[I accidentally deleted this post, and so I am now re-posting it; apologies if you get an alert to this post if you have already read it before. I have, however, added a very short addendum]
As discussed in a previous post, the British Library has the small but important collection of illuminated cuttings and leaves formed by John Malcolm, of Poltalloch, depicted above.
I have begun to prepare a detailed list of the provenances of the items in the collection, but I begin today with some general background.
"It was Malcolm's enormous wealth that enabled him to become one of the leading collectors of his day. In 1860 he purchased en bloc the remarkable collection of Renaissance drawings formed by the great connoisseur J. C. Robinson, then superintendent of the art collections of the South Kensington Museum, later the Victoria and Albert Museum. The great strengths of this core collection of some 554 sheets were the works of Italian Renaissance masters, including thirteen drawings attributed to Leonardo da Vinci, twenty-three to Michelangelo, and thirteen to Raphael ... On Robinson's advice Malcolm continued to add to his collection ..." (Oxford Dictionary of Biography [online with subscription])
J.C. Robinson was the author of the catalogues of John Malcolm's collection of drawings and illuminations, and had also been editor of the catalogue of the 1862 exhibition at the South Kensington Museum, to which Robert Holford loaned the group of single leaves and cuttings later acquired by Malcolm (as discussed in the previous post).
In a series of entries on the BL's catalogue of illuminated manuscripts, Anne-Marie Eze noted that John Malcolm probably acquired most of his illuminations between the publication of the catalogue of his collection in 1869 (from which they are absent), and the second edition of 1876 (in which 15 are present).
J. C. Robinson, Descriptive Catalogue of Drawings by the Old Masters, Forming the Collection of John Malcolm of Poltalloch, Esq. (London, 1876) [Google Books]
This does indeed seem to be very likely, because the Preface to the 1876 second edition states:
"Appendix II. contains a description of certain beautiful Italian illuminations, which have been added of late years to the collection." [emphasis added]
It is tempting to imagine that it was the Burlington Fine Arts Club exhibition of illuminated manuscripts in 1874 that inspired Malcolm to extend his collection beyond its core focus on prints and drawings (and it cannot have hurt his acquisitive nature that he had received £175,000 the previous year from the sale of his Australian cattle stations, as mentioned above):
The first 161 items in the exhibition catalogue are codices, but they are followed by about 50 single leaves and cuttings, including (just) one loaned by Malcolm:
BL, Add. MS 35254Q [Source]
The fact that this is one of Malcolm's few illuminations that was not from the Holford collection, suggests to me that Malcolm's acquisition of the Holford illuminations post-dates the exhibition. If so, we can narrow the date of Malcolm's acquisition of the Holford illuminations to the years 1874-1876.
Malcolm was probably encouraged to consider consider Renaissance drawings and medieval manuscript illuminations as part of a continuum, by the presence in his collection of a cutting from a Psalter with a miniature/drawing attributed to Fra Angelico, of which these are the verso and recto, respectively:
Malcolm already owned this when the first edition of his catalogue was published in 1869:
The "Collection (W)" on the last line of the description indicates that he got it from the collection of Dr Rev Henry Wellesley (d.1866) [Wikipedia], in whose posthumous sale it was lot 123 (where it was bought for £8 8s by "Whitehead", doubtless Thomas Miller Whitehead, whom we have now encountered in several past blogposts):
Edit, 1 Dec 2020
I have now also bought a copy of the exhibition catalogue, Landmarks in Print Collecting: Connoisseurs and Donors at the British Museum since 1753, ed. by Antony Griffiths (London: British Museum Press, 1996), which has a chapter on Malcolm and Mitchell.