348 Miscellaneous Intelligence. 



sides some insoluble salts of lead in the pores of the cloth to give 

 stability to the tint, but in all cases the colours must be height- 

 ened at last by passing them through boiling water. 



The scarlet sub-chromate is extremely beautiful when ground up 

 with oil, and possesses great body as a pigment. It is not de- 

 graded in its hue like vermilion by admixture with white lead ; 

 it mingles with other colours, and shews no signs after long ex- 

 posure, of any change by time. As a water colour it has not been 

 tried sufficiently to authorize a positive declaration that it will 

 not blacken ; but several pieces of cards and thin paper painted 

 with it, and hung up in situations likely to influence the colour of 

 salts of lead have not in some months perceptibly diminished in 

 brightness. Mr. Badams observes that should it succeed, no tint 

 would be a more desirable accession to the pallet than a bright 

 and permanent scarlet or scarlet-orange. 



20. Cadmium in Ireland. —Upon examining a slag produced 

 during the smelting of galena, Mr. A])jolin discovered cadmium 

 in it in considerable abundance, amounting to as much even as 5 

 per cent. This is stated to be the first time the metal has been 

 found in Ireland, but there is no intimation from whence it came 

 or where the galena works are situated. The slag was pulverized 

 and digested innitric acid, the filtered solution was precipitated 

 by sulphate of soda, again filtered, treated with caustic ammonia 

 in excess, the iron separated removed by the filter, the clear 

 solution evaporated, and the oxides gradually thrown dowm. These 

 dissolved in muriatic acid, were treated with carbonate of am- 

 monia in such excess as to dissolve any zinc at first thrown down. 

 An insoluble part was obtained, which being well washed, 

 was dissolved in muriatic acid, the solution introduced into a 

 platinum capsule with a piece of zinc in Dr. Wollaston's man- 

 ner, and next day the cadmium was found lining the crucible, 

 and easily freed from the supernatent solution by washing. 

 The metal when examined had all the cliaracters of cadmium.— 

 Dublin Phil. Jour., i. 73. 



21. Explosion of fulminating Powders. — There is an old notion 

 that fulminating powders act more powerfully downwards than 

 in any other direction. We take the opportunity of remarking on 

 it here, in consequence of an essay on this subject by M. Brianchon, 

 which is noticed at considerable length in the Bil), Universelle, 

 xxviii. 293, and from having heard many persons express an 

 opinion of the same kind. The opinion has arisen no doubt from 

 the difference of effect observed, when these preparations, such as 

 fuminating gold or silver, have been exploded on a horizontal sur- 

 face, and compared with the explosion or. rather perhaps inflam- 

 mation of gunpowder in the same circumstances. A very gre?it 



