Kinetic data are needed to develop basic understanding of fermentation processes and to permit rational design of continuous fermentation processes.The kinetics of the fermentation of glucose to lactic acid have been studied at six constant pH levels between 4.5 and 6.0 by measuring the instantaneous rates of bacterial growth and of lactic acid formation throughout each fermentation.It was found that the instantaneous rate of acid formation dP/dt, should be related to the instantaneous rate of bacterial growth dN/dt, and to the bacterial density N, throughout a fermentation at a given pH, by the expression dP dtwhen the constants ␣ and ␤ are determined by the pH of the fermentation.

Kinetic data are needed to develop basic understanding of fermentation processes and to permit rational design of continuous fermentation processes. The kinetics of the fermentation of glucose to lactic acid have been studied at six constant pH levels between 4.5 and 6.0 by measuring the instantaneous rates of bacterial growth and of lactic acid formation throughout each fermentation. It was found that the instantaneous rate of acid formation dP/dt, should be related to the instantaneous rate of bacterial growth dN/dt, and to the bacterial density N, throughout a fermentation at a given pH, by the expression when the constants α and β are determined by the pH of the fermentation.

Summary. Steady-state and transient equations are derived for continuous-flow fermentation processes. Analytical as well as graphical methods for predicting from batch data the performance of single-or multi-stage continuous fermentations are developed. The criteria for stability are also examined. Actual experimental measurements of continuous lactic acid fermentations conducted at controlled pH levels agree with the theory developed.

facture and distribution of a serum for preventive inoculation introduced by Haffkine. During the period in which the labora¬ tory has been in existence the number of doses issued has amounted to 5,750,000, of which 250,000 has been sent to countries outside of India. It is claimed that the death rate of the inoculated is only one-sixth of that of the non-inoculated. The number of attacks is less than a third of that in the noninoculated and the proportion of deaths to attacks is less than 25 per cent., or less than one-half of that in the non-inoculated.