To vent my spleen against

Jane Austen, The History of England. Presaging in her youth, many of the academics and pundits of later years.

I suppose you know all about the Wars between him & the Duke of York who was of the right side; if you do not, you had better read some other History, for I shall not be very diffuse in this, meaning by it only to vent my Spleen against, & shew my Hatred to all those people whose parties or principles do not suit with mine, & not to give information.