An example of a word which was at first used as slang not many years ago, and is now, if not the most elegant English, at least a quite respectable word for newspaper use, is _maffick_. This word means to make a noisy show of joy over news of a victory. It dates from the relief of Mafeking by the British in 1900. When news of its relief came people at home seemed to go mad with joy. They rushed into the streets shouting and cheering, and there was a great deal of noise and confusion. It was noticed over and over again that there was no "mafficking" over successes in the Great War. People felt it too seriously to make a great noise about it.
A slang word which has become common in England during the Great War is _sträfe_. This is the German word for "punish," and became quite familiar to English people through the hope and prayer to which the Germans were always giving expression that God would "sträfe" England. The soldiers caught hold of the word, and it was very much used in a humorous way both at home and abroad. But it is not at all likely to become a regular English word, and perhaps will not even remain as slang after the war.
Besides the fact that slang often becomes good English, we have to notice that good English often becomes slang. One of the most common forms of slang is to use words, and especially adjectives, which mean a great deal in themselves to describe quite small and ordinary things. To speak of a "splendid" or "magnificent" breakfast, for instance, is to use words out of proportion to the subject, though of course they are excellent words in themselves; but this is a mild form of slang.
There are many people now who fill their conversation with superlatives, although they speak of the most commonplace things. A theatrical performance will be "perfectly heavenly," an actress "perfectly divine." Apart from the fact that nothing and no one merely human can be "divine," divinity itself is perfection, and it is therefore not only unnecessary but actually incorrect to add "perfectly." A scene or landscape may very properly be described as "enchanting," but when the adjective is applied too easily it is a case of good English becoming slang.
Then, besides the use of superlative adjectives to describe things which do not deserve such descriptions, there is a crowd of rarer words used in a special sense to praise things.