Johann Jakob Herzog

Johann Jakob Herzog , 1805-82, German Protestant theologian. His most important contribution was the founding and editing of the standard reference work Realencyklopädie für protestantische Theologie und Kirche (22 vol., 1853-68), which was published in an abridged English version as The New Schaff-Herzog Encyclopedia of Religious Knowledge (13 vol., 1951-54).

Wettstein, Johann Jakob (1693–1754), NT critic. From 1733 he was a professor at Amsterdam. His edition of the Greek NT (1751–2) included in the critical apparatus many important variants hitherto unrecorded and also the sigla for denoting the MSS in common use since then.

Sederholm, Johannes Jakob (1863–1934) Sederholm fought against illness all his life; at university in Helsinki he chose to study geology as a subject that would enable him to work out of doors. After further studies at Stockholm and Heidelberg he was appointed to the Geological Survey of Finland, where in 1893 he became Director, a post he held for forty years. It was Sederholm's task to try to elucidate the complex rocks of the Finnish Precambrian basement. He initiated a programme of mapping on a variety of scales from 1:10 to 1:10 000 and showed that a number of belts were characterized by a distinct geological history. During the years from 1899 to 1925 many maps and descriptions of these areas were published, thereby establishing a basis for much later research. Many of the gneisses in such areas were largely of mixed aspect, with bands of metamorphic rock interleaved with others of more granitic nature. These Sederholm termed migmatites. He considered them to be the result of intrusion of granite magma into high-grade metamorphic rocks at depth, the granite formed partly by the action of emanations on the older rocks and partly by anatexis. He thus became involved in, and made most important contributions to, the granitization controversy. He was the first to establish the relation between depth of burial and intensity of metamorphism and the growth of new minerals. His fieldwork was backed up by detailed observations of textures and fabrics of metamorphic rocks and he gave to geology a great many textural terms of Greek derivation. He published papers in five languages.

On the basis of detailed mapping and many analyses Sederholm compiled an average composition of a deeply eroded piece of the Finnish crust, giving weighted proportions according to the surface area visible.

Sederholm was not just a geologist. He was a member of the Finnish Diet, for whom he made several missions to the League of Nations. He was also twice chairman of the Economic Society of Finland, and wrote in 1915 The science of work. He was deeply interested in many aspects—social, political, and economic—of the Americas and made several visits to Canada and the USA.

Seven of Sederholm's most influential works were published in book form in 1967 under the title Selected works: granites and migmatites.

R. Bradshaw