The structure of these derivatives is better seen in some of the
other Teutonic dialects than in the English or the Anglo-Saxon,
in which the affix is reduced to a mere consonant. Thus, for Eng.
_depth_ the Gothic has _diupi-tha_; for _heigh-th_, _hauhi-tha_.
In Old High German the affix _-tha_ becomes _-da_, and we have
_heili-da_ corresponding to Eng. _heal-th_; _strenki-da_, to
_streng-th_; besides a great number of analogous forms, such as
_evi-da_, "eternity" (from the same root as _ever_; compare Lat.
_aetas_ for _aevitas_). In modern German comparatively few of these
derivatives survive; and in those that do; the _-da_ of the Old
German has passed into _-de_, as in _ge-baer-de_, the way of
'bearing' oneself, behaviour; equivalent to Latin _habi-tus_. The
modern German equivalents of _bread-th_, _leng-th_, are _breit-e_,
_läng-e_; but in some of the popular dialects the older forms
_breite de_, _läng-de_ are still retained; and in Dutch _warm-te_
corresponds to _warm-th_, and _grôt-te_ is _great-ness_. When we
recollect that _th_ or _d_ in the Germanic languages represents in
such cases the _t_ of the Greek and Latin (compare Gr. [Greek:
me/lit (os)], honey with Goth. _milith_; Lat. _alter_ with Eng.
_other_), we cannot help seeing how analogous is the formation of
the class of words we are now considering to that of Latin past
participles (ama-tus, dic-tus, audi-tus). In the case of those
abstracts that seem to come more naturally from an adjective root
than from a verb, we can conceive the adjective formed on the
analogy of the past participle; just as there are in English
adjectives having no possible verbal root, yet simulating past
participles; as _able-bodi-ed_, _three-corner-ed_. The abstract noun
would appear to have been originally distinguished from the
participle, or participial adjective, by some additional affix, as
in lec-t-io. In Greek and Latin this additional affix very often
consisted in a reduplication of the formative element _t_, as if for
the purpose of denoting multitude, generality; as in Greek ([Greek:
neo/-têt-os]), Latin _juven-tut-is_, _sani-tat-is_. It is not
impossible that Goth. _diupi-tha_, O.H.G. _heili-da_ are
abbreviations of _diupi-tha-th_, _heili-da-d_, just as Lat.
_sani-tat_ has dwindled down in modern Ital. to _sani-tà_.
In a great many words essentially belonging to the same class both
in meaning and in mode of formation, the _-th_ has, for the sake of
euphony or from other causes, given place to _t_ or _d_. Thus _mood_
corresponds to Goth. _mo-th_, and means a motion (Lat. _motus_) or
affection (of the mind); _blood_, to Goth. _blo-th_; _theft_, is in
Ang. Sax. _theof-th_. _Mur-ther_, from a root akin to Lat. _mori_;
_burthen_, from the root of to _bear_, are of similar formation,
with additional affixes.