# Diphtherite: What is it and what is the difference with Diphtheria?

My brother and I are researching our family tree, and in our extended ancestry, there is a person who is registered on their death certificate to have died June 1858, of diphtherite. I wondered if it was the same as diphtheria and did some searching online.

Apart from loads of hits on diphtheria as a suggested alternative when just searching "diphtherite" (with the speech marks) in Google, I came across a piece called An Essay on Diphtheria by W. Davis MD of Paris, Illinios in a large 1861 book called The Medical Examiner; a Semi-monthly Journal of Medical Sciences, Volume 2 edited by Nathan Smith Davis MD and Frank W. Reilly MD and it has me confused.

First of all, right at the beginning (Page 79), it says (emphasis mine)

Diphtheria or diphtherite has occupied much space in the medical journals, and engaged much attention in the past year.

So, initially I thought, yes it is the same. But, later the essay says (Page 85)

Our patients did not die of diphtheria, they were killed by diphtherite.

and

the way to cure diphtheria is to cure diphtherite.

Admittedly I was just skimming the essay for now using highlighting of diphtherite provided by Google Books, but can an someone clear this up as I cannot seem to find anything that clearly defines the difference. Or am I missing something with the skimming through?

• Potentially relevant: etymonline.com/search?q=diphtherite
– Ian Campbell
Jan 12 at 17:02
• Thanks for that @IanCampbell so it may be the same after all.
– Chris Rogers
Jan 12 at 17:05
• @ChrisRogers definitely the same disease in reality, but at the time there was only the beginnings of germ theory (Pasteur was 1850s; Koch 1880's) and diseases were only just being identified and categorized as separate causes. I suspect (no evidence) that the diptherite (ite suffix means associated with) is actually the pseudomembrane that is caused by dying tissues in the throat as a result of the infection. i.e. in your last quote - cure for diphtheria is to cure the pseudomembrane. No recognition of the cause/effect pathway.
– bob1
Jan 12 at 19:09
• Agree with bob; it also seems from the context of just this author's writing that they are treating the "diphtherite" as the signs of infection found in the throat, versus "diphtheria" as a disease in the blood. That is, they're talking about failed attempts to treat the disease systemically through the blood whereas the obvious problem to them is this growth in the throat. It's not clear to me whether this distinction in terminology was common at the time or just to this author. Jan 12 at 19:39
• Although it's not off topic here, I think it would find better answers from historians so I am migrating it as @ChrisRogers suggested. Jan 12 at 20:23