Sentence:  True, there are by the direction of the Law-giver, certain good and subs[tantial] Steps, placed even through the very midst of this "Slough"; but at such a time as this place doth much spue out [its filth] as it doth against change of weather, these steps are hardly seen; or if they be, Men through the diziness of their heads, step besides; and then they are <WSD>bemired</WSD> to purpose, notwithstanding the steps be there ... 
Meaning of the word marked with <WSD> tags:  To immerse or trap in mire.