So ima just say a few things- number one: ignore my rating its required here. Number two: the arguments over it are really pointless to be honest- simply for the fact that it is a racist view- but a good historical view into the mindset of many people back then.
Its not something really meant to be "read" in the sense of a regular book, more so to be studied or evaluated if need be- the only instance that i'd really imagine it coming up though would be for school research or something like that.
So yeah-
Racist? Yes.
Historical source? Yes.
Keep it to study or burn every copy of it? Do what you want with it I guess.