Principles of Shaving - 1825
This one from 1825 from the book "The Art of Preserving the Hair". Interesting in any event but the part I found that was really interesting and pertinent starts on page 241 and is the section entitled "X.-On Beards, Mustachios an Whiskers". Page 247 begins a subsection entitled "Principles of Shaving". I'm sure there's many more interesting chapters.
As with the others, it's readable online, an you can download for reading later. The link is at:
The art of preserving the hair, on ... - Google Books
and should start you right at tpage 250 where you can navigate around.