Cinchona in quinology to examine the contents of these components in assays. The yields of quinine in the cultivated trees were low and it took a while to develop sustainable methods to extract bark. In the meantime Charles Ledger and his native assistant Manuel collected another species from Bolivia. Manuel was caught and beaten by Bolivian officials leading to his death but Ledger obtained seeds of high quality which were offered to the British who were uninterested, leading to the rest being sold to the Dutch. The Dutch saw its value and multiplied the stock. The species later named as "Cinchona
Bark bread bark is the only part of a tree trunk that is actually edible, the remaining bark and wood is made up of cellulose which animals, including humans, cannot digest. The dried and ground inner bark was added in proportions like 1/4th to 1/3rd "bark flour" to the remaining grain flour. Erik Pontoppidan, the Bishop of Bergen, Norway, in the mid 18th century, recommended using elm, as it helped the often crumbly bark bread hold together better. The bark will, however, add a rather bitter taste to the bread, and give particularly white bread an unappetizing grey-green hue. Another problem is