CONTRIBUTION TO THE STUDY OF THE PRECIPITATION OF CARBONATES, BORATES, SILICATES AND ARSENATES

1941 ◽  
Vol 19b (8) ◽  
pp. 179-204 ◽  
Author(s):  
Paul E. Gagnon ◽  
Louis Cloutier ◽  
R. Martineau
Keyword(s):  
Liquid Medium ◽  
Room Temperature ◽  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Molar Ratio ◽  
Hydrogen Ion Concentration ◽  
Basic Carbonate ◽  
Series Of Experiments ◽  
Cobalt And Nickel

A study was made of the precipitation, at room temperature, of the carbonates of cadmium, cobalt, and nickel, of the chromate of beryllium, of the borates of zinc, of the silicates of copper and of the arsenates of lead. A rapid-mixing apparatus that insured that the precipitations took place in homogeneous liquid medium was used. In each series of experiments, the concentration of one reacting solution was kept constant and that of the other systematically varied. The values of the molar ratio of oxides, CdO/CO2 for example, in the precipitates were found by analysis. If they remained constant with different concentrations of reactants, a definite compound was indicated. The normal cadmium carbonate was obtained. Three definite basic compounds, not described in the literature, were prepared: a definite basic carbonate of cobalt, 5CoCO3∙Co(OH)2, and two definite basic arsenates of lead, 4Pb3(AsO4)2∙Pb(OH)2 and 9Pb3(AsO4)2∙Pb(OH)2. Dilead arsenate, PbHAsO4, was easily precipitated, but trilead arsenate, Pb3(AsO4)2, only under very specific conditions. The other precipitates were all mixtures. The influence of the hydrogen ion concentration of the solutions on the composition of the precipitates formed was determined.

Proteins in Fish Muscle.: III. Denaturation of Myosin by Freezing

1950 ◽  
Vol 7d (10) ◽  
pp. 599-607 ◽  
Author(s):  
J. M. Snow
Keyword(s):  
Physical State ◽  
Freezing Temperature ◽  
Fish Muscle ◽  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration

The myosin fraction of fish muscle is isolated from the other proteins and is used in a study of denaturation by freezing as determined by solubility changes. The effects of the physical state of the protein, the rate of freezing, and the hydrogen ion concentration have been determined. Ions and salts showed a significant effect when the freezing temperature was lower than the cryohydric points of the salts.

scholarly journals The influence of hydrogen-ion concentration upon the adsorption of weak electrolytes by pure charcoal.—Part II

1931 ◽  
Vol 133 (821) ◽  
pp. 155-161 ◽  
Keyword(s):  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Adsorption From Solutions ◽  
Ion Concentrations ◽  
Preferential Adsorption ◽  
Chemical Combination ◽  
Weak Electrolytes ◽  
Adsorption Curve

In a recent communication results were described which indicate that propionic, hexoic, and succinic acids are adsorbed by purified charcoal only as unionised molecules. There was no evidence that anions of these acids were adsorbed to any measurable extent. Thus the amount of these acids adsorbed from mixed solutions of any one acid and its sodium salt is propor­tional to the amount of unionised acid present as calculated from the known ionisation constants and the hydrogen-ion concentration of the solutions. Further work has led to the conclusion that the presence of an unionised carboxyl group is essential for adsorption to take place. On the other hand, the adsorption curve for the bases n -propylamine and n -butylamine at different hydrogen-ion concentrations did not follow the ionisation curves very closely.Strong preferential adsorption of the unionised molecule was observed but there was quite considerable adsorption from solutions of such acidity that no unionised amine could exist in them. The adsorption of both bases was found to fall off gradually and continuously with increasing acidity from p H 11 to P H 3. In view of the fact that the charcoal used in this work was Norit charcoal purified by treatment with strong halogen acids, it was thought possible that very small traces of these acids remained after the washing to which the char­coal was subjected, and that these traces of acid caused the adsorption of basic ions by direct chemical combination.

scholarly journals THE VIABILITY OF HEMOLYTIC STREPTOCOCCUS IN CERTAIN SOLUTIONS CONTAINING GELATIN

1924 ◽  
Vol 39 (6) ◽  
pp. 811-825 ◽  
Author(s):  
Frank L. Meleney ◽  
Zung-Dau Zau
Keyword(s):  
Room Temperature ◽  
Mechanical Injury ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Hemolytic Streptococcus ◽  
Lytic Action ◽  
Cent Concentration ◽  
Actual Growth ◽  
Wide Zone

