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CHEMICAL SCIENCE. 19 



ric acids, the former attacking it with greatest energy, with evolution 

 of red vapors. It forms two, and probably three oxides, one of them 

 possessing basic properties. When a tolerable quantity of thallium is 

 held on a. loop of platinum wire in a flame, it imparts to the flame a 

 most brilliant green color, and to surrounding objects a very extraor- 

 dinary appearance. If the metal could be obtained in quantity, this 

 ready means of obtaining an intense, homogeneous green light could 

 not fail of being applicable to some useful purpose." According to 

 Mr. Crookes, it produces the simplest spectrum of any known element. 

 Theoretical inquiries into the cause of the spectrum lines, and their 

 relation to other constants of an element, may be facilitated now we 

 know a metal which gives rise to luminous vibrations of only one 

 degree of refrangibility. The remarkable simplicity of the thallium 

 spectrum offers a strong contrast to the complicated spectra given by 

 mercury, bismuth, and lead the metals to which it has the most 

 chemical resemblance. 



The position of the green line does not coincide with any definite 

 line in the solar spectrum. According to Kirchhoff 's theory, we must 

 therefore assume that thallium is not present to any great extent in 

 the sun. Under the highest telescopic power of my apparatus, the 

 line appears to be absolutely identical in refrangibility with a sharp, 

 well-defined line in the barium spectrum, to which Professors Bunsen 

 and Kirchhoff have given the name Bad. 



The spectral green line is an exquisitely delicate test for the pres- 

 ence of thallium, and shows it to be a somewhat widely distributed 

 element. Many specimens of crude sulphur contain it, especially 

 when rather dark-looking. In most cases it is only necessary to set 

 fire to as large a piece of sulphur (less than a pea) as the platinum 

 loop will hold, and when it has nearly burned away, to blow it out, 

 and then introduce it at leisure into the flame of the spectroscope, for 

 the thallium to show its presence by a bright-green line which will 

 flash for an instant into the field of view. 



A NEW METAL IN NATIVE PLATINUM. 



Prof. Chandler, of Union College, in a note to Silliman's Journal, 

 states that some time ago, while examining native platinum from 

 Rogue River, Oregon, he " became convinced of the probable exist- 

 ence of a hitherto unobserved metal. I have deferred publishing my 

 observations, hoping to obtain material for a more complete examina- 

 tion ; in this I have thus far been disappointed. 



" The quantity of platinum examined amounted to only a few 

 grammes. It was digested with hydrochloric acid to remove impuri- 

 ties, and the solution thus obtained was subjected to the ordinary 

 routine of qualitative analysis. 



" A brown precipitate was produced by hydrosulphuric acid, which 

 dissolved readily in hydrochloric acid on the addition of a crystal of 

 chlorate of potassa. In this solution metallic zinc produced a pre- 

 cipitate which resembled metallic tin, obtained under similar circum- 

 stances. This precipitate dissolved readily in hydrochloric acid on 

 the application of heat, but the solution thus obtained had no effect 

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