[LB062264A], Letter from Thomas Alva Edison to Sarah L Roys, February 18th, 1896
https://edisondigital.rutgers.edu/document/LB062264A
Transcription
Feb 18 96 Mrs Sarah L Roys 317 West 87th Street New York- Madam:- In reply to your favor I beg to state that I am perfecting the apparatus, the effect of the ray on the bacterial germ of Cancer will soon be known. My own impression is that the ray is very powerful. Yours truly Thos. A. Edison R[andolph].