50 Years Ago

Sir Charles Darwin writes: “The first estimate of Avogadro's number is due to Maxwell himself”, and expresses his astonishment that Maxwell “should have published a fact of such tremendous importance in a manner that cannot have drawn much attention to it”... The reason for Maxwell's choice seems to have been that he did not claim to communicate anything fundamentally new, but only to discuss a line of reasoning which Loschmidt had published eight years earlier in the Proceedings of the Vienna Academy... It is somewhat surprising that Loschmidt's brilliant achievement has been overlooked so frequently, in spite of Maxwell's full acknowledgement... Avogadro did not even know the order of magnitude of this figure approximately; he died nine years before Loschmidt's paper appeared.

F. A. Paneth

I must plead guilty to the charge of not having made a very deep search of the older literature in connexion with the evaluation of 'Avogadro's Number'... I am grateful to Prof. Paneth for putting this matter right.

C. G. Darwin

From Nature 19 January 1957.

100 Years Ago

The Future in America—a Search after Realities. By H. G. Wells — There has always been in America a wide-spread contempt, not for the law, but for abstract justice, so that even well-minded, influential people do not set themselves to remedy obvious wrong when by doing so they might hurt themselves or their party in the eyes of multitudes of base and busy, greedy and childish, malevolent and ignorant voters. The unfairness of the southerner to the negro is no longer confined to the south, and the crimes of a few negroes exasperate white people so much that they forget the kindly ways of the average man of colour, and thus the negro question is becoming more complex.

From Nature 17 January 1907.