Which microscope would you use if you wanted to study the surface of an object?

If you want to study the surface of an object, the microscope you will use is A SCANNING ELECTRON MICROSCOPE.
Scanning electron microscope scan a focused  electron beam over a surface to create an image. The electrons in the beam interact with the sample and produce various signals that can be used to obtain information about the surface topography and composition of the object.

the most likely explanation for this is that his wounds have started to scab over and that stops the bleeding.