50 Years Ago

Charles Darwin was in the habit of cutting from his notebooks those pages which were most useful to him when he was preparing to write his large book on natural selection, of which Origin of Species was but an abstract ... Two sets of pages have since been found in the British Museum ... Because the notes are concerned with transmutation of species, most of them refer to examples which illustrate some aspect of adaptive variation. Geographical distribution was very important to Darwin and he recorded examples of species which are peculiar to particular areas and of closely related species living together, such as two bears in Borneo and Sumatra which differ only in the form of a white mark on the breast.

From Nature 8 April 1967

100 Years Ago

In reference to the inquiry of Dr. Walter Leaf in NATURE of March 15 as to the interpretation of a passage of Strabo, the fact may possibly be of some interest that in the island of Mors, in Denmark, bricks are made from a local sandy clay which, after burning, float in water. These bricks are used, I understand, both as a refractory material and for ordinary building purposes ... Their mechanical strength is said to be considerable. The porosity is not obtained by the addition of combustible or volatile matter during moulding. If the expression πηγνυµɛνας, used by Posidonius, be consistent with a process of burning the clay into bricks, and if clays of somewhat similar physical character to that of Mors ... occur in Asia Minor and Spain, an explanation of the passage might perhaps be found in this direction.

From Nature 5 April 1917 Footnote 1