1. Actively growing pneumococci produce acid at such a rate that change in the pH of the medium parallels change in rate of growth. 2. The death of the pneumococci is not followed by change in the reaction. 3. Acidification during growth in beef infusion media proceeds until a pH of about 7 is reached. At this point growth stops. The increase in hydrogen ion concentration is not the only origin...

In the first paper of this series (1) a model for microheterogeneity of plasma albumins was presented together with some critical evidence in support of its adoption. According to this model plasma albumin consists of a very large number of similar molecular species. The N-F transition of the protein as observed by electrophoresis, solubility, optical rotatory dispersion, and other methods is a...

A convenient and accurate method is described for the electrometric determination of the hydrogen ion concentration of small amounts of fluid (0.015 to 0.020 cc.). The suitability of such a method for work on insect blood and body fluids is particularly pointed out.

cept for the first time, has probably wondered why chemists employ a scale for measuring hydrogen ion concentration which decreases in value as the concentration of the H+ ion increases and vice versa in other words, a scale in which a solution of pH = 1 is actually more acidic, rather than less acidic, than a solution having a pH = 14. The less mathematically inclined are also likely to be puz...

The hydrogen ion concentration in the lesions of experimental pneumococcus infection has been estimated directly by pH determinations on exudates from living animals. For indirect evidence of an increase in hydrogen ion concentration within the lesions, the difference in sugar content between exudate and blood from animals with pneumococcus infection has been measured. With sanguinous exudate f...

Evidence is given of the presence in the cellular material obtained from the pneumonic lung of a proteolytic enzyme digesting coagulated blood serum at hydrogen ion concentrations of 7.3 to 6.7 and inactive at higher; i.e., more acid concentrations. In addition, evidence is brought forward of the presence in the cellular material from the pneumonic lung of a proteolytic enzyme splitting peptone...

The effects of hydrogen ion concentration on plant growth occupy a prominient position in discussions of the adaptability of plants to their nutrient eiivironmelit. In the last two decades, with the improvements of methods of measurinig pH and particularly with the widespread adoption of the (lass eleetrode, increasing attention has been given to the hydrogen ion coneenitrationi in soils as it ...

Ever since Henderson in 1908 introduced Guldberg & Waage’s Law of Chemical Equilibrium (1867) in biology applied to the dissociation of carbonic acid, new studies on the first dissociation exponent of carbonic acid in plasma have appeared in the literature. (Hasselbalch 1916, Warburg 1922, Hastings, Sendroy & Van Slyke 1928 and Severinghaus, Stupfel & Bradley 1956). There is, however, still dis...

In a previous paper (1) the inactivation of catalase by heat at different pH was studied. It was discovered that the heat inactivation depends upon the hydrogen ion concentration of the enzyme solution which affects both the velocity and the extent of the reaction. It was also found there that 65” was the critical temperature for the enzyme preparation since at this temperature the catalase was...

IN a recent paper [1932] the writer presented data upon the rate of formation of enterokinase from its precursor in the pancreas. It was found that the observed rate conforms to the unimolecular expression and that it is a function of the hydrogen ion concentration of the medium, exhibiting a maximum at about PH 6-90. Certain additional experiments which have been carried out are now described....