Huang Changquan (left) with his maternal grandmother and his father, taken in 1990s.[Photo by Li Bing/China Daily]

"The year on the envelope is a clear, stamped 1907. Although the year handwritten on one of the letters appears to be 1917, I now believe that both were actually written in 1907, judging by the letters' contents,"Chen says. (The other letter's dateline does not include the year.)

One thing that is palpable is the sense of attachment Carpentier felt to Dean Lung.

In one letter, dated Sept 17, Carpentier wrote,"I have now more land than I want or can take care of. We are alone... Try to come and see me once more."

In the other, dated Nov 17, Carpentier wrote: "I am glad to know that you would like to visit America again. I wish you could do so."

"The second letter clearly indicates that Dean wrote back upon receiving the first one," Chen says. "In fact, Carpentier must have written Dean Lung another letter in August because in that letter in September he talked about 'my letter of August 4'." Both were signed "Your friend, H.W.C.".

In 1901, 20 days before Dean Lung made his donation to Columbia, Carpentier gave $100,000 to the university, with a letter to Seth Low dated June 8.

"For 50 years and more I have been saving something from whisky and tobacco bills which with fair interest would amount perhaps to the sum of the enclosed check, which I have pleasure to send you toward the founding of a department of Chinese languages, literature, religion and law, to be known as Dean Lung professorship of Chinese," the letter said.