or ought never to be present at all, may be ascertained by the equation

co-lat.-obliquity of ecliptic=g',

for the first; and by the equation

co-lat. +obliquity of ecliptic=g';

for the second. Putting D=9000, as in the March number of this Journal, g=26°; and the equations foregoing will give the latitude 40° 32′ as the limit of perpetual apparition of the light, and 87° 28′ as that of its perpetual occultation.

By assuming, in the triangle ZSQ, 8=18°, and the position of Q on the circle H'R', we shall find that the visibility of the light as an arch of which the extremity is beneath the horizon when the sun is 18° depressed, will be limited to places between the latitudes at which the maximum inclination of the ecliptic to the horizon is not less than 26° on the one hand, and the minimum not greater than 28° 34' on the other; and the season of its greatest conspicuousness at any given hour, or at any given depression of the sun, may be found by putting I=28° 34' in the equation given in the note on p. 231 of the last number of the Journal,* viz.

cos I=sin L cos 0-cos L sin O sin A,

in which I is inclination of ecliptic to horizon, L latitude of observation, O obliquity of ecliptic, and A right ascension of the culminating point of the ecliptic. The value of A being found, the R. A. of the sun follows immediately, in case the hour angle is given; and is deduced without difficulty from the depression, if that is the given quantity.

Thus at Oxford, lat. 34° 30', the arch could never be seen at the close of twilight, unless the cusp were at the same time visible; but at New Haven, about the time of the autumnal equinox, the axis of the light ought apparently to rise two or three degrees above the horizon at the same hour, though it would be impossible to see the extremity. Some further arguments unfavorable to the hypothesis which ascribes the zodiacal light to a luminous ring encircling the earth might be drawn from the considerations presented in this letter; but after what has been said, it is, perhaps, unnecessary to add more.

University of Mississippi, Oxford, March 15, 1856.

In case the maximum inclination of ecliptic to the horizon is not so great as 28° 34', substitute that maximum itself for I.

SECOND SERIES, Vol. XXI, No. 63, May, 1856.

51

ART. XLV. On the Presence of Vivianite in Human Bones; by J. NICKLES.

In the cemetery at Eumont, a village in the Department of La Meurthe, the earth of which is very ferruginous, there has been found among the bones, the accumulation of several centuries, two arm bones of a female, a cubitus and a radius, having a deep bluish green color. One of these bones having been broken through curiosity, it was discovered that the color was general through its whole thickness. This bone having been sent me, I have observed the following facts.

The color was decidedly greenish; but as the osseous paste was yellow, it was evident that the coloring matter was blue. By dissolving a fragment in chlorhydric acid and supersaturating with ammonia, a white precipitate of phosphate of lime slightly bluish in tinge was obtained, showing that the color was not due to copper. Reagents indicated the presence of iron; but as the bones all contained iron, it was not at first easy to ascertain whether this metal was in the coloring matter, although it much resembled phosphate of iron. My subsequent investigations proved that this last was true. On examining the medullary cavity with a lens, I found among the sinuosities left by the hardened marrow, brilliant points which were distinctly crystalline. With a microscope, they were found to be rhomboidal prisms apparently oblique, some of them surmounted with a horizontal prism, and others with octahedral planes having the terminal planes applied to the two extremities of the macrodiagonal. They were too small for measurement. But by chemical methods, they were found to have all the characters of phosphate of iron. Calcined with bicarbonate of soda, the acid and oxyd were readily separated; and on treating the calcined product with distilled water, I obtained a residue of oxyd of iron and an alkaline solution, which on neutralizing it, afforded an abundant precipitate with ammonia, chlorhydrate of ammonia and sulphate of magnesia. This was therefore phosphoric acid, and the substance a crystalline phosphate of iron, which can be only Vivianite. The presence of the bones in the ferruginous water explains its formation, the bones affording the phosphoric acid from the phosphate of lime.

This fact recalls to mind an observation made some years since by Schlossberger, who detected in the stomach of an ostrich that had died suddenly, two nails surrounded with an unctuous material of a bluish color, which coloring matter the author found to consist of a phosphate of iron, having the composition of Vivianite.

