Here's a funny (and mean) footnote:
From in Adolf Neubaeur's "Where are the Ten Tribes? II Eldad the Danite" in JQR (1889) v. 1:2. The reference is to the entry on Eldad the Danite by Christian David Ginsburg here (his entries in Kitto's Cyclopaedia are signed C.D.G.).
The background concerns the legend of Eldad ha-dani (whom I was charmingly introduced to in cartoon form as a little kid in the first edition of the Jewish Kids Catalog).
Neubaeur snarks that Ginsburg (who was really disliked by fellow Jewish scholars for his apostasy and pomposity) credulously regards Eldad's tale and travels as true. Of course he does not. However, he does not feel it is necessary to add things like "Eldad claimed" or some kind of disclaimer that, of course, he does not believe it to be anything more than a legend! So a straightforward reading of his piece gives the impression that he is recounting facts. One assumes this is because C.D.G. gave credit to his readers to be able to read an account of a medieval legend without having to be specifically told that it's fiction!
In fact, at the end of the Cyclopaedia entry he writes: "Whatever we may think of his lucubrations on the ten tribes, be it remembred that the greatest Jewish writers of his time and afterwards implicitly believed these stories and others far more marvellous about their lost brethren. Graetz, is, therefore, too severe upon Eldad."
Neubaeur thus read this uncharitably, either because he disliked Ginsburg or because he detected in this last sentence, some scorn on the part of C.D.G. directed toward "the greatest Jewish writers," among them גאונים and ראשונים like אלפסי and רַשְׁ"יִ. (I think the second possibility is less likely, unless it was the first which motivated the second.)
Finally, the reference to Shapira's Deuteronomy concerns the Shapira strips (also posted about here,here and here). Ginsburg played a role in recognizing them as forgeries (some would say, highly, vastly, bloatingly overstated role; the cartoon reproduced below is . . . cartoonish).
In any case, Ginsburg seems to have viewed it at least as potentially authentic and published the text of it and encouraged buzz, seemingly in an effort to promote himself. Neubaeur was opposing the authenticity of it from the start (see this article by him dated August 13, 1883). Take note of how it begins "From the very outset, when I did not as yet know a word of the contents of Mr. Shapira's Moabite Deuteronomy . . . I held it to be a forgery." Truly, he was right, but he might have wanted to see it before holding it to be a forgery!
Given the Sambatyon-Akdamus connection, I suppose this is a Shavuos post.