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Chemistry and Physics. * 07 
even with the smallest bape eat This glass is particularly adapted 
the recognition of soda in all its compounds. The sensibility is sgg4g_ 
mgrm. ‘The test is to i. me hice with sulphuric acid; dried and held 
in the hottest point of the flame 
ithia gives a carmine red flame-color which appears violet red through 
the blue, wiry ae through the violet but is invisible through the green 
glass. The test is to he ene with sulphuric acid and treated like 
potash, the Leouititity 4 is rza'soo Mgrm. In the presence of soda, lithia 
is recognized through the blue glass; in the presence of ger by the 
m 
glass; through the green glass, the soda flame appears orange ss at 
to 
to be moistened with sulphuric acid, carefully dried, and held in the hot- 
test point of the mantle. After all the alkalies have evaporated, the earths 
may be detected. 
Baryta may be recognized by the Baeble green flame-color which 
{the ae green through the green glass. The aes for baryta 
aione 1s gz55 mgrm. If the green snanipban and a red flame-color makes 
its appearance, the ng t is to oS re eatedly moistened with sbi se 
of muriatic acid, appears siskin green through the green glass. Stronti 
gives in this case a weak yellow. The sensibility of aL alone is zo/ga 
mgrm sites by employing the green oss 38 te 
Stron may be recognized by the urple or rose hdien which is seen 
vine hs blue glass when the — after mpistening with muriatic acid, 
18 evaporated to dryness in the flam 
Copper as chlorid gives an azure bhae zone, and as cae a pure green 
flame-color. By the combined observation of both colors may be 
distinguished ral all othiae metals which give similar colors. The sensi- 
bility of copper alone is zy'yy Mgrm. The other flame-coloring metals, 
such as arsenic, antimony, tin, lead, mercury id zinc, exhibit especially 
in the form of ‘chlorids, more or less intense bluish or greenish mantle- 
colors, which however cannot be advantageously used - venience for the 
metals themselves.—Journal fur prakt. Chemie, No. 16, 1860. 
4. The Dichroscope-—The apparatus to which Prof. Deve has given this 
hame is vied for the following purposes 
-) To esent interferences, and spectin’ in different-colored light, 
both 1 separately and combined. 
To imitate the phenomena of dichroism, both in the case in which 
dich rei crystals are viewed throug Haidinger’ s rhomb of eale spar, and 
in the case of the phenomena produce “ when the dichroitic a ere§ 
themselves are used as analyzers in a polariscope. a 
(3.) To combine Hoes mace sreatalys ps ceva, polarzed and 
unpolarized light, not in such a manner that the one is p ueed by the 
polarizing, and the ather by the Hen sabe | bie ems oa 0 od 
traverse the ot area Sane a 
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