Today my sister read my last post and she found and scanned my mother’s recipe. Here it is. 
For those of you who are unable to translate my Mum’s handwriting, I will type it out.
Magic Garden
6 tbsp salt
6 tbsp liquid blueing
6 tbsp water
1 tbsp ammonica
Pour over broken bricks,coal,stones etc.
Rub sides of shallow dish with vaseline.
(I remember my mother used a glass or pyrex pie plate. )
