Codex 61, or Montfortianus, derives its name from one of its former possessors, Rev. Thomas Montfort, D. D., of Cambridge. It is now at Trinity College, Dublin. This manuscript is of special interest among the cursives from the part it has played in the discussion of the interpolated verse in the First Epistle of St. John (v. 7), the verse of the " Three Heavenly Witnesses." It contains the whole New Testament, written apparently by three or four different hands, and is composed of four hundred and fifty-five paper leaves, only one of which is glazed. This single glazed leaf is the one containing the verse mentioned. A witty Irish prelate, quoted by Scrivener, [Plain Introduction, p. 173, Note.] said of this coincidence :—
We often hear that the text of the Three Heavenly Witnesses is a gloss, and anyone that will go into the College Library may see as much for himself.When Erasmus published his two earliest editions of the New Testament he did not insert this verse, and was severely blamed for the omission. His defence was that it was not found in the manuscripts used by him, and he pledged himself to insert it in his revisions if any Greek copy could be found containing it. In his third edition he printed the verse (in 1552), saying that he found it in a Codex Britannicus discovered in England. The verse, as printed by Erasmus, is in exact verbal agreement with the text upon this glazed leaf of Montfortianus, and it is wholly agreed that the Codex Britannicus must have been the one now known by this name. The earliest owner of the manuscript whose name we know was Froy, a Franciscan friar, from whom it passed to Thomas Clement; next it was owned by William Chark; then by Montfort; then by Archbishop Usher; from whose hands it came into possession of the college in Dublin. It will be noticed that the name of the third owner was William Chark, and when we come to speak of the next cursive it will be found that he was also at one time the possessor of the Codex No. 69. In 61 the Revelation has been thought to have been copied from 69, when both were in the hands of Chark. Certainly the margins of both copies bear many notes in his handwriting, and it would have been a strong temptation to have had the opportunity of completing 61 by adding the Revelation from so good a source. As it stands, the text of this added Scripture is found to be of higher critical value than any other part of the volume.
By way of appendix, I would like to point the reader to a work that collated this codex. In the introduction, at page 61, the collator suggests that the portion of the manuscript that includes the Johanine Comma is a copy of Codex Lincolniensis, and that the Comma is an unauthorized interpolation to that copy (link to page).