Letters Sent, March 17, 1926

March 17, 1926. Bureau of Construction and Repair, Navy Department, Washington, D. C. Dear Sirs: Reference: No. 1808-A686 (s) 4/1 Precautionary Neasures Necessary in Connection with the Use of Radium Luminous Material. We acknowledge your letter of the 16th by Captain G. H. Rock under the above subject. Dr. Frederick B. Flinn of Columbia University, College of Physicians and Surgeons, 437 West 59th Street, New York City, Institute of Public Health, has made a very thorough and painstaking investigation of this subject. A report of his findings will probably be available within the next week or ten days. Dr. Flinn has been working for a mumber of months and has investigated conditions in a number of application plants in addition to carrying on elaborate experimental work. As soon as this report is received, we will be glad to mail you a copy. He has not foum evidence that radiosetive elements used in luminous compounds or the wine sulphide base could be held accountable for the cases of jaw necrosis that have been reported. Since the first reports appeared, we have vigorously enforced in our Plant the rule that the operators must not place brushes in their mouths. This is unsanitary whether or not luminous material is ever found to be harmful. Yours truly, President.