land for wheat; and, at any rate, it is better to delay the ploughing of the potato land for a few days, than run the risk of losing a whole crop of so excellent an esculent. I may here mention an experiment in regard to the potato, which shows that a larger crop has been received by planting the sets in autumn than in spring. Those who have tried this system on a large scale say, that the increase is in the ratio of 111 to 80 bolls per acre. If this is near the truth, it would indicate, that the sets may safely be entrusted to lie in the ground all winter upon the dung; and could we be assured of their safety there in all cases, the potatoes of this year, selected in the manner above described, might be used as seed this winter and preserved as such, in the ground, in a safer state than even in the small pits. Such an experiment may be tried this winter, in dry weather, without much risk of losing the future crop; for if, on examination in spring, it should be found that all the sets have rotted in the drills, there would be plenty of time to replant the crop, in its proper season, with the sets that had survived till that time, by the means of preservation used.