Swift says that he has digressed in lines 159-170. explain how this digression actually serves his purpose of exposing english injustice.

Swift at that point raises a potential protest to his proposition: that it will drain Ireland's populace. Quick reacts by saying this is the point. He says that this proposition will not the slightest bit hamper England, as the newborn children won't most likely be traded, as their tissue isn't actually saved for later utilization. He isn't happy to engage some other contentions for taking care of the issue, similar to ethicalness and thrift.  

Swift finishes up by saying first that he would respect some other proposals anybody may have on this inquiry, at that point guaranteeing the peruser that he has no close to home monetary stake in this thought since he has no youngsters and consequently couldn't benefit by pitching them to be eaten.

can you copy and paste what selections you read? the answer is based off of that.

it was surely an odd creature that one made up by reading the historians first and the poets afterwards a worm winged like an eagle; the spirit of life and elegance and charm,   in a kitchen chopping up suet. but these creatures, monst'r however entertaining to the imagination, hast no existence in fact. what one might doth to bringeth h'r to life wast to bethink poetically and prosaically at one and the same moment,   thus keeping in toucheth with fact—that the lady is mrs martin, ag'd thirty-six, did dress in blue, wearing a black coxcomb and brown shoeth; but not losing sight of fiction eith'r—that the lady is a vessel in which all s'rts of spirits and f'rces art coursing and flashing p'rpetually. the moment, howev'r, yond one tries this method with the elizabethan mistress, one brancheth of illumination fails; one is did hold up by the scarcity of facts.   one knoweth nothing detailed, nothing p'rfectly true and substantial about h'r.   hist'ry scarcely mentions h'r.   and i did turn to professeth'r trevelyan again to seeth what hist'ry meanteth to that gent.   i hath found by looking at his chapt'r headings yond t meanteth.