I'll tell you up front that "My dear Sister" is Edna B. Humphrey - or at least it is her box of 'stuff' I purchased. I found it rather interesting that W. E. Humphrey is living in Washington, D.C. He is writing to his sister in answer to letters she had written to his wife, Helen. He mentions both he and his wife have fully recovered from their attack of tomaine poisoning. Tomaine poisoning? OK, I just cannot let that pass without mention.
Good ol' Wikipedia (sometimes called the undergraduates encyclopedia) has my answer. Ptomaine poisoning is a reference to food poisoning. In particular, it is an archaic term referring to alkaloids created as food decays. These alkaloids, it was believed, caused food poisoning. This was disproved with the discovery of bacteria and bacterial toxins as the cause of food poisoning.
It was a pretty easy thing to find out who the writer of this letter was. William E. Humphrey was a U.S. Representative from the state of Washington. He later was appointed to the Federal trade Commission by Calvin Coolidge. He was reappointed to the FTC in 1931. This is where his problems started. He was a conservative Republican and immediately at odds with the new Roosevelt administration. FDR removed him from the Commission in order to appoint someone more in line with his administration's views.
William Humphrey promptly sues the Roosevelt administration regarding being removed from his position for political reasons. The case ends up being heard by the Supreme Court. Unfortunately for William, he doesn't live to see his law suit to the end. He dies on 14 Feb 1934. I found the picture of William Humphrey at Wikipedia.
So let's see what else is in this box of stuff...