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Gastric Motility In Vitamin Deficiency, Erma Anita Smith Jan 1927

Gastric Motility In Vitamin Deficiency, Erma Anita Smith

Proceedings of the Iowa Academy of Science

Guinea pigs in vitamin C deficiency and dogs in vitamin B deficiency were studied.

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The Significance Of The Hydrogen-Ion Concentration In Soil Nitrification Studies, Harry Humfeld, Lewis W. Erdman Jan 1927

The Significance Of The Hydrogen-Ion Concentration In Soil Nitrification Studies, Harry Humfeld, Lewis W. Erdman

Proceedings of the Iowa Academy of Science

Although considerable work has been reported in the literature which shows some correlation between nitrification and the crop-producing power of soils, very little attention has been given to the significance of the soil reaction in nitrification studies. The object of this paper is to consider this problem and data are presented which show the relation of the reaction of the soil or its hydrogen-ion concentration to its nitrifying capacity.

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The Synthesis Of Vitamins By Microorganisms, Gertrude Sunderlin, C. H. Werkman Jan 1927

The Synthesis Of Vitamins By Microorganisms, Gertrude Sunderlin, C. H. Werkman

Proceedings of the Iowa Academy of Science

The synthesis of vitamin B is of general occurrence among microorganisms. Negative results of some investigators may be accounted for by inadequate amounts fed or too limited feeding periods. Our experiments showed the following organisms to elaborate vitamin B when tested by the rat weight test: Saccharomyces cerevisiae, Torula rosea, Oospora lactis, Bacillus adhaerens, Bacterium coli (three strains), Bacillus subtilis and Bacillus mycoides.

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The Influence Of The Size Of Retinal Image And Of Perspective Upon The Visual Perception Of Distance: A Comparative Study, Ruth Updegraff Jan 1927

The Influence Of The Size Of Retinal Image And Of Perspective Upon The Visual Perception Of Distance: A Comparative Study, Ruth Updegraff

Proceedings of the Iowa Academy of Science

Upon the assumption that visual perceptions are integrated in character and that some kind of an empirical basis is presupposed in their formation, we have attempted to segregate, for experimental purposes, two of the more commonly acknowledged factors in the estimation of relative distances. Both of these factors may be said to be functions of the stimulus, rather than of the response. A comparison of their relative influence in the distance perceptions of young children and adults, as well as a study of acuity in these perceptions, is the object of this investigation.

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Table Of Contents Jan 1927

Table Of Contents

Proceedings of the Iowa Academy of Science

No abstract provided.

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Proceedings Of The Forty-First Annual Meeting Of The Iowa Academy Of Science, Held At Iowa City, May 6 And 7, 1927: Minutes Of The Meeting; Staff & Committee Reports Jan 1927

Proceedings Of The Forty-First Annual Meeting Of The Iowa Academy Of Science, Held At Iowa City, May 6 And 7, 1927: Minutes Of The Meeting; Staff & Committee Reports

Proceedings of the Iowa Academy of Science

No abstract provided.

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Occurrence Of The Various Groups Of Legume Bacteria In Iowa Soils, Lewis W. Erdman, Rudger H. Walker Jan 1927

Occurrence Of The Various Groups Of Legume Bacteria In Iowa Soils, Lewis W. Erdman, Rudger H. Walker

Proceedings of the Iowa Academy of Science

For a long time it has been known that the root-nodule bacteria of the Leguminosae differ considerably in their ability to inoculate plants. An outstanding example of this fact was brought to the attention of the early investigators when it was found that soybeans failed to produce nodules in European soils, while many other species of legumes were naturally inoculated. Kirchner (4), the first investigator to inoculate soybeans in Germany, found that it was necessary to use soil from Japan where the soybean was native and naturally inoculated. Since that time many such examples have been recorded. Just recently Gangulee …

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A Simple And Effective Method Of Detecting Trichina In Sausage, C. S. Linton Jan 1927

A Simple And Effective Method Of Detecting Trichina In Sausage, C. S. Linton

Proceedings of the Iowa Academy of Science

Trichinosis is not a common disease in the United States on account of present day methods of handling meats and the rather universal habit of eating meat only after being well cooked. Occasionally, however, we find people partaking of raw or poorly cooked sausage. An outbreak of the disease resulting from the eating of raw "summer sausage" and involving five or six families and ten or more individuals occurred at Bridgewater, Iowa, last February. Several of the cases proved fatal.