The bones mentioned above were in a perfect state of preservation, and afforded a skeleton of gelatine when treated with

chlorhydric acid, proving that gelatine does not resist the absorption of the ferruginous compound. We know nothing as to their exact age. The presence of gelatine is not a matter of surprise, as is shown by the discovery of it in the fossil horn of an Aurochs (Bos urus) by Braconnot,* and the antediluvian soup of Cuvier. They probably date back hardly two centuries. Whatever the time, they illustrate the interesting fact of the modern origin of Vivianite and the conditions favoring it.

ART. XLVI.-Correspondence of M. Jerome Nicklès, dated Paris, March 2, 1856.

Academy of Sciences.-Distribution of Prizes.-The annual session of the Academy of Sciences was held on the 28th of January, when M. Flourens pronounced an historical eulogium on the distinguished geologist, von Buch.

Notwithstanding the fine discoveries made this year in the departments of physics and chemistry, no prize has been given to the indefatigable workers who have contributed to the progress of these sciences.

The prize of mechanics was given to Captain Boileau, Professor at the School of Artillery of Metz, on account of his researches in hydraulics" a science which, in spite of all the remarkable works undertaken at different times in France, England and the United States, has not yet attained to the perfection and certainty required for precise calculations in the varied cases brought before the engineer." The Academy, in bestowing the prize, includes also a recognition of the delicate apparatus contrived by M. Boileau for studying the flow of water in open channels and over dams, as well as his experimental researches on the sawing of wood, through which the author has devised new sawing machines.

A prize extraordinary in statistics was conferred on M. Le Play, the late commissary general of the Universal Exposition, for his work entitled "Les Ouvriers Européens ;" another to M. Vicat, for his statistical researches on calcareous hydraulic cements. M. Vicat in his work has aimed to point out the mineralogical resources of France, with special reference to materials for constructors; the work embraces references to the minerals found in 76 of the Departments.

Among the prizes relating to the arts that are injurious to health, one of 2500 fr. was given to M. Duméry for a contrivance for consuming the smoke of chimneys, which has worked with complete success in a series of comparative experiments under the inspection of the learned mechanician, M. Combes, Member of the Commission.

M. Duméry, in place of throwing in the fresh coal by the door of the furnace upon the burning combustible, as in ordinary fires, causes it to enter below by means of stoking bars worked with the hand in a kind of recurved funnel, with open sides, and extending to the grating on that side. This method was long ago suggested by Franklin; but

* Journal de Physique, August, 1806.

the arrangements here adopted are peculiar to this inventor and attain perfectly the end proposed.

The Commission has decreed three other prizes of less importance. As usual the Commission in Medicine and Surgery has been just and generous in its prizes. It has not confined its attention to medical and surgical works, but has given prizes as in the last year, even to researches in chemistry and physics where they have some relations to medical science. A prize was thus bestowed upon Dr. Hannover of Copenhagen for his work on the Eye; another to Dr. Lehmann of Saxony for his Treatise on Physiological Chemistry, published in German at Leipsic, and which has just been strangely disfigured by a French edition that has of the work only its title.

Aluminium and Silicium.-M. Wöhler and M. Deville have both devised easy processes for obtaining pure silicium. Wöhler uses fluosilicate of potash, 3K F1+2Si F13 in excess, which he fuses with the aluminium in a Hessian crucible. After cooling, the mass is found to contain a crystalline material, an alloy of silicium and aluminium, before observed by Deville, which after treating with chlorhydric acid deposits silicium in a graphite-like state.

It con

Deville's process affords the silicium in a crystalline state. sists in heating the aluminium in a porcelain tube traversed by a current of hydrogen saturated with vapor of chlorid of silicium: the treatment is continued until there is no disengagement of vapors of chlorid of aluminium. The crystallized silicium contains some impurities which are removed on treating it successively with nitro-muriatic acid, boiling fluohydric acid, and melted bisulphate of soda. As long as the operation is not complete, there are found small globules of siliciuret of aluminium, Si A12. The fluorid of silicium used in place of the chlorid would equally furnish silicium; at the same time, a new compound of fluorid of aluminium, F13A12, is formed, crystallized in fine cubes and unattacked by almost all reagents.

