184: 



METALS. 



METEORS AND METEOEITES. 



of their atomic weights ; but when the amount 

 of copper was increased, that metal dissolved 

 faster than did other alloys containing an ex- 

 cess of zinc. An alloy, containing nearly equal 

 parts, by weight, of copper and zinc, was uni- 

 formly dissolved by nitric acid of specific grav- 

 ity 1.14, but when a more dilute acid was em- 

 ployed, one having the specific gravity of 1.08, 

 the zinc and copper were dissolved in the pro- 

 portion of 5 to 1, by 24 hours' immersion. The 

 same alloy, when treated with concentrated 

 hydrochloric acid, lost only the zinc ; a cube of 

 spongy copper remaining undissolved. Alloys 

 containing more than two atoms of zinc to one 

 of copper were rapidly attacked by dilute 

 nitric acid of specific gravity 1.10. Those con- 

 taining copper in excess were protected from 

 the action of concentrated hydrochloric acid ; 

 while those with an excess of tin dissolved 

 much more readily than the individual metals. 

 All alloys of copper and tin were to some extent 

 protected against the action of concentrated 

 sulphuric acid. 



The Action of Platinum, Ruthenium, Ehodi- 

 um, and Iridium on Chlorine Water. On 

 introducing platinum black into strong chlorine 

 water, numerous bubbles of oxygen are devel- 

 oped. Freshly prepared spongy platinum has 

 the same effect. Spongy ruthenium acts much 

 more powerfully than platinum ; 0.15 grammes 

 placed in strong chlorine water, caused such an 

 active disengagement of oxygen, that the pieces 

 of spongy metal were carried to the surface by 

 the gas. Rhodium acts similarly to ruthenium, 

 and more strongly than platinum. Pulverulent 

 iridium only causes a feeble decomposition. 

 The four metals, like light, act' very slowly on 

 iodine and bromine waters. Solutions of hypo- 

 chlorous salts, on the contrary, are very quickly 

 decomposed, even in the dark, an active dis- 

 engagement of gas taking place. In these cases 

 the four metals seem to act with the same de- 

 gree of power as in the transformation of chlo- 

 rine water into hydrochloric acid and oxygen. 

 (Chem. News, May 4, 1866.) 



The Sodium-amalgamation Process. The ap- 

 plication of sodium amalgam to the ordinary pro- 

 cess of extracting gold and silver from their pow- 

 dered ores, proves practically to be a success. 

 The Colorado Journal says, that by the use of the 

 sodium amalgam, the yield of the Narragansett 

 mill has been increased more than 30 per cent. 

 In another mill in the same vicinity, four days 

 running with mercury prepared by the sodium 

 amalgam, yielded 1 oz. 19 dwts. more gold than 

 four days' operations without it. The amalgam 

 has been tried at the Lake Major mine in Nova 

 Scotia, on refuse pyrites, from which 5 oz. of 

 gold per ton were taken. The result exceeded 

 the most sanguine expectations of the expe- 

 rimenter. Trials at various mills in Califor- 

 nia have been equally encouraging. There is 

 no doubt that the process is an improvement 

 on the common method of amalgamation, but 

 its adoption is not likely to be general until 

 sodium is manufactured in this country, and 



furnished at a moderate price. There hav 

 also been some prejudices against the use of 

 the amalgam, on account of the highly com- 

 bustible qualities of the unalloyed sodium. 

 When combined with mercury, however, so- 

 dium is harmless, and may be transported with- 

 out deterioration in air-tight cans. 



At the January session of the National Acad- 

 emy of Science, Prof. Silliman read a paper 

 detailing a series of experiments made by him 

 with the sodium amalgam. In one trial made 

 on over 500 pounds of low grade ore worth 

 about $15 a ton, all the gold was extracted 

 that existed in the sulphides. The operation 

 was conducted in a large-sized Freiburg amal- 

 gamator, and the sodium amalgam was added 

 in four successive portions of 1 oz. each, dis- 

 solved in a portion of the 20 Ibs. of mercury 

 employed, the proportion of the former being 

 about 1.2 per cent, of the total quantity of mer- 

 cury used. In a second series of experiments 

 on ore worth about $320 a ton, treated in a re- 

 volving barrel, 83.3 per cent, of all the gold 

 present was saved, against 40 to 60 per cent, by 

 the common method. 



METEORIO IRON. Mr. J. Lawrence Smith 

 has reported to the American Journal of Sci- 

 ences and Arts, the results of his analysis of a 

 specimen of meteoric iron found in Russel 

 Gulch, Colorado Territory. The mass measured 

 in its extreme length, breadth, and thickness: 

 8Jin. x T^in. x 5 in., and weighed 29 Ibs. 

 The iron was of medium hardness, with a den- 

 sity of 7. 72, and when cnt through was found 

 to contain a few small nodules of iron pyrites. 

 It resisted the action of air and moisture very 

 well ; but was readily attacked by nitric acid. 

 No silicious minerals could be traced in any of 

 the crevices of the mass. Its composition 

 proved to be : 



Iron, 90.61 



Nickel, Y.84 



Cobalt, 73 



Copper, minute quantity. 



Phosphorus, 02 



99.25 



Mr. Smith states that he has found copper in 

 all the specimens of meteoric iron that he has 

 examined. 



METEORS AND METEORITES. The year 

 1866 was, as had been anticipated, marked by 

 the occurrence of an unusually brilliant display 

 of" shooting stars," so called, at the recognized 

 November period, and visible over portions of 

 the Eastern Continent and of the Atlantic 

 Ocean the exhibition, indeed, being such as 

 to justify its being regarded as answering to 

 the supposed secular or 33-yearly periodical 

 return of that phenomenon. This "shower" 

 will presently be considered. The reader is 

 referred also to the articles METEOES, etc., and 

 ATMOSPHEEE, in the preceding volume. 



November Period, 1865. Observations in 

 different parts of England, on the night of No- 

 vember 12-13th, showed a more than usual 

 number of meteors, even for thi? period (in or- 



