“dancing in the air.”  The very same effect is perceived when we look at objects through spirits and water that are not perfectly mixed, or when we view distant objects over a red hot poker or over a flame.  In all these cases the light suffers refraction in passing from a medium of one density into a medium of a different density, and the refracted rays are constantly changing their direction as the different currents rise in succession.  Analogous effects are produced when sound passes through a mixed medium, whether it consists of two different mediums or of one medium where portions of it have different densities.  As sound moves with different velocities through media of different densities, the wave which produces the sound will be partly reflected in passing from one medium to the other, and the direction of the transmitted wave changed; and hence in passing through such media different portions of the wave will reach the ear at different times, and thus destroy the sharpness and distinctness of the sound.  This may be proved by many striking facts.  If we put a bell in a receiver containing a mixture of hydrogen gas and atmospheric air, the sound of the bell can scarcely be heard.  During a shower of rain or of snow, noises are greatly deadened, and when sound is transmitted along an iron wire or an iron pipe of sufficient length, we actually hear two sounds, one transmitted more rapidly through the solid, and the other more slowly through the air.  The same property is well illustrated by an elegant and easily repeated experiment of Chladni’s.  When sparkling champagne is poured into a tall glass till it is half full, the glass loses its power of ringing by a stroke upon its edge, and emits only a disagreeable and a puffy sound.  This effect will continue while the wine is filled with bubbles of air, or as long as the effervescence lasts; but when the effervescence begins to subside, the sound becomes clearer and clearer, and the glass rings as usual when the air-bubbles have vanished.  If we reproduce the effervescence by stirring the champagne with a piece of bread the glass will again cease to ring.  The same experiment will succeed with other effervescing fluids.—­Sir David Brewster.

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No man is so insignificant as to be sure his example can do no hurt.

—­Lord Clarendon.

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THE PUBLIC JOURNALS.

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PADDY FOOSHANE’S FRICASSEE.

Paddy Fooshane kept a shebeen house at Barleymount Cross, in which he sold whisky—­from which his Majesty did not derive any large portion of his revenues—­ale, and provisions.  One evening a number of friends, returning from a funeral—–­all neighbours too—­stopt at his house, “because they were in grief,” to drink a drop.  There was Andy Agar, a stout, rattling fellow, the natural