OF RADIANT HEAT THROUGH DIFFERENT BODIES. 29 



Table II. — continued. 



Deviations of Rays 

 the galvanometer, transmitted. 



o 



Nitric acid (pure and colourless) 5"36 1 .5 



Alcohol (absolute and colourless) 5*30 15 



Hydrate of potassium (colourless) 4*63 13 



Acetic acid (rectified, colourless) 4*25 12 



Pyroligneous acid (of a slightly brown- 

 ish colour) 4-28 12 



Sugared water [eaw SMcree] (colourless) 4*20 12 



Alum water (colourless) 4*16 12 



Salt water (colourless)* 4*15 12 



WHiite of eggs (slightly yellowish) 4*00 1 1 



Distilled water 3*80 11 



Table III. — Crystallized bodies. Common thickness 2"""'62. 



Deviations of Rays 

 the galvanometer. transmitted. 



Mirror-glass 2°l-60 62 



Rock salt (diaphanous) 28*46 92 



Iceland spar (diaphanous) 21*80 62 



Another species (diaphanous) 21*30 61 



Rock crystal, colourless (diaphanous)... 21*64 62 

 Rock crystal, smoky (diaphanous and 



very decidedly brown) 20*25 51 



Brazil topaz, colourless (diaphanous) ... 19*18 .54 



Carbonate of lead (diaphanous) 1 8*35 52 



White agate (translucid) 1 2*48 35 



Sulphate of barytes (veined, dully dia- 

 phanous) 11*72 33 



Emerald (diaphanous, of a light blue)... 10*16 29 



Yellow agate (translucid, yellow) 10*10 29 



Borate of soda (translucid) 9*87 28 



Green tourmaline (diaphanous, green)... 9*54 27 



Adularia (diaphanous, dull, veined) ... 8*30 24 



Sulphate of lime (diaphanous) 7*15 20 



Fluate of lime (diaphanous, dull, veined) 5*40 15 



Citric acid (diaphanous) 5*15 15 



Sardoine (translucid) 4*98 14 



Carbonate of ammonia (diaphanous, dull, 



striated) 4*50 13 



Tartrate of potash and soda (diaphanous) 4*40 12 



Alum, crystal (diaphanous) 4*36 12 



Sulphate of copper (strongly diaphanous, 



blue) 0*00 



• In this solution we used very diaphanous pieces of rock salt ; the same may 

 be said of the solution immediately preceding — the water was completely satu- 

 rated with the alum. 



