or…
17.19
Q.S
Quantum satis (abbreviation q.s. or Q.S.) is a Latin term meaning the amount which is enough.
4500 is enough…?
medical term…
“add enough solvent or any other material which is used in bulk to bring the total volume to…” For example, “Q.S. to 500 ml” means “whatever volume you have now, add the necessary amount to make the total volume upto 500 ml.”