Show cause of black heart the usual causes of blach black feirt are piling potatoes too deep or putting them in bins where there has hag been no circulation of air and maintain ng too high a temperature in the storage place where potatoes are kept at temperatures below 45 degrees fah they can be piled as deep as 6 feet without danger of injury but where the temperature is I 1 kely to be 50 degrees or above as is the case in some cellars it is not safe to pile them more than 3 feet deep if they are to be kept longer than three or four |