I came out, Ma’am, prepared to submit to everything—to be put upon in every way—but there are some things, Ma’am, one can’t submit to. There is caps, Ma’am, that suits one face and some that suits another’s, and if I’d known, Ma’am, about the caps, great as was my desire to come out to nurse at Scutari, I wouldn’t have come, Ma’am.
I found this from Florence Nightingale's letter.
If "caps" mean a kind of a hat here, in what usage does caps used with singular be a verb, "is"