No. No. It is from Gail. It is the same inscription that Gale had in his cook book. He even spelled honor like honour with the u.
I hope they have a flashback about the book.
you're right about this...I remember now Gale giving Walt a book as a present to make peace between them
This is ambiguous...
1) You never actually see Gale give the book to Walter...In the episode "Sunset"...the episode when Gale and Walter first meet, Gale quotes the poem. A few scene later, Walter is in his apartment looking over the book "Leaves of Grass" and there is a close up of the inscription.
2) Gretchen in the 1980's was Walter's lab assistant before she married Elliot. Walter and Gretchen seemed to have had a close friendship going that came close to a romance. Gretchen, however, chose Elliot over Walter. The inscription on the poetry book looks very much like a "consolation gift" to a rejected lover. Walter in the scenes with the book seems to venerate it as an emotional keepsake.
3) There is some argument over the similar handwriting styles of both the inscription and the lab book. Both Gretchen and Gale have science backgrounds. Some universities have classes for engineering/science students to teach that style of block lettering. At the University of Houston the class was called "Engineering Graphics 100". These classes seek to standardize the appearance of handwritten documents.
4) It is very much more in keeping with the "Greek Tragedy" style of the production to have something that deceives Hank into thinking that both documents were written by Gale...but actually are unrelated, but still serves the purpose of putting him on the right track.
This is why I think the poetry book is from Gretchen...