Critique was published in 1859, after about 14 years of intermittent research. Marx considered it merely a first installment, expecting to bring out additional volumes, but he scrapped his plan in favor of another approach. The result was Das Kapital, subtitled Critique of Political Economy, of which only the first volume appeared, in 1867, in Marx's lifetime. After his death, two other volumes were brought out by Engels on the basis of the materials Marx left behind. Volumes 2 (1885) and 3 (1894) can be properly regarded as works by Marx and Engels, rather than by Marx himself. Indeed, without Engels, as Marx admitted, the whole monumental enterprise might not have been produced at all. On the night of Aug. 16, 1867, when Marx completed correcting the proof sheets of volume 1, he wrote to Engels in Manchester: "I have YOU alone to thank that this has been made possible. Without your sacrifices for me I could never possibly have done the enormous work for the three volumes. I embrace you, full of thanks!"
Published since 1877, Biographical Memoirs provide the life histories and selected bibliographies of deceased National Academy of Sciences members. Colleagues familiar with the subject's work write these memoirs and as such, the series provides a biographical history of science in America. The Online Collection includes more than 1,600 memoirs, including those of famed naturalist Louis Agassiz ; Joseph Henry , the first secretary of the Smithsonian Institution; Thomas Edison ; Alexander Graham Bell ; noted anthropologist Margaret Mead ; and psychologist and philosopher John Dewey .