A new inertial drive flow system has been developed for doing quench flow reaction kinetics in the investigation of the mechanism of reaction of Sacroplasmic Reticulum, ATPase, and other enzyme systems which cannot be followed by optical means. A time resolution of better than 1.5 ms has been achieved to date using the acid quenching of the reaction of 2-4 dinitrophenyl acetate as the test reaction. 0.25ml of each reagent are required per data point in contrast to 2.5 ml for other instruments. Extension of its use for cryoquenching at -40 degrees C is planned for the coming year. The use of this drive in our zero pressure drop thermal stopped flow system was reported last year. Pressure, velocity, and thermal measurements underway over a series of viscosities have provided information needed for the support of the ball mixer theory, i.e. that mixing is mainly the result of changing linear momentum to angular momentum. The results to date demonstrate that for a viscosity of one centipoise a pressure differential of less that 10 psi is sufficient to produce better than 99% mixing at 3 M/sec with thermal fluctuations of only plus/minus 2m degrees C. In addition optical fiber sensors will be added in the coming year so that simultaneous thermal-optical stopped flow experiments may be done.