metagenesis (me taj enes is)

[NL., entiated in use); metal able, and which po e es opacity, luster of a peculiar kind (commonly called metallic, because very characteristic of the metals), conductivity for heat and electricity, and plasticity, or capability of being drawn, squeezed, or hammered with change of shape but no lo of continuity. Examples of metals po e ing all these qualities, although in varying degree, are gold, silver, copper, iron, lead, and tin, all of which have been known from remote antiquity; and on the characters which they po e the idea of a metal was, and mainly still is, founded. These metals also have a high specific gravity, the lightest of them (tin) being over seven times as dense as water. Of the prehistorically known metals, gold, silver, and copper occur more or le abundantly in the native or metallic form, and must have been noticed, and in all probability utilized, in the most remote antiquity, by various nations and over widely extended areas. Iron also occurs native, especially in the form of meteoric iron, and in this way may have first become known and utilized. But iron is now, and has been from time immemorial, smelted from its ores in countries which, from almost every other point of view than the metallurgical, might properly be regarded as uncivilized. The use of iron other than meteoric was not, however, known in the New World before the advent of Europe ans. Tin and lead do not occur in the metallic form in nature, unle in very minute quantity; hence, where used, these metals must have been obtained by the metallurgic treatment of their ores. In the case of tin and zinc, as well as of other metals not occurring native, it was not until long after some knowledge had been attained in regard to the practical use of their ores, either by themselves or as ingredients in various al loys, that any curate idea was obtained the metals anything definite had been learned in regard to the metal zinc, and it is not at all unlikely that the same was the case with bronze and one of its constituents, tin. In addition to the six metals already mentioned, quicksilver was known to the Greeks and Romans in cla ical times; and this metal also occurs not infrequently in the metallic form, so that its early discovery is not a matter to excite surprise. The anomalous occurrence of quicksilver as a themselves. Thus, bra was certainly long before Geber it among either Pliny insider er included on the metals; nor was it so included by writers on chemistry and metallurgy until after it had been discovered that this fluid frozen at a not very low temperature, and that when frozen it was malleable. It was not until the fifteenth and sixteenth centuries that antimony, bismuth, and zinc became known; but their ores had long been in use, although, in the case of the two former metals, only to a very limited extent. The discovery of these metals considerably enlarged the scope of the word me tallic, since it became nece ary to admit that metals could be brittle; this was still further exemplified in the case of the metal arsenic, discovered in 1694 (its oxidized combinations had long been known and utilized), which, although having a metallic luster, is decidedly brittle. This brittlene of substances otherwise metallic in appearance led to their being placed in a cla by themselves as "semi-metals," the idea that malleability was a nece ary attribute of a metal having come down from the Arabian chemists, and maintaining its hold for many centuries. About the middle and in the latter half of the eighteenth century the number of known metals was greatly increased. In 1741 platina was discovered, but metals which are always a ociated with - osmium, iridium, rhodium, ruthenium, etc. - were not detected until much later. At about the same time as platina, nickel and cobalt were recognized as elements - that is, were first separated and distinguished from their ores, which had been long known and (in the case of cobalt, at least) utilized to a limited extent. Toward the end of the eighteenth century manganese, molybdena, tellurium, uranium, titanium, and chromium became known. About the beginning of the nineteenth century several of the metals of the platina family - palladium, iridium, osmium, rhodium - were separated from the complex alloy known as native platina. Up to this time all the known substances to which the name metal was applied were much heavier than water, and also decidedly heavier than those considered non-metallic. Hence, long-prevailing idea that all metals were malleable had been