[Grammar] which I had never examined before

[jacob123]

Does the bold part refer to the fact that he had never encountered slate-writing before or does it particularly refer to her slate-writing ?
What is the function of "in" here?

It was our good fortune now to come once again into contact with a really great medium in Mrs. Pruden of Cincinnati, who had come to Chicago for my lectures. We had a sitting in the Blackstone Hotel, through the courtesy of her host, Mr. Holmyard, and the results were splendid. She is an elderly, kindly woman with a motherly manner. Her particular gift was slate-writing which I had never examined before.


"The History of Spiritualism," by Arthur Conan Doyle

 

[Charlie Bernstein]

Does the bold part refer to the fact that he had never encountered [STRIKE]with[/STRIKE] slate-writing before, or does it particularly refer to her slate-writing[STRIKE] of her[/STRIKE]?

He had never examined slate writing before.

(Since it was the first time he had ever met her, we can assume he had never seen her slate writing.)

What is the function of "in" here?

It's short for "in the form of." In Mrs. Pruden, he came in contact with a great medium.

It was our good fortune now to come once again into contact with a really great medium in Mrs. Pruden of Cincinnati, who had come to Chicago for my lectures. We had a sitting in the Blackstone Hotel, through the courtesy of her host, Mr. Holmyard, and the results were splendid. She is an elderly, kindly woman with a motherly manner. Her particular gift was slate-writing which I had never examined before.

"The History of Spiritualism," by Arthur Conan Doyle

There you go!