Baudelaire (From More Rosettagrams Page) Clue:

CIPHERTEXT  letter D= plaintext H

English

yhi bfvi oi Hmxx
qHm Hhxxhe-mgmy, qHm pHvnqm mxkocv pvam,
qcmawxoil viy kmoxmy, qh kome Hmc qcvoqhc nzhfnm,
evn oq him xvnq wcolHq naoxm nHm qHhflHq qh pxvoa,
nfpH vn avym nemmq qHm ahcioil hs Hon khen?

V lcmvq nqhim avi chnm xoum v qhemc hi whvcy,
nqhhy vq qHm Hmxa viy pxmsq qHm sxhhy zchshfiy:
wfq qHm pvxa Hmch, xmvioil hi Hon nehcy
lvrmy wvpu, viy ehfxy ihq hssmc him xhhu chfiy.

French

yhi bfvi vfj mismcn
sconnhiiviq nhfn nhi ymfox, xv pHvnqm mq avolcm mxkocm,
zomn ym x'mzhfj zmcsoym mq tfo sfq nhi vaviq,
nmawxvoq xfo cmpxvamc fi nfzcmam nhfcocm
hf wcoxxvq xv yhfpmfc ym nhi zcmaomc nmcamiq.

Qhfq ychoq yvin nhi vcafcm, fi lcviy Hhaam ym zomccm
nm qmivoq v xv wvccm mq phfzvoq xm sxhq ihoc,
avon xm pvxam Hmchn, phfcwm nfc nv cvzomcm,
cmlvcyvoq xm noxxvlm mq lm yvolivoq comi khoc