Letters Sent to Dr. F.B. Flinn [Dr. Frederick B. Flinn], October 15, 1931

October 15th, 1931. Dr. F. B. Flinn, College of Physicisns & Surgeons 632 - W. 168th St. N.Y.C. Dear Dr. Flinn: I am herewith sending you one milligran of radium element put up in the Wulf bottle sent us. Before introducing the radium I thoroughly cleaned this bottle and allowed a solution of barium chloride with a little hydrochloric acid to stand in same for several days in order to fix any sulphates that might be in either stoppers or glass, as well as dissolve the readily soluble silica. In making your connections to this bottle it is important that you exercise care that your parts coming in contact with the solution are free from sulphates. I added a little barium chloride to the solution to protect the radium, also a little hydrochloric acid to prevent the radium from being converted to carbonates upon drawing air thru the solution. I trust that you will find this method of preparation satisfactory for your purposes. Very truly yours, Vice President. HHBarker: RH