Official Circular 198 (Ruehle and Brewer, 1931) gives directions for performing the agar cup-plate test. However, in the limited literature dealing with the subject, no mention is made of the influence of varying the volume of agar, the amount of inoculum, the hydrogen ion concentration or other factors. In the course of other studies with the agar cup-plate method (Rose and Miller, 1939; Mille...

in concentration of hydrogen peroxide, first, the solution should be quite pure, and then, it concentrate with methods such as vacuum distillation and cooling crystallization, because impurities in the hydrogen peroxide solution in high concentrations are causing decomposition of this substance; that is very dangerous. the purpose of this article is separation of chromium and magnesium cations ...

1. The hydrolysis of gelatin at a constant hydrogen ion concentration follows the course of a monomolecular reaction for about one-third of the reaction. 2. If the hydrogen ion concentration is not kept constant the amount of hydrolysis in certain ranges of acidity is proportional to the square root of the time (Schütz's rule). 3. The velocity of hydrolysis in strongly acid solution (pH less th...