OF RADIANT HEAT THROUGH DIFFERENT BODIES. 45 
Transmissions 
from 100 rays of heat issuing from 
Names of the interposed substances i 
(common thickness, 2°™-6:) Astehe blackened|blackened 
Leedtelli descent heer tio Ie ete 
lamp. platina. 390°(732°)|100°(212°) 
Rock salt (diaphanous, colourless) 
Fluate of lime (diaphanous, colourless) 
Rock salt (diaphanous, dull) 
Beryl (diaphanous, greenish yellow)... 
Fluate of lime (diaphanous, greenish) 
Iceland spar (diaphanous, colourless)... 
Another species (diaph., colourless) ... 
Mirror glass (diaphanous, colourless)... 
Another kind (diaph., colourless) 
Rock crystal (diaphanous, colourless 
Rock crystal, smoky (diaph., brownish 
Acid chromate of potash (a vivid orange 
White topaz (diaphanous, colourless 
Carbonate of lead (diaph., colourless)... 
Sulphate of barytes, pure, (diapha- 
nous, rather dullish) 
White agate (translucid, pearly ) 
Adularia felspar (diaph., dull, veined) 
Amethyst (diaphanous, violet) 
Amber, artificial (diaph., yellow) 
Emerald (diaph. bluish green) 
Agate, yellow (translucid, yellow) 
Borate of soda (translucid, white) 
Green tourmaline (diaph., deep green) 
Cowhorn (translucid, hazel) 
Common gum (diaph., yellowish) 
Sulphate of barytes (diaph., dull veined) 
| Sulphate of lime (diaph., colourless)... 
Sardoine (translucid, brown) 
Citric acid (diaphanous, colourless) .. 
Carbonate of ammonia (diaphanous, 
dull, striated) 
Tartrate of potash and soda (diapha- 
- nous, colourless)... 
Amber, natural (translucid, yellowish) 
Alum (diaphanous, colourless) 
Glue, strong (diaph., yellowish brown) 
Mother-of-pearl (translucid, white) .. 
Sugar-candy (diaphanous, colourless) 
Green fluate of lime (translucid, mar- 
__ bled green)... 
Melted sugar (diaphanous, yellowish)... 
Ice very pure (diaphanous, colourless) 
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