Evaluation of Germicides by a Manometric Method.

Abstract

other feathers (Greenwood and Blyth,' Parkes and Selye"). These changes, taken in connection with the effects of hyperthyroidism reported here, suggest a relative increase in extent of the ventral field of saddle feathers grown under conditions of hypothyroidism. The appearance in the breast tracts of longer, saddle-like feathers with restricted barbulation following thyroidectomy is in all probability likewise associated (among other germinal changes) with a ventral field of greater or lesser extent. It should be a matter of considerable interest to alter experimentally the balance of other hormones in thyroidectomized birds in order to test the specificity of thyroxin in determining and maintaining the limited ventral triangle of feather germs of different tracts. PThe need for a method capable of evaluating germicides for chemotherapeutic use is universally recognized. Obviously, the first requirement is that the method should simulate as nearly as possible the conditions met in the animal body. In addition it should be relatively simple and should yield information regarding the action of the test substance on bacteria, and on animal tissues, in terms which would permit a direct comparison of the respective effects. The method of Lambert,' employed more recently by Salle,2 does not seem to fulfill these requirements, since the parasitotropic and organotropic properties of the disinfectant are tested under profoundly different conditions. Moreover, it is based on a tissue-culture technic which is time consuming and laborious.The manometric method proposed here has proved simple, rapid, and remarkably flexible. It permits the conditions of testing to be modified at will, and at the same time allows wide latitude in the 5Greenwood,

The Mode of Action of the Sulfonamides

“…The first material discovered to have sulfonamide-antagonistic properties was peptone (15,91,157,177,205). 23 Lockwood and Lynch (159) showed that this phenomenon is general, peptone being antagonistic to SA, SP, and ST in the case of pneumococci, staphylococci, colon bacilli and hemolytic streptococci. According to Lockwood (157), bacteria under the influence of sulfonamide are unable to break down complex protein but are still able to utilize for growth simple protein-split products, such as peptone.…”

Rapid Method for Determining Mildew Susceptibility of Materials and Disinfecting Activity of Compounds

“…This is the basic difference between this method and those manometric methods previously proposed [ 1,4,6] , which involve a measurement of the effect of a particular substance upon the respiration of a given quantity of organisms. A basic shortcoming of such techniques is that growth can be inhibited by concentrations of substances which may have little or no effect upon the immediate respiration.…”

A photometric method for the comparative evaluation of disinfectants

“…Within recent years a different approach to the problem of disinfectant standardization has been suggested by the work of Bronfenbrenner, Hershey & Doubly (1938a, b, 1939, by Ely (1939) and by Greig & Hoogerheide (1941) with proposals based on the use of respiratory methods, but their methods do not appear to have received any general acceptance, presumably owing to the inherent complexities of manometric measurements. The technique to be described in this paper originated in an attempt to overcome the defects which had been encountered in the continuous use of the accepted methods.…”