"herring-broth" as an ethnic slur?

[George Thompson]

John Middleton was indicted for an assault on Mary Gibson.  The prosecutrix is a married woman of reputation, a native of Ireland.  On Sunday the 2d. inst. the prisoner came into her apartment, where she and her husband were at breakfast, and enquired if she could not give him some herring-broth.  Conceiving this to be a gross national as well as personal insult, the prosecutrix threw the contents of the slop-bowl in his face, and he departed to all appearance perfectly satisfied.  [Later, he meets her in the street, as she is leaving church, and kicks her,] telling her at the same time that he was giving her a little herring-broth.  [He gets 6 months.]  New-York Commercial Advertiser, August 18, 1807, p. 2, col. 4 - p. 3, col. 1

Is this a traditional reflection on the poverty of Ireland?  I believe that herrings have in English anyway a reputation as a poor sort of food.  No doubt "herring-broth" would be a thin sort of broth.  I've never encountered the expression, though Ms. Gibson seems to have understood it readily.

GAT

George A. Thompson
Author of A Documentary History of "The African
Theatre", Northwestern Univ. Pr., 1998.