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Agglutination And Colloidal Reactions, F. W. Mulsow Jan 1927

Agglutination And Colloidal Reactions, F. W. Mulsow

Proceedings of the Iowa Academy of Science

Many theories have been advanced in explaining the cause of the clumping and precipitation of bacteria by their immune serum. It is generally known that the presence of salt solution is also necessary. In many text books of bacteriology the statement is made that acids and alkalis inhibit the agglutination reaction, but amounts necessary to do this are not given. It has been observed in the present work that alkalis have a stronger inhibiting action than acids. Ammonium hydroxide has very little effect as compared to sodium or potassium hydroxide. The weak acids however have as strong an inhibiting action …

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Microbiological Death Rates, C. H. Werkman Jan 1927

Microbiological Death Rates, C. H. Werkman

Proceedings of the Iowa Academy of Science

The form of the survivors' curve when Staph. aureus is subjected to the action of bactericides is not constant. It is a function of the organism and the specific bactericide and attempts to conform such curves to one generalized formula, monomolecular or polymolecular, must prove futile. Under identical conditions the survivors' curves are alike in form.

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Relative Costs Of Home Made And Dehydrated Nutrient Agar, Max Levine Jan 1927

Relative Costs Of Home Made And Dehydrated Nutrient Agar, Max Levine

Proceedings of the Iowa Academy of Science

Batches of 1, 4, and 7 liters of nutrient agar were prepared from the ingredients according to Standard Methods, and the costs compared with those of similar batches made from commercial dehydrated nutrient agar. The costs of ingredients, labor, and loss due to filtration, were the only items considered.

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Bacterial Blackening Of Canned Vegetables, C. H. Werkman, Helen Weaver Jan 1927

Bacterial Blackening Of Canned Vegetables, C. H. Werkman, Helen Weaver

Proceedings of the Iowa Academy of Science

"Sulfur stinker" is the trade name given to canned sweet corn which has undergone an anaerobic decomposition resulting in a blackened condition of the germ, and the evolution of hydrogen sulfid gas. The condition is caused by an anaerobic, gram positive, sporulating, hydrogen sulfid producing thermophile whose spores resist boiling temperature for five hours. Vegetative cells are destroyed by 10 min. at 100°C. Optimum temperature for multiplication is 55°C.; the upper limit is 65°C. Growth and blackening of corn occur at room temperature if incubation is sufficiently long - 6-8 weeks. The organism occurs singly or in chains of as …

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A Brief Summary Of Work On Iowa Algae, G. W. Prescott Jan 1927

A Brief Summary Of Work On Iowa Algae, G. W. Prescott

Proceedings of the Iowa Academy of Science

My part in the taxonomic survey of the algal flora of Iowa began in the fall of 1924. It may be of interest at this time to summarize briefly the work done on the algae of Iowa, including my unpublished notes.

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Preliminary Report On Amino Acid Synthesis In Plants, Walter F. Loehwing Jan 1927

Preliminary Report On Amino Acid Synthesis In Plants, Walter F. Loehwing

Proceedings of the Iowa Academy of Science

The process of amino acid synthesis in plants involves essentially a reduction of nitrates absorbed from the soil. It is difficult, however, to distinguish newly synthesized amino acids from those originating as hydrolytic cleavage products of proteins. To circumvent this difficulty, earlier investigators (2, 5, 6, 8), exposed their plants to nitrogen starvation, thereby reducing soluble nitrogen compounds in tissues to a minimum. Unfortunately, it is extremely difficult to remove final traces of nitrates and ammonia by starvation without causing high mortality in experimental material, and pathological conditions in many of the plants which do survive this rigorous treatment.

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The History And Distribution Of Yellow Nelumbo, Water Chinquapin, Or American Lotus, Mrs. H. J. Taylor Jan 1927

The History And Distribution Of Yellow Nelumbo, Water Chinquapin, Or American Lotus, Mrs. H. J. Taylor

Proceedings of the Iowa Academy of Science

Much interest has been manifested in recent years in the American lotus, not only because of the economic value but its value for ornamental purpose and its beauty in its native habitat.

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Flowering Plants Of Henry County, Iowa - Ii, J. M. Lindly Jan 1927

Flowering Plants Of Henry County, Iowa - Ii, J. M. Lindly

Proceedings of the Iowa Academy of Science

In the Proceedings of the Iowa Academy of Science for the year of 1904, Volume XII, page 157, will be found the first installment of the flowering plants of Henry County as identified by the writer during the earlier years of the decade of the nineties. The second installment from this list is submitted herewith. The third installment will be found in a later issue of the proceedings of the Academy.

