
Samples of cinchona bark
1930-1931
1930-1931
1938-1940
1926
1935
1930
1937
1938
1933
1938
1924
1939
1933
1931
1937
1935
1925
1925
1940
1924-1927
1938-1939
1936-1939
1934-1940
1922-1924
1924
1925-1935
1925-1930
1935
1921
1935-1936
1934-1940
1925-1930
1921-1934
1921-1930
1932-1933
1922-1925
1923
1923
1925
1928
1938
1938
1933
1925
1940
1934
circa 1940
1926-1934
1925-1935
1926-1928
1801-1892 (prepared); 1946 (element replaced)