Slang is one form of popular poetry. It will maintain its existence, in ever-fleeting shapes, so long as the mind of the masses has a poetic side, and will particularly flourish wherever circumstances favor the combination, in the ideas of the masses, of the grotesque and the novel with the imaginative. In this country, the West--and California, the farthest border of the West--is the hotbed of slang. A Western writer "spreads himself" at the expense of a rival who "welters" in "gush" or "slops over" too profusely. His darling aim is to get his own "head level" and to send his opponent off "on his ear." Of some of the phrases of this kind the origin is difficult to trace, and generally not worth tracing. Others are markedly metaphorical fittings of words with new meanings, and often highly expressive meanings. They are efforts of fancy not conveyed in metre, nor even in prose, but condensed into a single word or phrase. They thus become portable enough to run like lightning from tongue to tongue and pen to pen over a continent. But, like other electric flashes, they are not usually of long duration. If quickly started, they are as quickly forgotten. Each generation or decade or year manufactures its own supply of slang words, and seldom bequeaths any of them as a permanent inheritance. Delineators of rude or low life, like the litterateurs of the Pacific coast school, Dickens and Thackeray, embed in their writings the slang of their day; but it stays there, recommended though it may be by the brilliancy of its setting, and rarely passes into currency outside of their pages. Its flavor is usually too local and fugitive for that. As slang blends in one direction with genuine poetry, in another it sinks into the base jargon invented by evil-doers for the disguise of their intercourse and concealment of their purposes. Of the latter description are the dialects of the prize-ring and the fraternity of thieves. These are rich and copious, and often ingenious, like the other devices of their originators. How far the gypsy language may be included with them it is impossible to say; but it has been largely borrowed from by them, thanks either to community of objects, and consequent sympathy of feelings, or to its obscurity and shapelessness, and the utter ignorance of it among the intelligent and plunderable classes.