Götterlehre oder mythologische Dichtungen

Moritz, Karl Philipp

Bibliografische Daten

Monografie

Persistenter Identifier:: 1503406532162

Titel:: Götterlehre oder mythologische Dichtungen

Autor:: Moritz, Karl Philipp

Verleger/Verlag:: Haas

Erscheinungsort:: Wien [u.a.]

Erscheinungsjahr:: 1807

Umfang:: 380 S.

Sprache:: deutsch

Strukturtyp:: Monografie

Standort:: Universitätsbibliothek Stuttgart

Signatur:: 1L 2406(2)

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Kapitel

Titel:: Die Wesen, welche das Band zwischen Göttern und Menschen knüpfen

Strukturtyp:: Kapitel

Kapitel

Titel:: Sylvan

Strukturtyp:: Kapitel

; . ” ari Formation of Moss Gold and Silver. 71 ee tte ties int tment P——— ee ee rb tt re eee res Methods by which Crystallisation may be produced, * differing considerably from the methods enumerated in the tr. By condensation from a state of vapour. am Bey I, hence the necessity for forming the 2. I'rom pi fusi The artificially prepared moss metals are produced by a 3 Pros Baek “S100: process of reduction, aided neither by vaporisation, solution, 4- By electrolysis. ; fusion, nor ele&rolysis, neither are they produced * spon- 5. By SD change. taneously,” but they are prepared by the aid of a heated 5.'By thermo-reduction. reagent, Hence I have for convenience ventured to form a special class, i.e., crystallisation by thermo-reduction. This matter is, of course, very closely connected with the ordinary metallurgical processes of reduction, but in such manufauring operations no effort is made to obtain the metal in the crystallised state; on the contrary, it is the practice to favour the conversion of the metal into the 'iquid state as speedily as possible. Although, perhaps, there may be no true analogy be- tween the two cases, still it would be very interesting to calculate the amount of force requisite to produce the crystals, supposing that they had been mechanically pulled out like wires through a draw-plate, or had been squeezed out through moulds sirsilar to lead tubing. I hope at some future date to be in a position to sup- slement the foregoing preliminary notes upon a question which is of great interest and importance in the chemical zeology of mineral veins and deposits, when the series of experiments at present in hand are somewhat nearer com- sletion. 1. Condensation of a substance from a state of vapour, —e.g., iodine, arsenic, water-vapour yielding snow and hoar-frost. 2. Crystallisation from Solution.—As when crystals of a salt are obtained by the evaporation of its solvent, and as when a solution of sulphur in carbon disulphide is allowed to evaporate spontaneously, beautiful crystals of sulphur are left. ] . Co. 3. On Solidification from a State of Fusion.—This is commonly seen when metals such as bismuth, antimony, and others are allowed to solidify slowly. Beautifully crystallised examples of such metals and of sulphur may he readily obtained in the following way :—Melt a consi- derable quantity of the substance in a crucible or ladle, and when a thin coat has formed over the surface by cooling, pierce the crust, and pour out the still fluid con. tents as quickly as possible. A large part of the metal or sulphur, as the case may be, will be left lining the inside of the crucible in the form of most beautiful groups of crystals with sharply-defined edges and angles, and not as the rounded, imperfe®, semi-fused-looking bodies that we might naturally expect when we consider the density and viscosity of the fluid in which they were formed and by which they were bathed. 4. Crystallisation by Electrolysis.—W hen solutions of the salts of the heavier metals are submitted to the a&ion of ele@ric currents they undergo decomposition, and the metal which is deposited at the negative pole is usually more or less crystallised. A current of low intensity, ceteris paribus, seems to favour the formation of well developed crystals. The reduction of a metallic solution by a more electro-positive element may probably be classed under this head, as stannic chloride by zinc, or silver nitrate by lead, and so on. 5. Spontaneous Crystallisation, as it is usually termed, —e. g., the gradual passage of amorphous plastic sulphur into the crystalline state, also the similar change under- gone by barley-sugar. Many well-known chemical preci. pitates apparently undergo spontaneously a similar change. Again, the gradual conversion of tough fibrous wrought- iron into hard brittle iron with short grain, by repeated concussion and vibration, seems to be a variety of crys- tallisation ; certainly a great molecular change has taken place—but this matter requires further investigation. Then we have the passage of blocks of tin, which had been exposed to intense cold, from the malleable and non. crystalline to a fibro-crystalline and brittle state; in fa@ so brittle does the tin become that it more or less com: pletely falls to powder. The devitrification of glass may also be here mentioned. 6. Crystallisation hy Thermo-reduction.—I think that we may safely regard the forms exhibited by the artificially produced moss metals as varieties of crystalline forms, and with as much reason as the mineralogist assigns a place for the similar natural forms amongst crystals ; the arborescent and other group forms assumed by native metals can be traced from normal and primary forms, such as of the octohedron and rhombic dodecahedron through various’ degrees of elongation and attenuation until we arrive at the filiform and capillary threads, a number of which aggregated together give the velvet or plush-like mass of moss copper or other metal, Moreover, some portions of the gold reduced from the mispickel showed branching and arborescent groups which had all the ap- pearance of elongated dodecahedra placed end to end, in no way differing from natural specimens except in minute. ness and perhaps greater brilliancy of lustre. But these crystals have been produced by a process PROCEEDINGS OF SOCIETIES. NEWCASTLE-UPON-TYNL CHEMICAL SOCIETY. General Meeting, December 21st, 1876. The PRESIDENT in the Chair. T'HE following notes, descriptive of some of the apparatus exhibited, were read :— “ Fletcher's Improved Aspirator and Blower,” by J. W. Swan. This is a modification of the old Sprengel pump, from which it differs in some most important points. It will give an average duty as a blower of at least double. It will work with a fall of water so small as to be totally 1seless for the old form. The water inlet is arranged so as to throw the water icross the descending tube in compact masses, which act 1s pistons from the moment they enter the tube, and if the air and water are examined as they descend they will be found quite separate and distinct from each other. In the old Sprengel pump, when examined in the same way, the water wili be found to form a thick lining to the tube, with a free column of air in the centre, and in the whole length of the tube a large quantity of water can be seen running down the sides, doing absolutely no work. When a descending tube with a fall of 7 inches is used, it will bear immersion until the water overflow is only one inch below the inlet, and will still deliver air 6 inches below the overflow level. No greater test of the effici- ency of this part ef the apparatus can be conceived than the fac that a fall of water of three-fourths of in inch will pump air steadily into a tube of five-six- .eenths inch bore, or nearly half the diameter of the total all. Whatever the speed or fall used, the clear definition setween the water pistons and the. air is equally distinct ; and so far as | have tested the arrangement the efficiency as a blower or aspirator is in dire proportion to the {ifference in level between the inlet and outlet pipes. The air and water at the bottom of the descending tube are delivered against the side of the air chamber, down which the water runs quickly, thus preventing to a great sxtent the presence of water vapour in the air. As an additional safeguard the air chamber is made very narrow wd tall, and at the air outlet near the top is also placed

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