William Platt (d. 1637)
William Platt matriculated from St John's in 1609, and pursued a legal career, being admitted to Lincoln's Inn in 1612, and called to the Bar in 1619. He was a notable benefactor to his old college, and on his death left large amounts of property in London, and funds for scholarships.
Platt's bequest to the Library
Platt bequeathed his whole library to St John's, allowing works on divinity and medicine to go to his wife Mary for her lifetime. There is some dispute as to whether his books were in fact received, although some 30 to 40 items in the Old Library bear his provenance. These tend to reflect Platt's professional interests as a lawyer, and include several volumes in law French, and one set of laws from the reign of James VI in Scots (1579). They also include several works on alchemy, together with a copy of Richard Record's work on cosmography, The castle of knowledge (1556), with a hand-coloured title-page.
All the volumes given by Platt bear his arms stamped either in gold or blind on both covers.