Experiment 46—Test to Distinguish Artificial Silk from Silk
Apparatus: Porcelain dish, potassium hydrate.
Material: Piece of silk fabric.
Reference: Textiles, page [240].
Since silk fabrics, particularly hosiery, are becoming popular, various attempts have been made to produce substitutes for real silk. To test a silk fabric, boil the sample in 4 per cent potassium hydrate solution and note the effect. If it produces a yellow solution it is artificial silk, if colorless it is pure silk.
Another simple way used by some workmen, although unhygienic, is to unravel a few threads of the suspected fabric, place them in the mouth, and masticate them vigorously. Artificial silk will soften under the operation and break up into a mass of pulp. Natural silk will retain its fibrous strength.
Test various samples of cheap “silk” hosiery.
Experiment 47—Test to Distinguish Silk from Wool
Apparatus: Porcelain dish, hydrochloric acid.
Material: Silk or woolen fabric.
Reference: Textiles, page [240].
Silk may be distinguished from wool by putting the suspected thread or fabric into cold concentrated hydrochloric acid. If silk is present it will dissolve, while wool merely swells.
Test various samples of silk and wool.