Precipitin tests which occur over a narrow range of antigen-antibody ratio, due chiefly to peculiarities of the antibody (precipitin). (From Stedman, 26th ed)
Flocculation
The aggregation of suspended solids into larger clumps.
Water
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)