His Pentagloss Lexicon, and his tragedy, justify the high character the Oxford antiquary has given him. "He was," says Anthony Wood, "the rarest poet and Grecian that any age or nation produced." His play was acted several times in Trinity College Hall, and so admirably and so pathetically, that a gentlewoman present thereat, upon hearing the last words, "sequar, sequar," so hideously pronounced, fell distracted, and never after recovered her senses. The first edition was a surreptitious one, in small 12mo., 1632, which induced the author to publish a correct copy in the same year, having a well engraved frontispiece, and the title of, Roxana tragaedia a plagiarii unguibus vindicta, aucta, et agnita ab authore Gulielmo Alabastro. Londini, excudebat Guilielmus Jones, 1632. This is followed by a Latin dedication to Radulphus Freeman, Eques Auratus, where in he complains, that after his tragedy, the work of two weeks, had, accordingly to his wishes, died a natural death, some plagiary brought it out from its obscurity, and caused it to be acted as a performance of his own. To which he added more faults, that he seemed to strive with him which of the two should commit most. He then says, "Quid facerem? An paterer vagari librum sceleratum, qui nomen meum si non a fronte, tamen a tergo gereret? Vel senex septuagenario proprior, Musas juveniles procarer, ingenio indoles, et fetum juventutis a cura senis non deponerem. Revocari igitur ad calculos plurima quae admisset crimina, vel ex ingenio proprio, vel pravo amaneuensium consortio." Both editions are very scarce: the later one, the true edition, is seldom, or ever to be met with. A manuscript copy exists in the University library.