I'm trying to find out origins of common sayings such as 1. "don't throw out the baby with the bath water" or 2. "raining cats & dogs".
1. In the old days the men got to take the first baths and on down the line of the family. By the time the baby was bathed the bath water was very dirty, hence the saying.
2. Also in the old days, roofs were made of thatch. Often cats or other small animals would sleep on the roofs. When it rained they could fall through the roof.
I thought they were called idioms but apparently not. I'd like to find a book on sayings and the meanings behind them.