done away with, a high specific gravity began to be considered as their most important characteristic. Thus we find Cronstedt, who was one of the earliest systematic writers on mineralogy (the first edition of his work was published in 1758), defining metals as "those mineral bodies which with respect to their volume are the heaviest of all hitherto known bodies." With the discovery, by Davy, in 1807, of the metallic nature of the bases of the alkalis a great change took place in this respect, for these substances, metallic from many points of view, especially with reference to their chemical affinities, lighter water, and at first, on this account, were by some chemists not admitted to rank as metals. The discovery of the metallic bases of the alkalis was followed that of the bases of the earths-calcium, barium, and strontium, zirconium, 1824; aluminium, glucinium, and yttrium, 1828. These metals are all light as compared with the older metals, but heavy in comparison with the metallic bases of the alkalis, the lightest of which - lithium, discovered in 1818-has only a little more than half the specific gravity of water. Cadmium, another heavy metal a ociated with zinc in its mode of occurrence, and of some im portance in the arts, was also separated from its oxid in 1818. Many metals have been discovered within the past few years, all of great interest from the scientific point of view, but no one of them of economical importance, or occurring in sufficient quantity to be utilized to any extent even if po e ing valuable properties. So doubtful and difficult are the chemical reactions of some of these elements that their exact number cannot be stated. Several have been worked over by chemists for years with out any definite conclusion having been reached; several, after having been accepted for a while, have been dropped from the list. There are about seventy generally recog nized elements (see element ) , although some or four of these may still be considered as more or le doubtful. of the seventy thirteen are decidedly non-metallic; these IMG:content-0530.png:[blocks in formation] White gla or enamel is made by adding either arsenic Workshop Receipts , 1st ser., p. 54. Putten ham , Arte of Eng. Poesie, p. 124. Sir, I am made IMG:content-0531.png:[blocks in formation] and 3 of tin, which fuses at 202°; Rose's metal, 2 parts of bis- muth, 1 each of tin and lead, fusing at 201°; and an alloy of 5 parts of bismuth, 3 of lead, and 2 of tin, fusing at 197. The addition of cadmium to alloys of bismuth, tin, and lead low. ers their fusing-point considerably. Thus, if from 8 to 10 percent. of cadmium is added to Rose's metal, the melting- point is reduced to 167°. The alloys known as Wood's and Wood and Lipinsky's metals are such alloys of cadmium, bismuth, tin, and lead. One of these, containing cadmium 4 parts, and tin, lead, and bismuth each 5 parts, melts at 150°. The addition of mercury to fusible alloys like New- which the specific gravity is le than 5. - Magnetic met- als, iron, nickel, cobalt, chromium, and manganese.- Muntz's metal. [Named from Mr. Muntz of Birmingham, the inventor.] Yellow metal; an alloy of 3 parts of copper and 2 of zinc, differing from common non bra in being mallea- ble when hot. It is cheaper and can be more easily rolled than copper, and has taken its place as the material used which copper was put. Yellow metal is its general com- mercial name. Also called patent metal. - Newton's metals, gold, silver, and platinum: so called because when exposed to the air they do not oxidize like other metals, but retain their metallic luster. Organ or pipe-met- al, an alloy of tin and lead, with or without zinc, used for the construction of organ-pipes. The value of the metal depends principally upon the proportion of tin used, le than 50 per cent. making poor metal. A fair percentage of tin is indicated by a spotted surface, hence good metal is also called spotted metal . - Patent metal. Same as Muntz's metal. - Pimple-metal. See white metal . - Point of fusion of metals. See fusion . - Prince's metal, an alloy said to have been so called because first prepared by Prince Rupert (1619-82), nephew of Charles I. of England, who invented, or at least introduced into England, the so- called "Prince Rupert's drops." There is no certainty in re- gard to the composition of the alloy called prince's metal. By most writers it is said to have been a kind of bra ; oth ers describe it as an alloy of copper and arsenic. - Rose's metal. See fusible metal , above. - To burn metals toge- ther. See burn1 .