Sentence:  But there has none employed my Thoughts of late ſo much, as a very nice inquiſition, or inſpection, into the frequent differences we meet with Human <WSD>Ordure</WSD>. The World may ſay, perhaps, I had very little to do, and that ſo ſolemn and ſerious a Preface, ill became ſo foul a Subject; but let what will be ſaid, I can't help communicating my Sentiments, but will endeavour to wrap 'em up in as cleanly a manner, as the dirtineſs of the Theme will admit. 
Meaning of the word marked with <WSD> tags:  Dung, excrement.