The Chemist of Berlin, The Horseman of Ulster, The Farmgirl of the Kingdom of Mourne by Boni Thompson is a History Paperback Book. Poison gas.Clara Immerwahr, wife of its famed inventor, Fritz Haber.George McGivern, an Ulsterman, and horse breeder/farrier who joins the Horse Guards and suffers its effects.Ellen Rogers, his wife, a farmgirl and domestic servant, from the Mountains of MourneTheir stories demonstrate how war affects both the great minds of the age as well as the most ordinary of lives. The story has been based on scholarly research, family history, information from local historians, as well as letters and photographs of the main characters.