Manner of Operation 89 
taken not to loosen or separate the bark from the wood at 
the margin of the wound, or to crush the cambium in this 
region. 
All wounds must be smoothed and then heavily dressed 
with an antiseptic, impenetrable cover, in order to keep out 
water, and with it, bacteria 
and fungi. Common lead 
paint answers this purpose 
best, being antiseptic as well 
as lastingly impenetrable to 
water. By making it as nearly 
as possible the same color as the bark the unsightliness is 
reduced. Coal tar is also recommended, but aside from 
its unsightly color it sometimes damages the cambium at 
the edges, and is not as easily handled as lead paint. 
Be sure to make the coating thorough, possibly applying 
two or three coats. This coating or dressing does not 
influence the healing process in any way, but is merely 
a mechanical device to keep out water and fungus spores. 
Therefore, every cranny should be filled, especially the 
lower edge, which collects water more easily. If cracks 
appear, the coating must be renewed so as to fill them and 
keep out the surface waters. 
With the observation of these few simple rules, any intel- 
ligent man can do the ordinary pruning without doing dam- 
age. 
As to the time of pruning, there are advantages and dis~ 
advantages in every season, although the operation may be 
performed at any time with safety, provided it is properly 
executed. During the early growing season, when the bark 
peels easily, there is greater danger of injuring the tree 
mechanically by bruising the bark; so it is better to defer 
the pruning until fall, winter, or very early spring. In 
Fic 19 — Topping shears 
