Page:Scientific Memoirs, Vol. 1 (1837).djvu/40

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28
M, MELLONI ON THE FREE TRANSMISSION

the heat, the lamp was brought nearer and nearer until we obtained, through the combination of the three plates, the same indication of 19° that was furnished by the thick glass when exposed singly to the radiation of 30°.

Table I.—Glass (uncoloured). Common thickness 1ᵐᵐ·88.
Deviations of
the galvanometer.
Rays
transmitted.
°
No screen 30·00 100
Flint-glass (of Guinand) 22·90  67
Flint-glass (English) 22·43  65
Flint-glass (French) 22·36  64
Another kind 22·19  64
Mirror-glass 21·89  62
Another kind 21·10  60
Another kind 20·78  59
Crown-glass (French) 20·58  58
Window-glass (common) 19·25  54
Another kind 18·56  52
Another kind 17·83  50
Crown-glass (English) 17·22  49


Table II.Liquids. Common thickness 9ᵐᵐ·21.
Deviations of
the galvanometer,
Rays
transmitted.
°
Mirror-glass 19·10 53
Carburet of sulphur (colourless) 21·96 63
Chloride of sulphur (of a strong brownish red colour) 21·83 63
Protochloride of phosphorus (colourless) 21·80 62
Hydrocarburet of chlorine (colourless) 13·27 37
Nut-oil (yellow) 11·10 31
Essence of turpentine (colourless) 10·83 31
Essence of rosemary (colourless) 10·46 30
Oil of colza (yellow) 10·38 30
Oil of olives (greenish yellow) 10·35 30
Naphtha (natural—a light brown yellow)  9·77 28
Balsam of copaiba (a sufficiently decided brown yellow)  9·39 26
Essence of lavender (colourless)  9·28 26
Oil of pink [huile d'œillet] (very slightly yellowish)  9·26 26
Naphtha (rectified, colourless)  9·10 26
Sulphuric æther (colourless)  7·59 21
Pure sulphuric acid (colourless)  6·15 17
Sulphuric acid (of Nordhausen, of a sufficiently decided brown)  6·09 17
Hydrate of ammonia (colourless)  5·47 15