I don't think all trees will bear slitting the bark any more than all will bear " oil." It seems to me that your grounds must bear remarkably sturdy specimens that can bear any thing; as we see children that do grow up into six feet manhood, in spite of paregoric and soothing syrup in babyhood, and tobacco in their callow youth. I do know that we lost a great quantity of cherry trees by slitting the bark thereof, under the eye of a noted horticulturist and warm advocate of that theory, about twenty years ago. We had fruit enough, besides what the birds ate, to use and to sell, before that terrible experiment was tried; and now we have none to speak of. The few trees that survived the ordeal have never borne enough for the birds; in fact they are mere cumberers of the soil only. Being valuable sorts, we cannot bear to dig them up.