A.—No. 16.

Its temperature requires to be raised to 260° Fab. before its vapour inflames ; and eyen with a wick it does not burn so freely as common animal oils. The specific gravity is very high as compared with other hydro-carbons, being no less than 962 (water being 1000) or 14| degrees of Gesner's hydrometer scale. There does not appear to be any instance on record of a rock oil having so high a, specific gravity, the usual range being from "814 to 930 for crude oil. It may be explained that all the varieties of petroleum are composed of carbon and hydrogen and only differ in their quality according to the proportion which these two elements bear to one another, the heavier, and inferior oils for illuminating purposes having the larger proportion of carbon. There is therefore no test of the quality of the oil which is so reliable and so easy of application as that of the specific gravity, and the above results are quite sufficient to show that the samples of oil examined have a much larger proportion of carbon in their composition than the common petroleum from which the kerosene of commerce is manufactured. This was still further proved by the examination of the oil by distillation as in the production of kerosene. A measured quantity of the crude oil was distilled with a very gentle heat which was gradually raised until 80 per cent, of the original quantity was obtained in the receiver, which is about the average proportion of kerosene obtained from the American petroleum. The oil obtained which had a faint yellow color and pleasant odour, was of specific gravity '930, which is denser than the commercial proof that has been fixed for heavy lubricating oils ('927). As the lighter oil would distil over first and at a lower temperature, the experiment was repeated and the process stopped when 25 per cent, of the original quantity operated on had been obtained in the condenser. The distilled oil obtained on this occasion had a specific gravity of -889 or slightly over the proof fixed for light lubricating oils ("881). By further experiments it was found that the lightest oil that could bo drawn over had the specific gravity of '874 and of this quality only a i oz. could be obtained from 12 oz. of the crude oil after it had been carefully purified by filtration. The next lj oz. obtained had a specific gravity of '893, and the next ounce "917, which would give to the remainder of the 80 per cent, of distilled oil obtained in the first experiment a specific gravity of '941. The first two samples were quite clear and colorless, but the last had a pale yellow tinge. The average specific gravity of the 2i oz. thus obtained from the original quantity of 12 oz. was "900, or that of a lubricating oil of medium quality, while the oil left in the retort had a consistency of tar. The ordinary density of the kerosene of commerce should be '819 (although it is often made lighter, in order to improve its color, which however renders it liable to explode), and it has been found impossible to obtain oil of this low density from Taranaki petroleum. The lightest distilled oil which was obtained burns freely with a wick, but has a lurid flame and, though not adapted for use in the ordinary kerosene lamp, might possibly be used in a lamp suitable for paraffine oil. The residuum left in the retort when 80 per cent, of oil was drawn over was a hard brittle pitch, which can be obtained from the crude oil in the proportion of 73 grs. to the fluid ounce. This pitch when further examined gave 28 per cent, of hydro-carbon evolved at a high temperature, and 62 per cent, of a lustrous vesicular coke, which contains 777 per cent, of ferruginous ash. The general results of these experiments may be tabulated as follows : — One hundred parts of the crude oil, as obtained from the wells, having a specific gravity '962, gives— Distilled oil of specific gravity-874 ... ... ... ... ... 2 •893 10 •917 8 ■941 60 Solid bitumen ... ... ... ... ... ... ... • 6"1 Fixed carbon ... ... ... ... ... ... ... 124 Ash 1-5 1000 It may perhaps be considered premature to form an opinion as to the prospect of these wells from the result of the analyses of the small samples yet obtained, which, I understand, are only collected as drippings from the boring rods and pumps ; but it must be remembered that it is usual to strike the lightest oils first when boring, and it may be expected with more certainty if in this case the oil has been condensed in the rock from a state of vapour, that the lightest and most valuable oils should be met with nearest the surface. It, however, occasionally happens that petroleum obtained in one part of an oil-bearing district is much denser than in others, and sometimes even passes gradually into semi-solid bitumen, so that the occurrence of this heavy oil at Taranaki does not necessarily indicate the total absence of the finer oils, but only that the locality in which the borings have been made may not be the most favorable. A remarkable instance of this gradual change of the quality of the oil occurs at Baku, on the shores of the Caspian Sea, where the petroleum is obtained over a tract of" country twelve square miles in extent, the strata being a porous argillaceous sandstone, full of fossil shells of the tertiary period. The oil obtained from the centre of this district is very light and colorless, and accompanied by quantities of inflammable vapour; while towards the sides of the district it becomes darker iv color and more dense, and gradually passes into asphaltum. In concluding these remarks, I would remind explorers for oil wells in New Zealand that petroleum is to be found in nearly all parts of the world, and has been recognized and worked from time immemorial for illuminating purposes. The only novelty in connection with it in the present age is the discovery of large natural

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EOUND AT TAEANAKI.