Your structure is off. You should have each ingredient be its own record in a related table.
Compound W ;)
Salicylic Acid 14.2
Glacial Acetic Acid 11
Thanks Mr Vodka
... please forgive my ignorance, but I don't quite know how to apply your solution...
Are you saying that the amount fields in the compounds table should write to the corresponding field in the ingredients table?
Please forgive my noobishness :-p
Well if you include your existing ingredient table, then you will have a total of 3 tables.
Components will store the foreign keys of MixtureID and IngredientID. Each ingredient and amount that makes up the mixture will be a new record in the component table. Does this make sense? You can use a portal to display / add ( if allow creation is turned on ) the components that make up the Mixture.
Thanks for your patience Mr Vodka. I'll try to implement this!