MINERALOGICAL CHEMISTRY. Miner alo gi c a1 Chemistry. ii. -15 The Genesis of Petroleum as Revealed by its Nitrogen Constituents. CHARLES F. MABERY (J. Awzer. Chent. SOC. 1919 41 1690-1697).-1t has already been shown that the heavier varieties of petroleum in the California Texas Ohio Canada Russian and similar fields are complex mixtures of the denser hydrocarbons with oxygen sulphur and nitrogen derivatives. They all differ widely in composition from the lighter varieties in the eastern territory. An examination of twenty-one specimens of the latter however discloses in every case the presence of nitrogen in amount varying from 0.01 t o 0.4874 so that the conclusion is justified that nitrogen is contained in the petroleum of all the principal oil fields in forms of combination which could have had their origin only in the remains of vegetable or animal bodies.Presumptive evidence has been shown that the associated hydre carbons in petroleum had the same origin. Nitrogen is estimated by Kjeldahl's method on the one hand and by a process which is a combination of the Dumas procedure for nitrogen and the oxygen combustion for carbon on the other. For details of the latter and of the special precautions required in the estimation of such minute proportions of nitrogen in oils the 2**-2ii. 46 ABSTRACTS OF CHEMICAL PAPERS. original paper must be consulted. two methods show very fair agreement. Thc resuits ok)iaiiierl by the H. W. Probable Identity of Peganite with Variscite. LORENZO MOSCHETTI (Atti R . Accad. Sci. T o T ~ ~ o 1917-1918 53 652-656).-The author has analysed and examined physically Breithaupt's peganite ( J . Chem. Physzk 1830 6Q 308) his results indicating the identity of thia mineral with variscite. The composition given by Hermann ( J . p. Chem. 1844 33 287) for peganite is erroneous. T. H. P. Identity of Spangite with Phillipsite. F. ZAMBONXI (Attz €2. A ccad. Sci. Torino 1917-1918 53 47-54).-The spangite described by Mantovani (private communication 1872) is found t o be devoid of magnesium and its crystallographic characters show t h a t it is identical with the phillipsite of the leucitites found in the neighbourhood of Rome. The Minerals of the Valley of Gava in the Voltri Group ; a New Varietyof Talc. EMILIO REPOSSI (Attz SOC. Itnl. Sca. Nut. 1918 57 131-155).-The geology of the region is outlined and a number of minerals described.Crystallography or other features are given of garnet vesuvianite diopside hornblende chlorite titanite apatite pyrite magnetite ilmenite and calcite. Many of these are coated with a mineral which seems to he a new variety of talc and is named gauite after the locality. I t s properties are colour milk-white yellow or green sometimes the calour of nickel salts; lustre in mass velvety on surfaces of individual blades pearly ; structure thin crusts with mammillary surface made up of bunches of flakes. Microscopic study shows aggregate polarisa- tion with the optical properties elongation + ; extinction. parallel; interference colours brilliant; n 1.544 and 1.582 by immersion method about double refraction thus 0.038 ; in all these properties it is similar to talc.It is infusible hefore the blowpipe responds to tests for magnesium and silica and is somewhat readily soluble in hydrochloric acid. T. H. P. Analysis gave Total. SiO,. MgO. FeA. at 110'. above 110' 69.20 28'57 3.23 1.45 6.61 99.06 HgO H,O The water is expelled in two definite stages in the amounts stated. Disregarding the water helow l l O o the revised percentages corre- spond with the formula H,(Mg,Fe),Si,O,,. Gavite differs from talc in the high content of water and i n its solubility in acid. CHEMICAL ABSTRACTS. The Oxidation of Lava by Steam. J. B. FERGUSON (J. Wmhinqtolz Acad. Sci. 1919 9 539-546) .-It is generally sup- posed t h a t water vapour in volcanic gases would have an oxidising action on any ferrous iron present in the lava.Fresh Kilauean lava has been shown t o contain 9.28% ferroiis oxide and 1.92"6 ferrit,ANALYTICAL CHEMISTRY. ii. 47 oxide and this fact might be used as an argument against the presence of a preponde.rance of water vapour in the gases. Very little is known however of the action of steam on silicate minerals containing ferrous iron and a number of experiments are here recorded in which ground Kilauean lava was exposed to the action of water vapour in an atmosphere of nitrogen a t 1000°. As a result of the heating there was found J slight decrease in the ferrous iron content of the rock but this occurred both in presence and absence of steam which behaved as an inert gas. The experi- ments leave no doubt that a considerable amount of ferrous iron when in silicate combinations can exist in the presence of water vapour a t high temperatures.When a sample of the lava was heated strongly in air for two hours the ferrous iron content fell to 1.94% but on again heating in a partial vacuum f o r four hours at l l O O o it rose again t o 3.9%. The bearing of these experiments on the interpretation of results obtained by pumping gases from rocks at high temperatures is eniphasised. ARTHUR M. MILLER (Science 1919 49 541-542).-This meteorite was seen at> midday on April 9th. 1919 passing over north-eastern Tennessee in a course N. 30 W. its progress being noted and in some instances timed by telegraph and telephone operators. It reached the earth in south- eastern Kentucky striking with earthquake violence. A t the time of writing seven pieces ranging from 360 to 2378 grams have been found and their covering of glaze indicates that the splitting off from the main mass occurred at a considerable distance from the ground. F i f t + ~ v o pieces. weighing from less than 30 grams UP to 1800 grams. have been found that are parts of a mass weighing originally about 14 kilos A chemical examination by ALFRED PETER shows the mineral to be mainly enstatite through which is disseminated particle. of nickel-iron and iron sulphides. E. H. R. Cumberland Falls Meteorite. D 3.18. CHEWCAL ABSTRACTS.