This study was designed to evaluate the effects of internal droplet convection on the extraction that occurs during generation of a dispersed phase. A photographic determination of dispersed-phase controlfed mass transfer from liquid droplets in the formation stage demonstrates a strong dependence on formation time. Convection appears to control mass transfer during rapid drop formation, but an abrupt transition in transfer coefficient occurs as time of formation increases. Diffusion calculations overestimate total extraction for long formation times.

The mass transfer occurring between a liquid drop during its formation and the surrounding liquid phase was directly evaluated by a photographic technique. Slightly soluble organic drops containing no additional solute were formed in a continuous aqueous phase so that only the continuous phase resistance existed. Effects of nozzle diameter and both phase flow rates were evaluated and the possible influence of surfactant was investigated.Mass transfer coefficients were observed to decrease sharply with time early in the formation period. This, together with the parametric study of dispersed phase feed rate, indicates the strong effect of internal drop convection for this high Schmidt number system. The measured coefficients are substantially higher than would be expected for free drops.

An interferometric investigation of the transfer of n-and iso-butyl alcohols from water to carbon tetrachloride revealed the existence of large interfacial resistances (500 to 2,500 sec./cm.) attributable to the presence of surface active agents. Evidence of a solute-surfactant interaction has been obtained with sodium dodecyl sulfate and sodium tetradecyl sulfate, but the effect appears to be much less pronounced with the shorter chain length surfactant or with the branched chain alcohol.The influence which surface active agents exert on the transfer rate of a solute between immiscible phases may be either beneficial or deleterious. Since there are several competing mechanisms by which this effect may be gen- Preliminary ProcedureThe cell components were cleaned in a sodium dichromatesulfuric acid cleaning solution prior to each run, with the exception of the stainless lines which were rinsed thoroughly with distilled water and reagent grade methanol and dried with filtered air. The glass windows were treated such that the surface that was to contact the organic phase in the assembled cell was hydrophobic and oleophilic, while the surface in con-

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The control of ion fluxes to and from bone has important implications to mineralization and calcium homeostasis. Since ionic transport frequently results in an electrical potential difference across the layer of cells lining bone surfaces, knowledge of this potential is critical to understanding the means of regulation of ionic concentrations in the interior bone fluid phase. This work presents a determination of a metabolism-related electrical potential difference by a thermodynamic argument based on the distribution of charged and uncharged tracers between the bone extracellular fluid compartment and the bathing medium. For embryonic chick calvaria whose viability was assured by oxygen consumption measurements, an electrical potential of 4 mV was determined, positive with respect to the bone fluid compartment. This measurement is shown to be consistent with the active transport of K+ ion into the interior of bone; the potential developed by this transport process will then exclude from the interior phase a passively leaked Ca2+ ion.