Sentence:  A notable instance of this character was the issue by the city in 1873 of the "<WSD>Brownbacks</WSD>,” so called, as circulating notes, which were not regarded as a violation of this provision of the charter, and which were retired by the proceeds of a special  tax levied and collected for that purpose after the present charter came in force. 
Meaning of the word marked with <WSD> tags:  A note of scrip printed on brown paper, such as that issued by the city of St. Louis during a financial crisis.