404 Scientific Intelligence. 
Atropia and potash mixed together and exposed to a red heat, 
yield ashes, which, when mixed with muriate of iron, strike a 
lively red colour. The alkali from the Hyoscyamus even 
when heated to redness with charcoal, is not easily altered. It 
crystallises in long prisms, and when saturated with sulphuric 
acid, and especially with nitric acid, forms very characteristic 
salts.~See Journ. de Pharm. and Ann. of Phil. No. 91, p. 69. 
14. Curious Experiment with Iodine . — According to Van 
Mons, if we dissolve some iodine in muriatic acid, and pour am- 
monia over the solution, so that the two liquids do not mix, the 
iodine will in a short time crystallise between the two liquids, in 
fine pyramids, having their bases turned towards the surface of 
the liquid. 
1 5. Native Combination of Sulphate of Ba rium and Fluoride 
of Calcium . — This singular substance, obtained in Derbyshire 
many years ago, has been recently examined by Mr Smithson. 
It formed a vein about an inch wide in a coarse shell-limestone. 
Next to this substance was a layer of crystals of sulphuret of' 
lead ; and between these and the limestone-rock, a layer of cry- 
stals of carbonate of calcium. This compound substance is so 
like fine compact grey limestone, that the eye cannot distinguish 
them. Its specific gravity is 3.750, and it consisted of 
S ulphate of barium , 51.5 
Fluoride of calcium, 48.5 
100.0 
‘‘‘ This mineral,” says Mr Smithson, presents us with a re- 
markable case of combination, that of a neutral salt with a body 
wfiiich is not a salt, but belongs to an order which is analogous 
to metallic oxides. I have met with another instance of the 
kind. I have examined transparent crystals composed of anhy- 
drous sulphate of calcium, and chloride of sodium.'” — Ann. of 
Phil No. 91. p. 49. 
16. Flame of Hydrogen rendered luminous . — Dr Hare of 
Philadelphia has rendered the flame of hydrogen luminous like 
that of oil, by adding a small quantit}^ of oil of turpentine to the 
usual mixture for generating that gas. The light seems greater 
tlian that of carburetted hydrogen. He found also that the ad- 
