In books from the 19th century and the first half of the 20th century, I realised, that sometimes names are highlighted by increasing the spacing inside these words.
Here an Example from G. Frege's "Begriffsschrift"

where the name "Leibniz" is highlighted in this particular way. Is there a name for this style of typesetting? How can it be achieved in LaTeX?
I am interested in a solution for all flavours of LaTeX but a solution which is compatible with XeTeX and fontspec would be the preferred one.