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Notes On Iowa Fungi - 1926, G. W. Martin Jan 1927

Notes On Iowa Fungi - 1926, G. W. Martin

Proceedings of the Iowa Academy of Science

This handsome mushroom was described from New York in 1872 by Peck1 as Agaricus (Amanita) volvatus. It is not uncommon in the eastern United States, and Murrill2 noted that it occurs rarely in the warmer parts of temperate Europe. By most recent writers it is placed in the genus Amanitopsis, or its equivalent, Vaginata. Thus Kauffman3 lists it as Amanitopsis volvata Pk.; Coker4 as Amanitopsis agglutinata (B. & C.) Sacc.; Murrill5 as Vaginata agglutinata (B. & C.) Kuntze. On the other hand, J. E. Gilbert6 regards it as identical with Amanita avoidea Bull. var. …

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Some Physico-Chemical Effects Of Organic Soil Colloids, Walter F. Loehwing Jan 1927

Some Physico-Chemical Effects Of Organic Soil Colloids, Walter F. Loehwing

Proceedings of the Iowa Academy of Science

An investigation was undertaken to determine the reason for injurious effects of lime to grains grown on certain acid organic soils which occur in the Great Lakes region. Analyses were made of the soils (table I) and crops (table II) in order to determine if a harmful physical change occurred in the soils after liming or if lime was chemically injurious. The organic soils studied were black, powdery, acid and deficient in potash as shown by the soil analyses. Crop injury following use of lime to correct acidity in these soils is an unexpected response which occurs frequently enough to …

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Weeds Of California And Their Relation To Weeds In Other Sections Of Country, L. H. Pammel Jan 1927

Weeds Of California And Their Relation To Weeds In Other Sections Of Country, L. H. Pammel

Proceedings of the Iowa Academy of Science

The subject of weeds, no matter where they occur, is always of perennial interest. They travel apparently from one end of the country to the other. Sometimes they become permanent and sometimes are only transient. Sometimes they persist for a few years and then disappear; of this Lactuca scariola L. and its variety is an illustration.

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The Physiographic Ecology Of A Wisconsin Drift Lake, Lois A. Catlin, Ada Hayden Jan 1927

The Physiographic Ecology Of A Wisconsin Drift Lake, Lois A. Catlin, Ada Hayden

Proceedings of the Iowa Academy of Science

In Iowa, practically all of the swamp land and many of the smaller lakes with which the early pioneers were familiar have been drained and there agricultural crops are grown. Whether the greatest economic benefit may be derived from appropriating for agricultural purposes such a small proportion of the land as lake beds represent, or by conserving and developing their natural resources is a subject for consideration. With one exception (that of Wall Lake in Wright County), Little Wall Lake is the only lake of any size within an area with radius of at least fifty miles, and in view …

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Manganese In Iowa City Waters, Edward Bartow, W. T. Bailey Jan 1927

Manganese In Iowa City Waters, Edward Bartow, W. T. Bailey

Proceedings of the Iowa Academy of Science

More than thirty years ago Proskauer reported the presence of manganese in many ground waters. For a long time afterward little attention was paid to the subject because it had not been proved that manganese imparted any bad qualities to water. But in 1906, the sudden appearance of iron and manganese in the Breslau water supply (1) in such quantities as to cause it to be abandoned, forced the recognition of the fact that iron and manganese produce like qualities in water. The first water in this country in which manganese occurred in sufficient quantity to cause trouble was from …

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The Adsorption Of Certain Vapors By Charcoal At Various Temperatures Up To And Above Their Critical Temperatures, J. N. Pearce, C. M. Knudson Jan 1927

The Adsorption Of Certain Vapors By Charcoal At Various Temperatures Up To And Above Their Critical Temperatures, J. N. Pearce, C. M. Knudson

Proceedings of the Iowa Academy of Science

It is perhaps safe to state that no one property of a solid substance has been more persistently studied through so long a period as has been the property of solid porous bodies to adsorb gases and vapors. The phenomenon of the adsorption of gases and vapors by charcoal was originally discovered independently by Scheele1 and by Fontana1 in 1777. In the century following much was contributed which deals with the general qualitative side of adsorption. It was not until the beginning of the present century and more particularly with the advent of poison gas warfare and the …

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The Rate Of Evaporation Through Surface Films, Raymond Bartlett, Thos. C. Poulter Jan 1927

The Rate Of Evaporation Through Surface Films, Raymond Bartlett, Thos. C. Poulter

Proceedings of the Iowa Academy of Science

The purpose of this investigation was to study the influence of surface tension on the rate of evaporation of water through surface films. We determined the rate of evaporation of pure water and water from solutions of calcium and sodium chlorides of concentrations varying from zero to nearly saturation.

