This made a breach between us; and, when he returned again to London, he let me know he thought I had cancell’d all the obligations he had been under to me.
One of our common acquaintance jocosely remark’d, that, knowing it to be the custom of the saints, when they received any favour, to shift the burden of the obligation from off their own shoulders, and place it in heaven, I had contriv’d to fix it on earth.
I told them I could not propose a separation while any prospect remain’d of the Merediths’ fulfilling their part of our agreement, because I thought myself under great obligations to them for what they had done, and would do if they could; but, if they finally fail’d in their performance, and our partnership must be dissolv’d, I should then think myself at liberty to accept the assistance of my friends.
…writings contain’d a description of experiments which any one might repeat and verify, and if not to be verifi’d, could not be defended; or of observations offer’d as conjectures, and not delivered dogmatically, therefore not laying me under any obligation to defend them; and reflecting that a dispute between two persons, writing in different languages, might be lengthened greatly by mistranslations, and thence misconceptions of one another’s meaning, much of one of the abbe’s letters…
There are no more uses of "obligation" in the book.