A bottle containing 5gms of pH indicator

circa 1960

A bottle containing 5gms of pH indicator

circa 1960

A bottle containing about 10 gms of haematoxylin pH indicator made by Griffin & George Limited

circa 1960

A bottle containing 5gms of pH indicator

circa 1960

A vial containing 1gm of pH indicator

circa 1960

A vial containing 1gm of pH indicator

circa 1960

A bottle containing 25 gms of Ehrlich Haematoxylin

circa 1960

A 100ml bottle of Alkaline methylene blue

circa 1960

A bottle containing 5gms of pH indicator

circa 1960

A metal vial containing 5gm of pH indicator

circa 1960

A bottle containing 5gms of pH indicator

circa 1960