Her comes the math.
Do you have a kitchen scale?
For 400mg you need ***** by weight. You may need to hit the po, drug store, or grocery to find a good scale...then measure what that amount will be in terms of 1/4 cup or whatever and repeat that way.
Wait a sec...I don't think I did that right.
I...
I think I can help...
When you look at the bottle does it say something like 100mg/ml?
Is this what you have?
http://www.culpeperfeed.com/Duramycin-10-p/drvt0003.htm