This is Fleming Stone #37.
About the author: Carolyn Wells (1862-1942) was married to Hadwin Houghton, the heir of the Houghton-Mifflin publishing empire. Like Mary Roberts Rinehart, being in a publishing family created an easy pipeline for getting her works into print. She wrote a total of more than 170 books. See this Wikipedia article.
Major Characters:
*Justin Leonard, a lawyer
Myrtle Leonard, his touchy-feely wife
Nathaniel Bancroft, millionaire portrait subject
*Eleanor Bancroft, his daughter
Ellis Kane, a painter
Ann Murdock, a painter
Alonzo "Lonny" Abbott, writer
Sammy "Pinky" St. Clair, a painter
*Mark Mason, art critic, the victim
Emily Mason, Mark's mother
Lily Dana, Mason's fiancée
Ellen Talcott, Lily's chaperone/companion
Hal Deming, next in line for Lily Dana
Fleming Stone, private investigator
*on the portrait selection committee
Locale: New York City
Synopsis: Millionaire Nathaniel Bancroft is going to sit for his portrait, and a committee has been formed to select a painter for the lucrative commission. The committee consists of Nathaniel's daughter Eleanor Bancroft, lawyer Justin Leonard, and art critic Mark Mason. The painters being considered are traditionalist Ellis Kane, modernist Ann Murdock, and bohemian "Pinky" St. Clair. At a gathering at Kane's studio, the principals are seated (mostly) at a round table, looking over Kane's collection of miniature paintings:
Suddenly Mason cries out that someone has stepped on his foot, although no one saw this happen. He turns ill immediately and soon is dead. There is no apparent cause, but an autopsy shows poisoning by strophanthin, a cardiac stimulant.
Review: