with iodid of ethyl yields, among other products, butyric ether from which the acid may easily be obtained. The reaction by which butyric ether

Na

CCH

+NaL. By the action of iodid of methyl upon disodium

acetic ether the authors obtained an acid also identical or isomeric with

+2Nal. The authors leave it for the present undecided whether acids having the formula of butyric acid, obtained by different processes, are identical or only isomeric. By the action of iodid of ethyl upon disodiumacetic ether the authors obtained an ether isomeric or identical with capronic ether. Chemists will await with impatience the completion of this investigation, promising, as it does, to lead to results of the greatest theoretical interest.-Ann. der Chemie und Pharm., lix, p. 217.

W. G.

8. On the heat of friction; by Prof. JOSIAH P. CooкE, Jr. (Proc. of the Amer. Acad. of Arts and Sci., vi, April, 1865).- An accident to one of the large turbine wheels employed by the Merrimack Manufacturing Corporation of Lowell has furnished a most remarkable illustra tion of the modern mechanical theory of heat, and through the kindness of Mr. Isaac Hinckley, the accomplished agent of the Corporation, I have the pleasure of bringing the facts to the notice of the Academy. I cannot do better than to begin by reading Mr. Hinckley's own statement, in a letter addressed to me, dated December 30th, 1864. The specimens referred to in the letter I have placed on the table for the inspection of the Academy.

"In accordance with your request, I herewith send you five pieces of metal, once portions of one of our turbines. I have placed these pieces in the box in the same relative position which they occupied when they made a part of the turbine. To make my statement clear to you, I would refer to Plate I, of Mr. Francis's admirable work, Lowell Hydraulic Experiments,' which you will find in the College Library. Our turbines are similar to the Tremont turbines therein shown.

"The turbine of which these pieces were a part is one of 250 H. P., under a fall of 32 feet, using 75 cub. ft. of water per second. The wheel is of 58 inches diameter, with depth of float of 6 inches, and a velocity of 144 revolutions per minute. Its position is horizontal, and at a level of 3 feet below the surface of Merrimack River at its ordinary stage. It is mounted upon a vertical wrought iron shaft 25 feet long

and 6 inches diameter at smallest place. This shaft is fitted at its upper end with a series of disks, by means of which it is supported in its box, which is again supported by a massive cast-iron frame. This frame supports the entire weight of the wheel and shaft. The shaft at its lower end is bored in the line of its axis to a depth of 5 inches to receive a steel pin of 174 inches in length and 24 inches in diameter, and which projects from the shaft 12 inches. The steady-pin has no function to perform other than that of restraining the shaft from lateral aberration. It is free to revolve in a box made of three pieces of casehardened iron, so placed in a cast-iron frame as to allow free play to the steady-pin and the free access of water to it. Each of these three pieces composing this box is kept up to its place by following-screws working in the cast-iron frame which is bolted to the stone floor of the turbine pit. In the Tremont turbine this floor is of wood, and in Plate I, the steady-pin is marked 'I.'

"The pieces sent are marked Nos. 1 to 5. No. 1 is the portion of the steady-pin which was nearest the shaft; No. 2, the other extremity of the same pin; Nos. 3, 4, 5, the three pieces of case-hardened iron forming the box, with portions of the steady-pin attached. You will at once perceive that this steel has been partially fused, and can thus account for its attachment to the iron.

“The facts are, that on noticing some irregularities of motion on the part of the wheel, it was stopped, and the water pumped from the pit until the floor was bare. Inspection showed that the following-screws had not done their duty uniformly; and the three pieces, Nos. 3, 4, 5, no longer preserved their proper relative positions, nor allowed free play to the steady-pin. The consequence was, an amount of friction causing heat sufficient to fuse steel, although the latter was immersed three feet deep in a raceway ten feet wide, through which was passing seventy-five cubic feet of water per second.

"A similar accident happened thrice to our turbines, which are now, however, safely guarded against such mishaps."

