" The battle is to decide whether you shall become a New Yorker or turn the rankest outlander and Philistine. You must be one or the other. You cannot remain neutral. You must be for or against - lover or enemy - bosom friend or outcast. And, oh, the city is a general in the ring. Not only by blows does it seek to subdue you. It woos you to its heart with the subtlety of a siren. It is a combination of Delilah, green Chartreuse, Beethoven, chloral and John L. in his best days. "

In O.Henry's day, chloral hydrate was often used as "knockout drops" to render incautious imbibers hors de
combat so that their pockets could be picked with impunity.
However a lot of alcohol plus chloral hydrate was a very
dangerous combination. Sometimes called a "Mickey Finn". I don't know the origin of that, and it may not be known.