It is illegal to throw pickle juice or any other bodily or foul liquid onto a passing trolley.

The Law Explained

Public transit in the early 1900s was messy enough without angry locals hurling rotting garbage or brine at the streetcars. This specific phrasing was drafted to protect both the transit operators and innocent passengers from unsavory liquid assaults. It seems that at some point, throwing pickle juice was a common enough prank to warrant state intervention. Next time you finish a jar of pickles, just pour the juice down the sink.