There are two points in connection with these facts to which I wish especially to call attention. In the first place, the weight of the wheel did not rest upon the surfaces of friction. The three pieces of casehardened iron in their displaced position acted simply as a brake upon the revolving shaft, so that the heat must have resulted wholly from the destruction of mechanical motion. The immense moving power of the wheel, instead of being directed wholly into its appropriate channel, was in part transformed into that mode of atomic motion called heat. In the second place, the temperature attained was at least the weldingpoint of iron, and this, too, although the heated metal was immersed in a stream of flowing water. It is undoubtedly true, that the spheroidal condition of the water would greatly retard the loss of heat, but still the loss must have been exceedingly rapid. Now the loss, even at the highest temperature attained, must have been fully supplied by the heat generated during the same time; and this must, therefore, have been evolved with equal rapidity at the surfaces of friction. No change in the molecular condition of the iron, and no abrasion of the metal, is at all sufficient to account for this continuous, prolonged, and immensely

rapid evolution of heat, and the facts force upon us the conclusion, that the destruction of mechanical motion is the one and only efficient cause. Moreover, if we admit the generally received principle of mechanics, that motion cannot be annihilated, the conclusion that heat is a mode of motion is equally irresistible. Lastly, it is evident that the facts here stated perfectly accord with the well-known experiments of Rumford and Davy; only since the moving power of the Merrimack turbine is so much greater than that employed by these distinguished experimentalists, the results which I have had the pleasure of exhibiting are more striking and conclusive than any which have been previously obtained.

9. On the Magnetic effects of the Aurora. (In a letter to the editors from Mr. MOSES G. FARMER, dated Salem, Mass., Oct. 2, 1865.)-In the Boston Evening Transcript of Aug. 4th, 1865, was published an account of some observations made by Mr. Geo. F. Milliken, manager of the Boston office of the American Telegraph Company lines, upon the magnetic effects of the aurora.

Mr. Milliken says that in one case, the deflection of the needle of his galvanometer reached 78°, and remained at that deviation for about two minutes. I had the curiosity to insert my Gaugain galvanometer into this same circuit, in order to ascertain the actual value of this deflection. I found it to correspond to the evolution of of a cubic centimeter of mixed oxygen and hydrogen gases per minute, equal to the decomposition of 3 of a grain of water 339 per hour.

=

Let us assume for the unit of strength of current the evolutions of one cubic centimeter of mixed gases per minute, and let S signify strength of current measured according to this unit. Let the unit of resistance be that offered by one foot of a round wire, one twentieth of an inch in diameter, and made of pure copper, (nearly 130000 footseconds,) and let R denote units of resistance. Denote units of electromotive force by E, then will E=RS. Furthermore, denote units of electrical energy by E, then will E-RS2 ES express the relations between electrical energy and its corresponding resistance, electromotive force and strength of current. The mechanical value (denoted by M) of this unit of electrical energy is equal to robo foot-lbs. per minute, or M0019 E.

1914

1000000

The measured resistance of the line from Boston to Springfield, including the relays in circuit, was found to be equal to 515970 of our units; hence the electrical energy per minute, exerted by the aurora upon the line while the needle stood at 78°, was E=515970X(683)2= 241241; and its equivalent mechanical value was M=0019×241241= 46.173 foot-lbs. per minute.

This wire is of iron, and is one hundred miles in length; it was originally of the wire known as No. 9, hence its volume could not exceed (148) 2×5280×12×100=108925 cubic inches,—63·03 cubic feet. Therefore the mechanical energy per cubic foot of the wire=

7.32 foot-lbs. per minute.

461.73

63.03

=

If we suppose the auroral energy to be equally active at all points of space where its presence was evident, we shall find it to amount to

528037.321077489008640 foot-lbs. or more than 32000000, thirty-two millions) of horse-power per cubic mile of space. When we remember that the effects of this aurora, or magnetic storm, were felt in England as noticed by Mr. Airy, and probably upon the Atlantic cable which was then being laid, we can, in some degree, realize what mighty energies may be at play around us, and yet their effects be as harmless as the silvery moonbeams.

II. MINERALOGY AND GEOLOGY.

1. Pachnolite, a new mineral.-In searching for crystallized cryolite, Ksor has discovered an interesting mineral which occurs in druses and on the lines of cleavage of partially decomposed or weathered cryolite. The mineral is found in two varieties. In one case the crystals rest on the cryolite, and occur in right-angled parallelopipedons with three unequal cleavages parallel to the basal and lateral planes of the crystal. The other variety occurs in druses formed by the solution and removal of the cryolite. These druses are curiously divided by rows of crystals of the new mineral placed end to end, forming little comb-shaped partitions, the center of each partition being in the line of cleavage of the original cryolite. The crystals are lustrous, transparent and colorless, and from their resemblance to hoar-frost, Knop has named the new species Pachnolite from πάκνη, frost.

