Consumer Reports, among others in the 50s, said that recently introduced fabric softeners would put a yellowish coating on clothes that dulled whites and bright colors so bluing was added to many softeners to counteract the dulling effects. I wonder if that is why the bottled liquid starches were blue?
Does anyone remember growing a salt garden on coal? Mrs. Stewart's was added to the water.
OOH! OOH! Does anyone remember those magic rock gardens where you got a small, approx. (4" L X 3" H X 1" D) rectangular plastic tank, water glass (sodium silicate) and some small chunks of colored solids? You put the chunks in the tank filled with water glass and they started to become stlagmites, growing into colored spires in the tank over a period of days. After that there was not much action and they would break if jostled. I just checked and they are still being made by the son of one of the two brothers who invented them.
Yep, sure do remember those, had a set. If one didn't have a deep enough container, they would form flat "pads" when they reached the surface of the water