Normally you'd cite only the paper you're interested in, not the entire journal volume. This is the same logic as in your other question. (And if, for some reason, you were to cite the entire volume, it doesn't make much sense to list as author(s) only the author of a single article within it. Listing the editors would make more sense, just like is done for edited volumes with chapters written by multiple authors.) A bibTeX entry might look something like
@article{proth1878theoremes,
title={Th{\'e}oremes sur les nombres premiers},
author={Proth, E.},
journal={Comptes rendus hebdomadaires des s{\'e}ances de l'Acad{\'e}mie des sciences},
volume={87},
pages={926},
year={1878},
url={https://www.biodiversitylibrary.org/item/24818#page/932/mode/1up}
}
The journal in question has seen many names, splits into sections and abbreviations over the years. A reasonable abbreviation for this iteration might be "C. R. Hebd. Séances Acad. Sci.", but there is also the less specific "C. R. Acad. Sci.". Sometimes "C. R." is expanded to "Comp. Rend.". This might be useful to know if you intend to publish somewhere that insists on using journal abbreviations in the reference list.
In the bibTeX entry above, I've listed the author as "E. Proth". I'm pretty sure the 'M' in "M. E. Proth" means the honorific 'Monsieur' and isn't part of the name. You'll find the same 'M' in many other entries in the volume, and in some cases also 'MM' for the plural (Messieurs).
Finally, there's the question of the 'E' in "E. Proth". Certainly, the theorem has since been attributed to François Proth, and cited as if published under "F. Proth". Perhaps the 'E' is a typo, or maybe Proth published under multiple initials names? In general, I think it's clearest to cite it as originally published, and add a note if you can find more historical details.