Heated gently in the closed tube, the mineral gives off neutral water, at a higher temperature the water has an acid reaction, heated rapidly it is decomposed with crackling and the formation of a white cloud which condenses on the walls of the tube. It is decomposed by sulphuric acid with evolution of fluohydric acid. Chemical composition :

3

from which Knop draws the formula 3(Ca, Na,) Fl+Al2Fl ̧+2Ħ= FI 51.12, Al 12-29, Na 12·38, Ca 16·14, H 8.07=100.

The crystalline form of pachnolite as determined by Knop and v. Rath is trimetric. The crystals occur in simple rhombic prisms sometimes with octahedral planes with pyramidal terminations, and occasionally the pyramidal planes have a stair-like form growing smaller towards the end of the crystal.-Annalen der Chemie und Pharmacie, vol. cxxvii, p. 61. [Dr. G. HAGEMANN, chemist to the Alkali Works at Natrona, Pennsylvania, has in a recent letter communicated to us the results of his investigations of this species, confirming the observations of Knop as to its crystalline form and chemical composition. Dr. Hagemann's analysis gives:

It is interesting in this connection to note that cryolite is now imported from Greenland by the cargo to Natrona for the purpose of manufacturing soda ash, alumina salts and other products mentioned in volume xxxv, p. 285.]

G. J. B.

2. On Chrysolite with Chromic Iron in Pennsylvania; by Dr. F. A. GENTH. From a letter to Prof. Dana, dated Philadelphia, Dec. 10, 1865. -It is about one year ago, since I wrote Prof. Brush of a very interesting discovery which Prof. Booth made, of a large crystal of chrysolite from the great (or once great) chrome mine, called Wood's mine, in Lancaster Co., Pa. The occurrence is the more interesting to me, since, in a certain degree, it confirms my views as to the parent rock of the serpentine and tale of the chrome region. I may add that I have also received chrysolite, associated with hornblende and magnetic iron, from near Media, Delaware Co., Pa., at which locality occur the best crystals of chromic iron.

3. Crystallized Gold in California.-Prof. W. P. Blake states that a mass of gold which is for the most part a congeries of imperfect crystals, has been found 7 miles from Georgetown, El Dorado Co., California, which weighs 201 oz., and is valued at $4,000. The mass is now in New York city.

He also has a California crystal of an octahedral form, which if perfect would measure 2 inches on a side.—In a letter to Prof. Dana.

4. On an Asphalt vein in Wood Co., Western Virginia; by J. P. LESLEY. (Proc. Amer. Phil. Soc., ix, 183, 1863.)-This vein, situated about 20 miles (in an air line) south of Parkersburg, cuts vertically through rocks that are nearly horizontal and have a strike of S. 78° W., while the strike of the county is S. 35°-40° W. It is a vein of a solid bitumen-like substance rather than a coal bed. It resembles the glossiest, fattest caking coals; much of it breaks up into small prisms, and none consists of layers. In an assay made by Mr. B. S. Lyman of Philadelphia, in which the amount of hydrocarbon soluble in benzole was found to be about one-half of the whole, the volatile matter, according to the mean of two assays was 47.11, and of ash 173. The substance filling the vein is beyond question, Mr. Lesley observes, a product of the gradual oxydation of coal oil that once filled the open fissure.

5. Descriptions of Fossils of the Marshall Group of Michigan, and its supposed equivalent in other States; by Prof. A. WINCHELL.-Prof. Winchell's extensive investigations among the fossils of the sandstones lying between the Devonian Black Shale of the interior basin (equivalent of the Genesee shale of New York), including the beds called the Waverly sandstone in Ohio, and those of the rocks of which his Marshall Group in lower Michigan consists have led him to suggest, if not believe, that these beds are not equivalents, even in part, of the Chemung beds of New York, but rather of certain conglomerates in western New York which have been referred to the inferior Carboniferous. His former identifications of fossils with Chemung species are all abandoned, while an identity with four of the few species of the conglomerate alluded to (found only 4 miles north of Panama, Chautauque Co.) is proved. These four species are Euomphalus depressus Hall (Straparollus Ammon White), Cypricardia contracta Hall (Edmondia? bicarinata Winchell), Edmondia aquimarginalis Winchell, and Allorisma Hannibalensis Shumard. the facts, he says, "it does not seem unreasonable to suspect a continuity between the more western beds and the supposed Carboniferous conglomerate," at least until observation shall have demonstrated that the Mar

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