CAMPHORIC ACID and SOME of ITS COMBINATIONS. by Robgrt FAIRTHORNE~ ESQ

142 Educational aperture, and 30 inches tbcal length, provided with a spectroscope of 5 glass prisms of 45 ° ; the spectroscope having an aperture of 2{ inches, and 17 inches focal length. The whole apparatus is mounted equatorially. The forms of the protuberances as seen by merely opening the slit, and looking at them through the c line (which appears then like a chink through which one looks out upon sunset sky), are very beautiful and fantastic, closely analogous to the light cirrus clouds of a spring or winter day, and varying nearly as fast. An hour sometimes almost wholly changes one. There are commonly four or five of them on the edge of the sun's disc at once. Usually, the chromosphere is found all around the sun with an average depth of from 15 to 30 seconds. To-day (July 19), a place was observed where the chromosphere was hardly perceptible ; it was not more than 5 seconds deep, and very Faint at that. Its position was on the south-cast edge of the disc, 128 ° from the north point, very near a spot of considerable size, which had only advanced a few minutes of arc upon the limb. May not this deficiency in the chromosphere indi- cate the precise position of a spot just coming round the limb ? Dartmouth College, July 19, 1869. CAMPHORIC ACID AND SOME OF ITS COMBINATIONS. BY ROBgRT FAIRTHORNE~ ESQ. NOT having been able to find any full description either of camphorie acid or its salts, I thought that perhaps others might have met with a similar disappointment and that the following com- munication would not be out of place in this Journal. By repeated distillation of camphor with nitric acid, that hydro- carbon is converted into eamphoric acid by absorption of six equivalents of oxygen, two of which appear to unite with two atoms of hydrogen, differing therefore from camphor, not only by the addition of the oxygen, but by two equivalents of the.hydrogen being abstracted. The composition of camphor being C20 H16 O2, that of camphoric acid is C20 H14 O6 + 2 H O. The combinations of this acid with the alkaline or metallic oxides are peculiar, and possess considerable beauty of form. I shall strive, however, to describe the appearance of the acid first. Camplwric Acid (~n(l .s'ome (!/' its Comhlnatlo~,.s. 145 The crystals from the nitric acid solution generally arrange themselves in shining, white, transparent tufts, having a hemispheroidal shape, the fiat surfaces of which float on the top of the nitric acid solution, wl~ilst prismatic crystals radiate downwards from central points in the disks. A still stranger form of crystallization is som'etimes produced from its solution in the same acid, for which I have been at a loss to account. It takes the form of minute opaque, white, leaf-like crystals, have a close resemblance to elaborately ca~ved ivory, each crystal being about the eighth of an inch long and about the twenty-fourth of an inch wide across the centre, and of an ovate form. From its alcoholic solution it solidifies in stellular transparent crystals. As obtained from its ethereal solution it is found not only as just described, but in long prisms also, having terminations which have somewhat of a feathery appearance. It dissolves freely in alcohol and ether but is insoluble in ben- zine a~d chloroform. It is soluble to a moderate extent in water above 150 ° F., and to a small extent in cold water. It combines readily with ammonia and the other alkalies. The ammonia salt crystallizes in silky star-like crystals, having a peculiar appearance. The aqueous solution of this salt reacts in the following manner with the articles hereafter named. With solution, of the sesqui- oxide of iron a light brown precipitate with a reddish hue is thrown down. It might almost be described as of a flesh color. The same result follows when mixed with the solution of the sesquisulphate. When added to the solutions of the proto-salts of iron no precipitation occurs. Mixed with the solutions of the sulphate of copper, a bright green precipitate is thrown down. Even with a solution containing so small a quantity of the sulphate as one grain in the pint, a decidedly marked color is produced, after allowing the mixture to stand for a few minutes. This color is so peculiar that I would propose it as a test for copper. With solutions of salts of lead a dense white precipitate is formed. With solutions of salts of mercury a similar precipitate is formed, and with the following solutions no precipitation is apparent, namely, with that of sulphate of zinc, of sulphate of morphia, of sulphate of I44 uEducational. quinine, of sulphate of cinchonia, of sulphate of magnesia. Neither is any produced with lime water. it appears curious that the transparency of solution of nitrate of silver is not disturbed by the addition of the camphorie acid or of the camphorate, as most acids of a vegetable origin produce dense precipitates with 'that salt. Philadelphia, July 9, 1869. New Oxygen Process.--Oxygen procured cheaply and easily, is, as we have often said, a very desirable thing. The numerous applications that could be made of it are £o evident that we need not stop to mention them, but we lay before our readers yet another plan, and this time an ingenious one, tbr obtaining it. The mineral sources of oxygen being comparatively expensive. MM. Montmag- non and Delaire have betaken themselves to that cheap reservoir, our atmosphere, and have further availed themselves of the discri- minative action of wood charcoal and water, or certain saline solutions. We give here, it must be understood, the figures of the authors named, without checking them by a reference to the figures of Dr. Augus Smith, who has made most careful experiments on the absorptive action of charcoal. According, then, to our authors, 100 litres of fresh wood charcoal will, when exposed to atmospheric air, occlude 925 litres of oxygen, but only 705 litres of nitrogen. Now, it would appear that when the charcoal so saturated with gas is thoroughly saturated with water, there will be expelled 650 litres of nitrogen, but only 350 litres of oxygen. Thus we have now left in the pores of the charcoal 575 litres of oxygen, and only 45 litres of nitrogen, that is, oxygen practically pure for industrial purposes. To extract the gases, the authors employ a pump, and they tell us that if again exposed to charcoal, the oxygen will be obtained almost pure. There can be no doubt of it. They give no account of the cost of oxygen ; but it is clear that it will be represented chiefly by the cost of the machinery and cost of working it.--Mec. Mag. Athenian Railroad, between Athens and the Peir~eens is nearly completed, and will probably be opened for traffic early in the present month. .

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