I recently re-encountered this ampersand (apologies for reproduction quality; it comes from an older microfilm that I have of a ms that is not yet online) which connects the ‘e’ and ‘t’ of two words.
The fuller phrase runs aduersus nos de terra nasci iussum est. In this manuscript word-division is not consistent. Some lines show little spacing between words; others reveal more-or-less regular division. That deterra is written without word division (in fact, aduersusnosdeterra is all written without preceptible spacing) is not surprising. But the ligature of ‘et’ (or ampersand) caused me to trip over the words when reading.
My impression (without doing a thorough study of the whole manuscript or contemporaneous manuscripts) is that & elsewhere is used for the word et or at the end of a word (useful in the endings of third person singular imperfect subjunctive verbs, for example) as in soluer& which appears in the line above and below.
So my question is: does anyone know of work done on ligatures that cross words (lexical boundaries)? The set of words where is can occur is somewhat limited. For example (for Latin; mileage varies for other languages and their writing traditions), those words ending with e and beginning with t, ending with c and beginning with t (e.g. nec tonans?), ending with s and beginning with t (e.g. es tu?). Is it possible that these examples can address the writing/copying process in terms of visual units rather then or in addition to or together with the sense units (or transfer units) that Parkes described in discussions of copying from an exemplar. Alternatively, is it possible to link or compare this writing practice to/with present studies that posit the syllable as a unit for young (as here)? The cross-word ligature indicates a visual unit that is also a sense unit (and the execution of the ligature is has little to do with the reading/processing of the exemplar but more to do with facility with the ampersand).
I did a quick look through Saenger, Space between Words. While he defines a ligature as a stroke that links two discrete letters within or between words (434), the examples that he gives (so far as the index indicates) occur within words. For example, ct, st and et are described as intraword ligatures (21) and et is discussed in terms of the compaction achieved at word ends by using e-caudata and the ampersand (29).