Page 234. " and sleek little Astrakhan coat "
 Astrakhan is a type of loose curled fur made from the coats of young Karakul lambs, once bred near the city of Astrakhan in south-western Russia. Karakul sheep, which usually have black or grey coats, originated in Central Asia, near Bukhara in modern Uzbekistan. Hats made from Karakul pelts were often seen gracing the heads of the Soviet leaders, like Brezhnev; the hats are popular with men in Central Asia, including the current President of Afghanistan, Hamid Khazai.
Page 236. " that kindly Pliny was held in affection by the poor folk of Comum and Tifernum "
 A reference to the Roman Pliny the Younger (61-c.112 AD), nephew of Pliny the Elder. Pliny was born in Novo Comum in Italy, where Como is now; later in his life he had a summer house near Tifernum in Tuscany. Pliny the Younger was a writer and lawyer, a prominent member of first century Roman society who today is probably best known for his account of the eruption of Mount Vesuvius, described in a letter to the historian Tacitus.
Page 238. " he clung to it with a fierce Pavlovian tenacity "
Ivan Pavlov
Public DomainIvan Pavlov
 A reference to the work of Ivan Pavlov (1849-1936), a Russian scientist famous for his study into classical conditioning. Pavlov performed an experiment in which he rang a bell before feeding dogs; soon the dogs began to salivate at the sound of the bell, associating the noise with food. This he called a conditioned reflex; such responses are unconscious, and automatic.
Page 250. " skulking around in rags like Howard Hughes "

 Howard Hughes (1905-1976) was an eccentric American entrepreneur who made his fortune in various different industries including aviation, film, and engineering. He had obsessive-compulsive disorder, which led to his famously reclusive and eccentric behaviour later in life; at one point he closeted himself inside a film studio for four months, only eating chocolate bars and milk. He had a fear of germs, and would use tissues to shield himself when he touched things or picked them up. Martin Scorsese's film The Aviator, starring Leonardo DiCaprio, is based on Hughes' life.