The 500+ page book "Essays From the Unseen" (which you can read here) is a massive 1885 testimonial by a person claiming to have seen many paranormal wonders. We do not know the author's name, as he puts only a name of A. T. T. P on his title page. As evidence for the paranormal the book must be classified as less than first-class, only because of the author's refusal to give his name. There were very many people in the nineteenth century who claimed to have seen similar wonders, but who boldly gave their full names (and often even their addresses) when reporting their observations. When you have such a situation, the person too timid to give his name must be classified as a second-class witness.
The orb-relevant part of the book comes on page 45, when the author states this:
"On one occasion I was sitting at No. 15, Southampton Row, in the company of several others, the Sensitives present being Miss Wood, and a Lady of the name of Fairlamb, and Mr. Herne, a well-known medium, when the figure of a small negro child of four or five years of age, whether boy or girl I did not know, gradually formed from a Ball of light at my feet. I put my hand on the crisp Negro hair of the child. This figure afterwards disappeared in the same manner as it formed, that is, gradually."
We should not exclude this claim merely because of its fantastic-sounding claim, as many similar wonders were reported by witnesses who gave their names and all the details of their observations, including relevant dates and places of observation. You can read about some of their accounts by looking at the 11 posts here.