Material from the interaction of the Siam Society and the Royal Asiatic Society. These are:
- Letter from the President, Royal Asiatic Society, to H.H. Prince Dhani Nivat, President, Siam Society, to congratulate the Siam Society on its Jubilee. Typed, dated 18 February 1954.
- "Siam Society - 75 years" - printed pamphlet produced to mark the 75th anniversary of the Siam Society in 1979.
- Letter from D.J. Duncanson, Director, Royal Asiatic Society, to The President, Siam Society, to send the commemorative publication celebrating 150 years of the Royal Asiatic Society. Typed, dated 27 May 1980.