Every profession or trade, every art, and every science has its technical vocabulary．Different occupations, however, differ widely in the character of their special vocabularies．In trades and handicrafts, and other vocations, like farming and fishery, that have occupied great numbers of men from re mote times, the technical vocabulary, is very old．It consists largely of native words, or of borrowed words that have worked themselves into the very fibre of our language．Hence, though highly technical in many particulars, these vocabularies are more familiar in sound, and more generally understood, than most other technicalities．The special dialects of law, medicine, divinity, and philosophy have also, in their older strata, become pretty familiar to cultivated persons and have contributed much to the popular vocabulary．Yet every vocation still possesses a large body of technical terms that remain essentially foreign, even to educated speech．And the proportion has been much increased in the last fifty years, particularly in the various departments of natural and political science and in the mechanic arts．Here new terms are coined with the greatest , and abandoned with indifference when they have served their turn．Most of the new coinages are confined to special discussions, and seldom get into general literature or conversation.
Yet no profession is nowadays, as all professions once were, a close guild (行会)．The lawyer, the physician, the man of science, the divine, associat ed freely with his fellow-creatures, and does not meet them in a merely professional way．Furthermore, what is called 'popular science' makes every body acquainted with modern views and recent discoveries．Any important experiment, though made in a remote or provincial laboratory, is at once re ported in the newspapers, and everybody is soon talking about it as in the case of the Roentgen rays and wireless telegraphy．Thus our common speech is always taking up new technical terms and them commonplace.
Special words used in technical discussion ______.