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From the early 17th century the advent of physical and chemical sciences developed two important movements toward the explanation of all vital phenomena: the Iatrochemical and Iatromechanical Schools. The important research of their representatives such as Jan Baptist van Helmont, John Mayow, Robert Boyle, Gian Alfonso Borelli, Richard Lower, and Albrecht von Haller, followed by the discovery of the atmospheric gases, provided a fecund soil for the leading work of Lavoisier in respiratory physiology.

The phenomena of stable and transient acoustic cavitation in liquids exposed to ultrasound are briefly explained. The role of micronuclei, resonant bubble size, and rectified diffusion in the initiation of transient cavitation is reviewed. In aqueous solutions transient cavitation initially generates hydrogen atoms and hydroxyl radicals that may recombine to form hydrogen and H2O2 or may react with solutes in the gas phase, at the gas-liquid boundary, or in the bulk of the solution. The analogies and differences between sonochemistry and ionizing radiation chemistry are explored. The use of spin trapping and electron spin resonance to conclusively identify hydrogen atoms and hydroxyl radicals and to detect cavitation produced by continuous wave and by pulsed ultrasound is described in detail.

In the conventional treatment of sewage, the solids are normally disposed of by anaerobic digestion. This leaves a considerable amount of plant nutrients, such as nitrogen and phosphate, as soluble compounds which will eventually find their way into the plant's final effluent, since the supernatant fluid from the digesters is normally returned to the raw sewage. In a recent investigation, we found that, if the sludges were treated by an aerobic process, a significant portion of the carbonaceous matter was oxidized to carbon dioxide and water, and the rest was assimilated into microbial protoplasm. This process tied up the available nitrogen and phosphorus so that practically none remained dissolved in the suspending liquid. The accumulated solids, consisting mostly of microbial cells, were separated very easily from the liquid, leaving a slightly colored supernatant fluid that was water-clear, free from plant nutrients, and very low in BOD and COD. The overall process was accomplished in a detention time not exceeding 20 days, in contrast to anaerobic digestion which requires from 50 to 70 days.

Georg, Lucille K. (Communicable Disease Center, Atlanta, Ga.), Gordon W. Robertstad, and Sherry A. Brinkman. Identification of species of Actinomyces. J. Bacteriol. 88:477-490. 1964.-Four unusual isolates of Actinomyces species were compared with six control strains of well-identified Actinomyces species. Their oxygen requirements and their morphological and biochemical characteristics were determined. Final identifications were confirmed by cell-wall analyses for amino acid and carbohydrate composition and by agar-gel techniques. Two strains, A-13-R and A-13-S, isolated from the same cow head were shown to represent rough and smooth variants of A. bovis. The strains were not only morphologically distinct, but had different biochemical reactions and antigenic makeup. The two other strains, X407 and X573, isolated from human pleural fluid and a lung abscess, respectively, were shown to represent a new Actinomyces species.

The oxygen-stable streptococcal hemolysins, which can be induced by a number of diverse substances, have been studied. Differences among these hemolysins have been found in electrophoresis, chromatography, pH stability, and susceptibility to some organic solvents and to an enzyme, RNAase. These properties have in each case been found to characterize the inducing substances as well. In a number of instances it has been found possible to incubate one inducer with the hemolysin induced by another of these agents and then, after appropriate fractionation, to find hemolytic activity in the fraction containing the fresh inducer. These observations suggest that the oxygen-stable streptococcal hemolysins are constituted as carrier-hemolysin complexes, the carriers being the set of molecular species effective as inducers, and the prosthetic group being transferred from one carrier to another under appropriate conditions. After transfer of the hemolytic moiety from a hemolysin molecule which is susceptible to inactivation by a given agent or set of conditions to a carrier which is not itself significantly affected by this agent, the new, derived, hemolysin has been found not to be inactivated by the agent. The hemolysins of this group can thus be inactivated by enzymatic attack on the prosthetic group, or by hydrolysis or deformation of the postulated carrier molecule.

Gamma-ray irradiation of polypeptides as highly dispersed fluffs under oxygen leads to chemical degradation of the peptide bond with the remarkably high oxygen consumption of about one molecule per 2 ev of absorbed energy. A radical chain mechanism appears to be involved, and there is evidence that excited states of the polypeptide aggregate undergo chemical quenching by molecular oxygen.

Gaseous oxygen atoms, thermally generated from O(s) on a 2300 degrees K zirconia surface, react with simple condensed olefins below 100 degrees K. Initial results indicate that the distribution of products differs from that obtained in the gas phase at higher temperatures.