From the INTRODUCTION.
The object of the present study is to examine — morphologically and semologically — appellative compound substantives, both of whose members are substantival, occurring in the different periods of the English language.
In defining the term compound word two things are needful — in the first place to differentiate them from syntactical word-groups, in the second place to differentiate them from simple words. The latter demarcation is simple enough, theoretically; as to the difficulties attending the carrying out in practice of the principles established, see Chap. i. NOREEN puts it thus (Vart Sprak VII 20): »a compound word is such a word as can be broken up into parts, which severally refer to some independent sense-unit existing in the languages. By this definition derivatives as well as obscured compounds are excluded. As for distinction from derivatives see Paul, Prinzipien p. 322, Sweet, N. E. Gr. § 69, TOBLER, Wortzus. p. I, Brugmann, Grundriss p. 5, and others.
The differentiation from syntactical word-groups is more difficult. NOREEN (op. cit. VII 36 foll.) has made a critical examination of older opinions as to the relations between compounds and syntactical groups and rejects them all on account of their shortcomings. By way of his criticisms he arrives at a definition of his own, — a very original one, which is implied in his definition of the term «word» (VII 13): »a word is an independent sense-unit, which, in regard to sound and meaning, is apprehended by our linguistict instinct to be a unit, either because it cannot at all be subdivided into smaller sense-units, or because, even if it can, one does not reflect, or at least does not wish to reflect, on the special meaning of these smaller sense-units.» This definition actually embraces all compounds, in contradistinction to those of older grammatical writers, which, on account of their greater or lesser inaccuracy, admit either too much or too little. Paul and Brugmann, for instance, draw the limits too narrowly in regarding the criterion of a compound to be the circumstance that »das Ganze den Elementen gegenüber, aus denen es zusammengesetzt ist, in irgend welcher Weise isoliert wird». And SWEET still more so, since he requires of a compound both semological and formal isolation. NOREEN emphasizes that there actually exist compound words which cannot be said to present isolation in any respect whatever, as is proved by his examples "G. ansehen, um . . willen, Sw. for . . skull, sta bi." In English, too, these compounds are very common, e. g. "lady's maid, on account of, out of doors."