Letters Sent to Ed Ingraham, June 4, 1925

June 4, 1925. lir. Ed. Ingraham, c/o The 3. Ingraham Company, Bristol, Conn. Denr lir. Ingraham: It is true that an operator who formerly worked in our Application Department developed soon after leaving what is reported to be a stubborn type of Jaw necrosis following the extraction of a tooth or some teeth. Jaw necrosis I am told, results from a good many casses. It seens, however, that throe, possibly four, former operators developed similar conditions although these cases developed from one and a half to four years after the operators left our employ. Investigation has disclosed nothing in the medical literature reporting a similax condition although luminous material application has been common comercially abroad since 1913 and in this country since a year or tiro after that. It seems almost incredible that if the occupation was injurious it should not have appeared and been investigated and reported in the medical press before this. We are strictly enforcing the rule that operators must not moisten brushes with their lips and while I do not Jmow what investigation Dr. Hoffinn has made, I un quite convinced that he would not have made his speech at Atlantic City recently had he thoroughly investigated the industry in this country and abroad. Yours truly, President. ARoeder-EDI