1827.] 



Varieties. 



95 



minute quantities as enter into the elements 

 of this calculation. 



Method of Softening Cast-Iron. A way 

 has lately been discovered of rendering cast- 

 iron soft and malleable ; it consists in plac- 

 ing it in a case or pot along with and sur- 

 rounded by a soft red ore found in Cum- 

 berland and other parts of England, which 

 pot is then placed in a common oven built 

 with fire-bricks, and without a chimney, 

 where they are heated with 'coal or coke 

 placed upon a fire-grate. The doors of the 

 oven being closed, and but a slight draft of 

 air permitted under the grate, a regular 

 heat is kept up for one or two weeks, ac- 

 cording to the thickness and weight of the 

 castings. The pots are then withdrawn, 

 and suffered to cool, and by this operation 

 the hardest cast metal is rendered so soft 

 and malleable that it may be welded toge- 

 ther, or, when in a cold state, bent into 

 almost any shape by a hammer or vice. 

 Newton's Journal 



New Alloy of Metal. Several alloys have 

 been proposed as substitutes for brass, the 

 very rapid corrosion of which renders it 

 unfit for the construction of valuable instru- 

 ments. A German proposed, some time 

 since, a combination of copper and plati- 

 num ; but without stating the proportions, 

 which we believe vary from one to two parts 

 of platinum to three of copper. It is ra- 

 ther singular, that even in the present ad- 

 vanced state of chemical analysis, the exact 

 proportions of the materials which enter 

 into the composition of tutenach cannot be 

 assigned, although it seems probable that 

 few substances are better calculated to re- 

 pay the discovery. 



Indian Diamonds. From some researches 

 by Mr. Voysey, published in the last vo- 

 lume of the Asiatic Researches, it is ascer- 

 tained that the matrix of the diamonds 

 produced in Southern India, is the sand- 

 stone breccia, of the "clay-slate forma- 

 tion" that those found in alluvial soil are 

 produced from the debris of the above rock, 

 and have been brought thither by some 

 torrent or deluge, which could alone have 

 transported such large masses and pebbles 

 from the parent rock, and that no modern 

 or traditional inundation has reached to 

 such an extent that the diamonds found 

 at present in the beds of the rivers are 

 washed down by the annual rains. It will 

 be an interesting point to ascertain if the 

 diamonds of Hindustan can be traced to a 

 similar rock. It may also be in the power 

 of others, more favourably situated than 

 the writer, to ascertain if there be any foun- 

 dation for the vulgar opinion of the con- 

 tinual growth of the diamond. Dr. Brew- 

 ster's opinion that it probably originates 

 like amber, from the consolidation of per- 

 haps vegetable matter, which gradually ac- 

 quires a crystalline form by the influence of 

 time, and the slow action of corpuscular 

 forces, is rather in favour of it than other- 

 wise : it is certain that, in those hot climes 



crystallization goes on with wonderful ra- 

 pidity ; and it is hoped that, at some 

 future period, undeniable proofs may be 

 produced of the re-crystallization of ame- 

 thyst, zeolite, and feldspar in alluvial soil. 



Ranking' s Theory of Fossils. In a for- 

 mer number of this journal, we alluded to 

 Mr. Ranking's Theory of Fossils, of which 

 the following is a correct summary, as well 

 as of the arguments upon which it rests. 

 Whatever fossil bones have been disco- 

 vered"^ Europe, are those of animals em- 

 ployed in the wars of the Romans, and in 

 their sports of the circus, or of such as 

 indigenous to the countries in which they 

 have been found, might have perished from 

 natural causes by a coincidence which can- 

 not be ascribed to chance, the remains of 

 beasts inhabiting at present only distant 

 countries, are never located except in the 

 neighbourhood of some place where the 

 Romans possessed a permanent establish- 

 ment, and consequently a circus ; and ele- 

 phants in particular, only where there is 

 historical evidence to show that it is in the 

 track of a Roman or Carthaginian army. 

 With regard to .Asia, in the northern re- 

 gions of which are such innumerable fossil 

 remains of mammoths, elephants, rhino- 

 ceros's, &c. It is satisfactorily shewn, that 

 countless elephants were slain in the wars 

 of the Mongols, who overran the whole, 

 and especially laid waste the north of Asia ; 

 that rhinoceros's were constantly kept at 

 the magnificent but migratory courts of the 

 Mongol Khans, and that mammoth is only 

 the Siberian name for a walrus, which am- 

 phibious monster abounds along the shores 

 of the frozen ocean, and whose vast tusks, 

 resembling those of the elephant, having 

 given rise to the belief in an extinct species 

 of that mighty animal. The difference be- 

 tween the fossil and living animals is shown 

 not to be greater than what at present exists 

 between animals of the same species, or 

 other than in a few years influence of cli- 

 mate "and circumstances might occasion ; 

 while to account for the great depths at 

 which these remains have been found, Mr. 

 Ranking considers the agency of natural 

 causes during very many centuries is suffi- 

 cient; particularly when it is remarked 

 that no distance below the earth's surface 

 at which animal bones have hitherto been 

 discovered, exceeds that at which fragments 

 of pottery and instruments of war have 

 been met with. 



Specific Gravities. Professor Leslie, of 

 Edinburgh, having invented an extremely 

 delicate apparatus for ascertaining the spe- 

 cific gravity of powders, has deduced the 

 following novel results, which have been 

 communicated to the public through the 

 medium of the Scotsman newspaper. Char- 

 coal, which, from its porosity is so light, 

 that its specific gravity as assigned in books 

 is generally under 0'5, less than half the 

 weight of water, or one-seventh the weight 

 of diamond ; taken in powder, by the above 



