If you are interested in Spiritualist and occult writings from way back when, then you’ll probably like the International Association for the Preservation of Spiritualist and Occult Periodicals (IAPSOP). The site covers the time period from the 1840s to the start of the Second World War.

I explored the August 1882 issue of Gallery of Spirit Art, and found a poem about spirit art that was written through mediumship (page 10). Interesting reading. The site is primarily intended for historical research, and if you want to know more about how to use the materials, including copyright, check their practices page.

According to the IAPSOP site, the materials are provided in curated, digital form, already indexed, suitable for online reading, scholarly use and citation. They receive no funds from any organization, and rely exclusively on the contribution of material, labor and money from users. So help them out, if you can.