Isinglass
A very pure form of gelatine prepared from the entrails and air-bladders of fish, notably the sturgeon. It is semi-transparent when pure, and this may perhaps account for applying the name to the sheets of mica employed for sight-holes of cupolas, stoves, etc.
Isinglass is an excellent material for making elastic moulds for obtaining plaster casts. See ELASTIC MOULDS.
Isosceles Triangle is a triangle which has two equal sides.