Description in Auction Catalogue:
"Sir Isaac Newton (1642-1727), in blue-lined purple day robe, full-bottomed curling wig. Signed with monogram 'BL' (lower right). Signed, dated and inscribed on the reverse 'Sr Isack [sic] Newton / B Lens Fecit / 1709'. On ivory. Oval, 88 mm. high, turned gilt-wood frame.

The present miniature formed part of series of portraits of writers, philosophers and painters by Bernard Lens. The remaining portraits were also sold alongside the present: Sotheby's , London, 26 November 1992, from the collection of the Marquess of Bristol."

Exhibitions
London, South Kensington Museum, Special Exhibition of Works of Art, 1862, no. 2013 (lent by the Marquess of Bristol).

Litteratur:
E. Farrer, Portraits in Suffolk Houses (West), London, 1908, 'Ickworth', p. 226, no. 139.
G. C. Williamson, The Miniature Collector. A Guide to Collectors of Old Portrait Miniatures, London, 1921, p. 191: 'The most notable point to make respecting Lens is that he appears to have been responsible for the introduction of ivory as a suitable material on which miniatures might be painted […] and there are eight in the collection at Ickworth Park belonging to Marquess of Bristol.'
J. J. Foster, A Dictionary of Painters of Miniatures, London, 1926, p. 186: 'There are eight examples of Bernard Lens' work in the collection of the Marquess of Bristol at Ickworth, including one of Sir Isaac Newton.'
B. Long, British Miniaturists, London, 1929, p. 268: 'The Marquess of Bristol has a few miniatures by Lens […]; some of the miniatures by Lens are copies of pictures.'
M. Keynes, [ed.], The Iconography of Sir Isaac Newton to 1800, Suffolk, 2005, p. 18 (erroneously described as 'oil on canvas').' 3/1-22 Bernard Lens’ miniature portrait of the famous physicist Isaac Newton is based on Godfrey Kneller’s oil portrait painted seven years previously and now in the National Portrait Gallery in London. It was formerly part of a series of miniatures of famous men. Interestingly, Lens chose to paint it on ivory. He was considered to be the first miniaturist in the UK to use this material as his base.