Alexander Michie, The Siberian Overland Route from Peking to Petersburg…
“ The real black bread is heavier, and as clammy as if potatoes entered largely into its composition. It is used almost exclusively by the peasants, and is doubly economical, being in the first instance cheap in price, and moreover a very little of it goes a long way, as it resists digestion as long as a hard-boiled egg. The black bread used by the well-to-do classes is a compromise, and is of a black-brown colour, known as demi-blanc. ”
