Annotatio III §.I: Definition — one substance into another under residual accidents; ORTUS / PROGRESSUS plan
Transmutation reshapes form; Transsubstantiation turns one substance into another while the sensible accidents of the former remain and those of the latter are absorbed — a mutation without precedent.
Plan: ORTUS (causes) then PROGRESSUS (modes and degrees), treated here only for kinship with Consubstantiation.
Latin
Quemadmodum enim Transmutatio rei cujuscunque, transformatio vel exterioris, vel interioris formæ; sic Transsubstantiatio unius præcisè substantiæ in aliam (remanentibus sensibusque expositis prioris, seu transmutandæ, posterioris verò, seu in quam transitio fit, absorptis, nulli saltem sensui obviis Accidentibus) mutationem inaudito prorsus exemplo significat. Hujus Historiam, ob cognationem solùm cum Consubstantiatione, hoc locô, per compendium, tradituri, duas quasi Tractationis partes, constituemus, quarum Prior ORTUM Transsubstantiationis in caussis suis rimabitur: Posterior PROGRESSUM ejusdem in modis gradibusque conspicuum reddet.