1. The findings of Robertson, Sia, and Woo with regard to the preservative action of 0.1 per cent gelatin in suspending fluids for the pneumococcus have been confirmed for the streptococcus. 2. In gelatin-citrate, gelatin-Locke's, and gelatin-"20:1" solutions, the streptococcus will live for 3 days or longer at room temperature and for 12 hours or longer at incubator temperature in dilutions as high as 100 cocci per cc. 3. The gelatin in 0.1 per cent concentration maintains life at a fairly constant numerical level for from 15 to 24 hours. These fluids may therefore be used for certain quantitative biologic tests. 4. In slightly higher concentrations of gelatin, there is actual growth which suggests that even in 0.1 per cent concentrations the gelatin has a nutrient action. 5. There is also evidence that gelatin affords some protection against the mechanical injury of the dilution process. 6. The toxic action of unbalanced salts, the possible lytic action of water, and the autolytic action of the organisms themselves are all delayed by the presence of gelatin, but eventually these actions take place in the same manner that has been described before by many observers and as here observed for solutions without gelatin. 7. The life of streptococci is maintained in these gelatin solutions through a relatively wide zone of hydrogen ion concentration.

On the colorimetric determination of hydrogen-ion concentration in soils

1923 ◽  
Vol 13 (1) ◽  
pp. 69-73 ◽  
Author(s):  
C. T. Gimingham
Keyword(s):  
Colorimetric Method ◽  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Colorimetric Determination ◽  
Hydrogen Ion Concentration ◽  
Electrometric Method ◽  
Buffer Solutions ◽  
Special Apparatus

Of the two available methods for the determination of hydrogen-ion concentration, the electrometric is the more fundamental and satisfactory but it requires somewhat elaborate and expensive apparatus. The colorimetric method, on the other hand, though not lacking in difficulties if accurate results are wanted, requires no special apparatus and the actual procedure is simple. It is based on the electrometric method, and involves the use of buffer solutions of known hydrogen-ion concentration determined originally electrometrically.

PREPARATION OF GLUTENIN IN UREA SOLUTIONS

1931 ◽  
Vol 5 (3) ◽  
pp. 355-374 ◽  
Author(s):  
W. H. Cook ◽  
C. L. Alsberg
Keyword(s):  
Magnesium Sulphate ◽  
Dispersion Medium ◽  
Room Temperature ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Urea Solution ◽  
Previous Exposure ◽  
Hydrogen Ion Concentration ◽  
Nitrogen Contents ◽  
Urea Method

A new method has been developed for preparing glutenin, using concentrated urea solution as a dispersion medium. The starch is removed from the dispersion by passing it through a Sharpies supercentrifuge. The glutenin is then removed from the gliadin by precipitation: (a) by adding magnesium sulphate to about 0.17 of saturation; or (b) by adding water until the urea is diluted to about 10% concentration. Alcohol precipitation is unsatisfactory, since the glutenin loses much of its original solubility. Drying, even at room temperature, renders glutenin insoluble in 30% urea solution. Different samples of glutenin isolated by the urea method have similar amide and arginine nitrogen contents. The amount of these constituents is intermediate between the values reported for glutenin isolated from alkali, and that isolated from acid. While urea solutions denature some proteins, they affect glutenin less than dilute alkalies, as judged by the sulphydryl test, and no more than dilute acids. Neutral urea solutions permit a study of the physical properties of glutenin without previous exposure to extremes of hydrogen ion concentration. This method should be applicable to the isolation of glutenins from other seeds.

On the measurement of hydrogen-ion concentrations in soil by means of the quinhydrone electrode

1924 ◽  
Vol 14 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Einar Biilmann
Keyword(s):  
Colorimetric Method ◽  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Soil Extracts ◽  
Important Method ◽  
Ion Concentrations ◽  
Soil Mixtures

The measurement of the hydrogen-ion concentration of soils often presents great difficulties. When ordinary hydrogen electrodes are used, constant potentials are, in many cases, only obtained after hydrogen has been passed for several hours, while in many instances hydrogen electrodes cannot be used at all. The other important method of determining “pH,” the colorimetric method, can only be used in testing clear and almost colourless soil extracts, but not in testing soil mixtures.

scholarly journals THE ACID AGGLUTINATION OF PNEUMOCOCCI

1914 ◽  
Vol 19 (1) ◽  
pp. 28-37 ◽  
Author(s):  
L. J. Gillespie
Keyword(s):  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ion Concentrations ◽  
Inhibiting Action ◽  
Serological Type

Eight strains of pneumococci of serological type 1, eight strains of type 2, and eleven strains belonging to neither type have been tested by the method of acid agglutination. Strains belonging to the two typical groups have, as a rule, narrow zones of agglutination. The optimum hydrogen ion concentrations are different in the two cases. Other pneumococci have broad zones or, in a few cases, narrow zones not coincident with those occupied by the typical organisms. The agglutination of most of the pneumococci of types 1 and 2 is extremely susceptible to the inhibiting action of salts. This is not true of the other pneumococci. Old broth cultures may show an optimum hydrogen ion concentration different from that shown by young broth cultures.

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