158 



Intelligence and Miscellaneous Articles. 



was decomposed by sodie carbonate and nitrate, and a third for the 

 determination of the alkalies by J. L. Smith's method. The V 6 O n 

 given below is the mean of the two determinations, b (another 

 sample, not quite as pure as a) was analyzed by fusion, c, still 

 more contaminated with impurities, was analyzed by dissolving in 

 dilute sulphuric acid in a sealed tube, &c. : ca is the result of this 

 aualysis ; cp after deducting 11-45 per cent, of impurities, d 

 (another sample) was decomposed by dilute hydrofluoric acid ; the 

 analysis was unfortunately lost, excepting the determinations given 

 below ; the material for this analysis had not been dried over sul- 

 phuric acid. e. This sample was dried over sulphuric acid for 

 several weeks ; a portion, which was decomposed by sulphuric acid, 

 gave 5-37 per cent, insoluble silicates, 0*23 per cent, of gold, and 

 43*24 per cent, of silicic acid ; the Y 6 O u was determined by dif- 

 ference. The results given below were obtained by decomposing 

 the mineral by fusion. 





a. 



b. i ca.. 



00. 



d. 



e. 



Insoluble silicates, ] _ 

 quartz, gold, &c. j - 



Si0 2 = 



A1„0 3 — 



[0-85] 



47-69 



1410 

 1-67 

 200 



trace 

 019 

 759 



2202 

 4-96 



11-45 



4782 43-46 

 12-60 ! 10-52 



48-60 

 11-76 

 227 

 1-95 

 023 

 0-34 

 5-98 

 22-92 

 5-95 



8-91 



J5-96 

 634 



[5-60] 



46-81 



15-78 

 1-58 

 2-31 



trace 

 0-60 

 8-89 



2016 

 3-87 



Feb = 



MgO = 



CaO = 



Na 2 (trace Li 2 0) = 

 K 2 = 



y a o„ - 



3-30 

 2-43 



trace 

 033 

 803 



21-36 

 513 



2-03 

 1-74 

 0-20 

 0-30 

 5-35 

 20-50 

 5 32 



Ignition — 





; 100-22 



101-00 100-87 



10000 





10000 



A mineral very similar in composition, and perhaps a compact 

 impure variety of Roscoelite, is found associated with the scales. It 

 has the appearance of a massive dark green chlorite, or that of some 

 varieties of serpentine. The analysis was made by fusion &c, 

 and gave :— gi (^ =46-09 



A1 2 3 =17-46 



FeO = 1-95 



MgO = 2-18 



Na 2 = 0-18 



K 2 O = 8-66 



V c O n =17-53 



Loss by ignition . . = 6-37 



Silliman's American Journal, July 1876. 



ON HEAT-SPECTRA. BY M. AYMONNET. 



M. Desains showed, in 1868 : — (1) that if a body is heated to 

 different temperatures, the increase of energy of its radiation affects 

 both the luminous and the obscure portion ; (2) that when the 

 heat-spectra given by different sources are considered, the position 

 of the maximum of intensity varies with the nature of the sources . 



