ABLE and IBLE .
All English words, without regard to the source from which they have been derived, and those which come from Latin words ending in abilis or French ones in able, take the termination able in English, as, procurable, amendable, desirable, allowable, voidable, available, fordable, incontestable, &c.; but in words from Latin and French words terminating in ibilis or ible, then the ending will be ible in English. For instance: accessible, sensible, defensible, convertible, &c.
In words ending in ce or ge, the final e is preserved before the termination able, for the purpose of indicating the soft sound of the consonant, as in marriageable, chargeable, traceable, serviceable, &c.; but before the ending ible the final e of the primitive disappears, and there is no e before the termination. Examples: deducible, reducible, frangible, &c.
The following list of words in ible is here added; all others end in able:—
accessible
admissible
adustible
appetible
apprehensible
audible
cessible
coercible
collectible
comminuible
compatible
competible
comprehensible
compressible
conceptible
conclusible
congestible
contemptible
contractible
controvertible
convertible
convincible
corrigible
corrosible
corruptible
credible
deceptible
decerptible
decoctible
deducible
defeasible
defectible
defensible
depectible
deprehensible
descendible
destructible
digestible
discernible
discerptible
dispraisible
dissolvible
distensible
divisible
docible
edible
effectible
eligible
eludible
enforcible
evincible
expansible
expressible
extendible
extensible
fallible
feasible
fencible
flexible
forcible
frangible
fusible
horrible
ignoscible
illegible
immarcessible
immiscible[23]
impassible[24]
intelligible
irascible
legible
miscible
partible
passible[25]
perceptible
permiscible
permissible
persuasible
pervertible
plausible
possible
producible
quadrible
reducible
referrible
reflexible
refrangible
regible
remissible
reprehensible
resistible
responsible
reversible
revertible
risible
seducible
sensible
solvible
tangible
terrible
transmissible
visible