ii. 42 ABSTRACTS OF CHEMICAL PAPERS. Mineralogical Chemistry. The Occurrence of Nodules of Manganese in Mesozoic Deep-sea Deposits from Borneo Timor and Rotti; their Significance and Mode of Formation. G. A. F. MOLENGRAAFF (Proc. K. Akad. Wetensch. Amsterdam 1915 18 415-430).- Analyses &re given of nodules obtained from the island of Rotti,M INERA LOG1 CAT CHEMISTRY. ii. 43 where they occur in siliceous limestones marls and clay shales. I refers to a nodule from Sua Lain and I1 to a iiociule found in the neighbourhood of Bebalain. SiO,. Fe,O,+Al,C),. H,O,. MnO,. COO. BaO. CaO. Na,O. H,O. COT I. 2.9 2.3 57.7 10.5 0.3 11.7 5.6 1.1 - trace I n the case of 11 calcium oxide1 and alkalis were not estimated. 11. 3.44 1.45 62.06 6.03 - 9-15 - - 8.86 - H. M. D. Iron Ore on Calambaganga Island Philippine Islands.The small island of Calambayanga in the ba.y of Mambulao south- eastern Luzon contains a deposit of iron ore in metamorphosed sedimentary rocks probably of Miocene age which are intruded by andesites and overlie granite and diorite. The ore consists of almost pure haematite with only traces of magnetite and is associated with some pyrites and quartz. Analysis I is of an average sample and I1 of a hand-specimen. SiO,. Al,O,. Fe,O,. FeO. CaO. MgO. Mn02 P. S. TotalFe. \VALLACE E. PRATT (Phdippiite J. S C ~ . 1915 10 A 323-331).- I . . . . 1.02 1.31 97.35 - - - 0.11 0.001 - 64.14 I1 .... 1.29 6.52 68-28 9.22 2-77 0.29 0.09 0.10 0.12 54-94 L. J. S. Iron Ore in Surigao Province Philippine Islands. WALLACE E. PRATT and VICTOR E.LEDNICKY (Philippine J. Sci. 1915 10 A 335-346).-The iron ores of the (' Red Hills," on the north-eastern coast consist of ferruginous (limonitic) clay covering the surface with a maximum thickness of about 20 metres. They are residual weathering products of igneous rocks (apparently peridotites) being of lateritic origin and they resemble the clayey iron ores of Cuba. An analysis gave SO,. A1,0,. Fe,O,. FeO. Cr,O,. S. P. combined. scopic. Total. 1-04 10.56 66-SO 0.36 1.15 trace trace 6.60 13.50 100.01 The average of numerous samples from bore-holes gives 47.40% Fe in the dehydrated ore. Ilvaite and other Minerals from Perda Niedda Oriddese (Sardinia). ERNESTO MANAYSE (Atti R. Accad. Lincei 1915 [v] 24 ii 285-289).-The ferriferous deposits of Perda Niedda contain a number of minerals of which the following are1 described (1) Ilvaite which occurs in pit'ch-black compact o r radiating fibrous masses usually coated with ferric hydroxide hardness about 6 D 3.95 composition as follows H,O H,O hyg1-0 - L. J. S. H,O. SiO,. Al,O,. Fe,O,. FeO. 2.66 29.37 0.67 19.47 27.74 (2) Garnet usually dark gre.en but hardness 6-7 D 3.83 composition SiO,. Al,O,. Fe,O,. MnO. 35.09 2.01 29-82 0.53 3lnO. CaO. MgO. Total. 6.48 13.25 0.51 100.15 sometimes colophony-coloured CaO. MgO. Total. 33.10 0.48 101.03 2*-2ii. 44 ABSTRACTS OF CHEMICAL PAPERS. (3) Wollastonite white radiating fibrous masses hardness 4-5 D 2.86 composition H,O. SiO,. A1,0,. Fe,O,. CaO. MgO. Total. 0.85 50.49 Trace 0.54 47-72 0.51 100.1 1 T. H. P.