Wilfred Funk (1882–1965)

30 Days...is pretty interesting. Some of the vocabulary has changed definitions over the years (for instance, chauvinistic no longer means obsessive love of your country. And I don't think schizophrenia has ever meant multiple personality disorder (now dissociative identity disorder); that's one of those Hollywood things). But it's pretty engaging for a book on vocabulary.

good

“Every word was once a poem,” is the first sentence of the book. Funk supports this thesis beautifully.

Some of the words this book teaches have had changes in meaning since it was first published, some others are just dated in general. Regardless, I would say that at least 95% of the material is very useful. I used this book in high school and many of the words I learned from it are still part of my daily vocabulary.