Chapter XI: PHYSICS.--Iridescent Crystals.--By LORD RAYLEIGH.--An

abstract of a lecture by the distinguished physicist,
detailing some interesting experiments applicable to the
colored reflection observed in crystals of chloride of
potash.--1 illustration. 11366

Transmission of Pressure in Fluids.--By ALBERT B.
PORTER.--An apparatus for illustrating the laws of
transmission of pressure in fluids, suitable for lecture
purposes.--1 illustration. 11362