In order to complete this part of the case, it is necessary to add that the M.E. ē which results from A.S. ēa is ALWAYS open[[31]].
[§ 33]. A similar ambiguity occurs in the case of a long e which we should expect to be close. Here again we must distinguish between two kinds. The A.S. ēo yields an M.E. ē which is ALWAYS close; as in dēop, deep, M.E. déép. Again, there is an A.S. ē which results from mutation, as in A.S. blēdan, to bleed, from blōd, blood; and the resulting M.E. ē is ALWAYS close, as in blēden (bléédən), to bleed.
But there is also the UNSTABLE vowel in the M.E. y-sēne, visible. Of this word the A.S. forms are various; we find gesīene, gesȳne, gesēne, all three. Of these, gesīene is the earlier spelling of gesȳne, and may be neglected; but gesȳne and gesēne still remain. Gesȳne is the usual A.S. (Southern) form, whilst gesēne is Midland and Northern. From the Midland gesēne came M.E. ysēne (iséénə), with close e, regularly; and this is the form which Chaucer usually adopts. The A.S. gesȳne would have developed regularly into M.E. ysȳne (isiinə), just as the A.S. mȳs answers to M.E. mȳs, mod. E. mice. But the y-sound was difficult of treatment, as the true sound (yy) was
lost; and Ten Brink has observed a corresponding variation in the development of A.S. short y, which became sometimes short i and sometimes short open e in M.E. In the same way, I should suppose that this A.S. long y corresponded to a Kentish long open e; thus producing M.E. ysēne (isèènə), in which the e was open. There is a remarkable example of such a variety in the development of the A.S. fȳr, fire. This usually became M.E. fyr (fiir), with long i; but in Troilus, i. 229[[32]], we have the remarkable form afere (afèèrə), on fire, riming quite regularly with were (wèèrə), were (from A.S. wǣron), and with stere, to stir (from A.S. styrian). Indeed stere, to stir, is really another example of the like development, since the e in it is merely lengthened from an A.S. short y.
[§ 34]. Summary. As this investigation has run to some length, I here give a summary of all the above results.
Open and close ō. 1. The M.E. open and close ō have resulted in mod. E. sounds which are still kept apart; cf. M.E. stòòn and M.E. dóóm with the mod. E. stone and doom.
2. A.S. ā produced M.E. open ō. A.S. o, when lengthened, also produced M.E. open ō. But the two M.E. sounds somewhat differed, and Chaucer avoids riming them together. The few exceptions are noted above; the commonest of these being due to the variable treatment of the words mōre and before.
3. A.S. and Icel. ō produced M.E. close ō. Chaucer avoids riming the close ō with the open one; the chief exceptions being when the vowel-sound is final, and in other cases where rimes are scarce.
4. The different spellings of the mod. E. sea and see, now pronounced alike, answer to the different sounds of the M.E. form see. If the ee was open, it meant the sea; if it was close, it was part of the verb to see.
5. The A.S. ēa produced M.E. open ē.