Silicium crystallizes in octahedrons and tetrahedrons, and conforms therefore to the rule which I established in 1851,* that simple bodies crystallize generally either in the monometric or rhombohedral system.

By the same process, Deville has prepared crystallized boron as well as crystallized carbon with a hexagonal base, zirconium, and titanium. We will recur to the subject at another time, and then describe the new apparatus, such as tubes of carbon, &c., used in these operations, as executed at the Normal School, which institution, has, through the University, extended means of research.

Artesian wells.-An artesian well is in progress in the Bois de Boulogne a meter in diameter, and capable of supplying 10,000 cubic meters of water per day. The engineer who has it in charge, M. Kind, has so perfected the process, that he offers to go to a depth of 720 meters, and even to descend to a depth of 2000 meters. The boring was commenced on the 2nd of August with a diameter of 12 meters. Descending through marl and soft sandstone, the rate was five meters a day; in a bed of sand it was two to three meters; by the 1st of May the depth will reach 700 meters.

* Comptes Rend., xxxii, 853.

screws.

The process employed by M. Kind is an improvement on the Chinese method of percussion. A cylindrical rod of wood, is made of sticks of young pines, ten meters in length, united by sockets of iron fitted with The quantity of iron added to each piece is just that required to counterbalance the water. As water is encountered at a depth of 20 or 30 meters, and it continues to fill the hole, it results that the shaft, which, whatever its length, is thus made to equal the water in weight, has relatively almost no weight, so that it is moved by a small force; and being made of pieces of wood put end to end, its strength is very great. The extremity of this rod carries a grapple at bottom which opens as it descends, and then closes when it is raised by means of a parallelogram connected at its angles with two cords, which cords reach up to the orifice of the well, where they may be managed with the hand or by means of machinery. At the bottom of the well, there rests a drill weighing 1800 kilograms, quite similar in form to that used for pounding and drilling rocks, but armed below with seven teeth of cast steel twenty-five centimeters long, fitted to drive into the bed of rock and break or abrade it. The drill has a shank above by which it may be seized and lifted.

The mode of operating is as follows:-With a steam-engine of twenty-four horse power, working a horizontal balance beam, the rod of wood is let down. The grapple at its bottom closes, seizing the handle of the drill; it then rises, lifting the drill to a height of some meters above the bottom; the grapple then opens, and lets the drill fall; thus the drill is raised twenty times a minute. After working in this way twelve hours, the entire rod is raised along with the drill, which is done with great rapidity; the sticks of pine are taken apart in less than a quarter of an hour. They are then refitted, and the drill is replaced by a bucket having a valve below which is opened and closed also by the aid of the cords and the grapple; the bucket opens below, and being pushed by the piston, penetrates into the pasty mass and fills, after which the valve is closed, and the whole is drawn up, and the drill again sent down.

As it traverses different strata, specimens are taken, and thus a true geological section of the basin of Paris is obtained. A steam engine of thirty horse power is sufficient for all the work, and the number of workmen required is only six, costing each day 49 francs. The teeth of the borer are rapidly worn in quartz; they lose nearly two centimeters in two hours work. The mean expense of boring is per meter 54:39 fr.

Electric clock.-The city of Marseilles has undertaken to establish a complete system of electric clocks. One hundred clocks will be set up by the 1st of May. The arrangements require the laying of 40,000 meters of conducting wire. The clocks will be placed in the street gas lamps, so that the hour may be read at night as well as by day. The whole will cost only 22,000 francs, and the care and supply of them per year 2000 francs.

Chlorimetry. The anomalies presented at times in the process of treating with hypochlorite of lime (commonly called chlorid of lime) the standard test liquors of Gay Lussac, have just been explained by MM. Fordos and Gelis. A normal solution of the hypochlorite having,