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The Commercial Preparation Of Oxygen From Lime And Chlorine, O. R. Sweeney, A. W. Ralston Jan 1927

The Commercial Preparation Of Oxygen From Lime And Chlorine, O. R. Sweeney, A. W. Ralston

Proceedings of the Iowa Academy of Science

The reaction of chlorine on a suspension of lime in the presence of suitable catalysts, such as nickel, cobalt and iron salts, has been studied. It was found that the optimum temperature is 94° C.; that the greatest unit efficiency of the catalyst, nickel nitrate, is obtained at a concentration of.02 g. per 100 c.c; that the rate of generation of oxygen is almost directly proportional to the rate of flow of the chlorine and that nickel and cobalt salts are distinctly superior to all other catalysts which were used. In addition it has been found that the catalyst is …

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A Study Of The Reactions Involved In A System Of Zn And H2so4 Under Pressures Up To 16,000 Atmospheres, Thos. C. Poulter, Glen E. Frazer Jan 1927

A Study Of The Reactions Involved In A System Of Zn And H2so4 Under Pressures Up To 16,000 Atmospheres, Thos. C. Poulter, Glen E. Frazer

Proceedings of the Iowa Academy of Science

A continuation of the investigation described in the previous paper. A method is described for following the rate of the reaction at very high pressures in which the pressure can be varied rapidly and the rate of the reaction continuously read. Very little effect upon the rate of the reaction, directly due to pressure, was noticed up to pressures of 6000 atmospheres. The pressure cells used for this work were exhibited including one that was ruptured at a very high pressure.

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Heat Of Adsorption On Charcoal Of Certain Organic Vapors, Lloyd Mckinley, J. N. Pearce Jan 1927

Heat Of Adsorption On Charcoal Of Certain Organic Vapors, Lloyd Mckinley, J. N. Pearce

Proceedings of the Iowa Academy of Science

Previous work on the heat of adsorption has been carried out by the use of the ice calorimeter adapted only to those liquids of appreciable vapor pressure at 0°C., and affording no investigation of the effect of temperature upon the heat of adsorption. In the present paper there is described a method for studying the heat of adsorption at different temperatures by employing a sensitive thermo-couple in a calorimeter system consisting of a known weight of low specific heat oil in a Dewar flask. With this arrangement we find that a change of 1 microvolt in the thermocouple reading corresponds …

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Solubility Of Copper In Milk, E. I. Soloman, G. N. Quam Jan 1927

Solubility Of Copper In Milk, E. I. Soloman, G. N. Quam

Proceedings of the Iowa Academy of Science

The solubilities of copper in sweet whole raw milk held at a constant temperature for 30 minutes were determined for temperatures ranging from 20 degrees Centegrade to 100 degrees Centegrade. Copper sheets of known dimension were totally immersed and agitated in milk for 30 minutes at the specified temperature. Solubility values were determined by difference in weight of the copper sheets and also by determining colorimetrically with potassium ethyl xanthate the copper present in the ash of the milk. Solubilities per unit area increase with rise in temperature up to 80 degrees Centegrade.

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A Study Of The Potentials And The Activities Of The Metals In Zinc Amalgam Cells, J. N. Pearce, J. F. Eversole Jan 1927

A Study Of The Potentials And The Activities Of The Metals In Zinc Amalgam Cells, J. N. Pearce, J. F. Eversole

Proceedings of the Iowa Academy of Science

The electromotive forces of cells containing zinc amalgam electrodes in a saturated solution of zinc sulphate, have been determined at 18°, 25 ° and 30°. The concentration of the zinc in the amalgams varied from N = 0.000302 to that of a two-phase amalgam, N = 0.0638.

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The Influence Of Solvent Upon The Optical Rotation Of Di-Ethyl Tartrate, T. J. Herbert, J. N. Pearce Jan 1927

The Influence Of Solvent Upon The Optical Rotation Of Di-Ethyl Tartrate, T. J. Herbert, J. N. Pearce

Proceedings of the Iowa Academy of Science

A determination of the specific rotation of di-ethyl tartrate in various mixed-solvents has been made at 25° and 30°, using two different concentrations of the ester. The solvents used were ethyl alcohol, methyl alcohol, benzene and toluene and the binary mixtures of each solvent with each of the remaining solvents. The mixed solvents were made on a mol fraction basis.

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The Newly Completed Waterworks Of The City Of Oneida, New York, Nicholas Knight Jan 1927

The Newly Completed Waterworks Of The City Of Oneida, New York, Nicholas Knight

Proceedings of the Iowa Academy of Science

The supply comes from Florence Creek, 22 miles north of the city. A 20-inch main conveys the water. The watershed contains 17 square miles, very sparsely settled and the danger from contamination is slight. There is an unusual amount of precipitation in that section of New York State, and in the dryest year of recent times, the rainfall was 41.28 inches.

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