All cuts are to be made sufficiently close to the parent stem so that healing can readily start under normal conditions. All dead and diseased wood shall be removed. All limbs one inch in diameter or more must be precut to prevent splitting. All branches in danger of injuring the tree in falling shall be lowered by ropes. A crossed or rubbing branch shall be removed where practicable, but removal shall not leave large holes in the general outline of the tree. Crossed or rubbing branches may be cabled apart. All cuts, old or new, one inch in diameter or more, shall be painted with an approved tree wound dressing. On old wounds, care shall be taken to paint exposed wood only. Where there is a known danger of transmitting disease by tools, said tools shall be disinfected with alcohol before use on another tree. Improperly healed scars, where callous growth is not established, are to be traced and painted, unless the Street Superintendent designates other treatment. No topping or dehorning of trees shall be permitted except by special written permission of the Street Superintendent. Trees becoming stag-headed may have the dead portions removed back to sound green wood, with a proper 45 degree cut only. Elm wood trimmed, pruned or removed shall not be used for any purpose, but shall be disposed of immediately by burning or burying.