Michael Heidelberger with delegates at the Indian Science Congress in Calcutta, India

Heidelberger with delegates to the Indian Science Congress, held in Calcutta in early January 1952. Fourth from the left is Arthur Stoll, assistant of Richard Willstatter at the University of Zurich when Heidelberger studied there in 1911-1912. To Heidelberger's left is the vice chancellor of the University of New Delhi. Heidelberger was selected as a replacement for Linus Pauling, who was unable to attend the Congress for medical reasons.

Lectures at the Congress were held in a large tent, and, however technical, were open to the public. They were attended by entire families, including grandparents and young children.

Heidelberger spent six weeks in India, and had dinner with Prime Minister Jawaharlal Nehru, during which the two did not discuss science but U.S. foreign policy. He also seized the opportunity to study the immunological properties of elephants, an idea first proposed, half jokingly, by Oswald Avery when he had become frustrated with the small amounts of antiserum produced by rabbits, the standard experimental animal in immunology. Heidelberger injected human gamma globulin into the ear vein of a work elephant, and found that the animal was indeed a good producer of antiserum to the human gamma globulin.