I just googled 'wirephoto' and the earliest machine was invented in 1895! This was the precurser to the fax machine. Wirephotos were first transmitted inthe middle 1930's. I would bet a small amount that photo negatives were sent via wirephoto early on. That was a crude dot matrix system. All that was developed for the newspaper business. You might ask a historian of that business your question. I took printing in 1954 in high-school an learning some of tnis was part of that education.

I doubt that negatives were sent by wirephoto for news use. Wet prints were made, and if in a rush scanned and transmitted while still wet. The receiver would print out a dot screen suitable for printing on the newsprint press.

I have tried to find the answer to when film negatives were first scanned and digitized. Google has yielded no information and either I am not entering the right question or the info isn't there. I suspect it was about the time one hour developing became popular for 35mm film at drug stores. I also wonder if the big names such as Fuji and Kodak used it in film processing. Can anyone on the forum give me an answer?