School of Physics Lecture Demonstration Manual

Ob-2 Matching Refractive Indices (Wool in Methyl Salycilate)

Published: Wednesday 15 March 2006 - Updated: Thursday 19 April 2007

Aim

To demonstrate why you should not wear woollen clothes when swimming in a bath of methyl salycilate.

Apparatus

Diagrams

Click on pictures to enlarge.

Matching Refractive Indices Diagram

Description

A large cylindrical beaker is divided into two portions by a sieve of glass rods. The upper portion contains a wad of wool that appears opaque; the lower portion contains methyl salycilate. Wool on absorbing this chemical becomes transparent. If the beaker is now inverted allowing the chemical to saturate the wool an object previously hidden in the wool becomes visible.

Safety notes

Sharps safety

Maintenance

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