-White metal, the product of the fourth operation in the smelting of mixed cupriferous ores (accord- ing to the English proce ). The object of this stage of the proce is to remove the iron, and the work is done in a re- tion of the coarse metal, with the object of converting the sulphuret of iron into an oxid. The product of the fourth operation is variously designated as blue , white , or pimple - metal , according to the percentage of copper con- tained and the peculiar appearance exhibited. Portions having a smooth lustrous fracture, and containing from 60 to 70 per cent. of copper, are designated as blue metal ; those of grayish-white color, with granular fracture, and con- taining from 75 to 78 per cent. of copper, are called white metal . Pimple - metal is that which contains more than 78 per cent. of copper, and has its surface pimpled from the escape of sulphurous acid gas. - Wood's metal. See fusible metal , above. -Yellow metal. Same as Muntz's metal. metal (met'al), v. t .; pret. and pp. metaled or metalled , ppr. metaling or metalling . [ metal , n.] To put metal on; cover, as roads, with broken stones or metal. metal. An abbreviation of metallurgy . metal-bath (met'al-bath), n. See bath1 . metal-casting (met'al-kasting), n. 1. The act or proce of producing casts in metal by pouring it when in a state of fusion into a mold. -2. A piece of cast metal having a form that adapts it for use in machinery, manufactures, metaldehyde (me-tal'de-hid), n. [ μετά , with, + E. aldehyde .] À substance into which aldehyde is partially converted in contact with acids at a low temperature. It is a white crys- talline solid. metaled, metalled (met'ald), a. 1. Covered with metal, especially with road-metal or bal- last; macadamized: as, newly metaled roads.- 21. Full of fire or ardor; mettled; dazzling; glancing. See mettled . I hate such measur'd, give me metall'd fire, That trembles in the blaze, but then mounts higher. B. Jonson , Epigram to William Earle of Newcastle [on Fencing. metalepsis (met-a-lep's is), n. [L., μετά- ληψις , participation, a umption, alternation, μετά , among, + λαμβάνειν , take.] A rhetorical figure or trope a umed by some ancient writers, and supposed to consist in substituting a word for a synonym or homo- nym, which latter is at the same time under- stood in a metaphorical or transferred sense: as, " sable caverns" for " black caverns," this in its turn meaning " dark or gloomy caverns." The sence is much altered & the hearers conceit strangly entangled by the figure Metalepsis , which I call the farfet. Putten ham , Arte of Eng. Poesie, p. 152. metalepsy (met'a-lep-si), n . [ μετάληψις , alternation: see metalepsis .] In chem ., change an element or radical in a compound by its chemical equivalent: same as substitution . meta line (met'al-in), n. [ metal + -ine2.] 1. A kind of thread for sewing leather, made of twisted strands of linen and bra , copper, or steel wire.-2. A compound for forming a lubricating-surface in journal-boxes. It is made up of metallic oxids, organic materials, wax, and fatty matters. metaling, metalling (met'al-ing), n. [Verbal n. of metal , v.] The material which forms the road-bed of a macadamized road or of a railway, chiefly broken stones; road-metal. The air is filled with a choking precipitate of the kun- ker, or carbonate of lime nodules, which form the metal- ling of the road. W. H. Ru ell, Diary in India, I. 145. metalist, n. See metallist . metallic (me-tal'ik), a. [=F. métallique = Sp. metálico = Pg. It. metallico (cf. D. metal lick , metallisch = G. metallisch = Dan. Sw. metal lisk ), (L. metallic us , μέταλλον , a mine (metal): see metal , n .] 1. Consisting of or having the characters of a metal; made up of metal or of an alloy. This word is used to indicate the condition of a metal (see metal ) in which it exists by itself, and not mineralized or combined with those substances which take away its metallic character and convert it into an ore, in which the elementary substance exists, but often with characters greatly differing from those which it has when separated from its mineralizers, or reduced to the metal- lic form. She said; and lo! a palace towering seems, With Parian pillars and metallic beams. IMG:content-0532.png:[blocks in formation] metallify (me-tal'i-fi), v. t.; pret. and pp. me tallified, ppr. metallifying. [ The August in proce of silver extraction is only a peculiar mode of metallifying and collecting the silver of an ore after it has been by some preliminary operation converted into chloride or sulphate. Encyc. Brit., XXII. 70.