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The Reflecting And The Absorbing Power Of A Photographic Emulsion, P. S. Helmick

Proceedings of the Iowa Academy of Science

Measurements have been made upon the reflecting and the absorbing power of silver bromide emulsion with wave-lengths between 2100A and 5782A. The reflecting power of silver bromide emulsion averages about 7 per cent for the region 2100A to 5200A. A thickness of emulsion (0.021 mm) as found in a commercial photographic film absorbs about 96 per cent of incident radiation between 5218A and 5782A, and more than 99.99 per cent of radiation whose wave-length is less than 3247 A. From 5782A to at least 2294A the gelatine in a photographic emulsion has a negligible absorption as compared with the absorption …

A New Apparatus For Measuring Deep Water Temperatures, Frank A. Stromsten

Proceedings of the Iowa Academy of Science

There has always been a certain fascination in the study of things related to great bodies of water. The curiosity to know what is going on beneath the turbulent waves when the storm is raging and what the conditions are beneath the smooth surface when all is quiet has ever challenged our spirit of investigation. What are the environmental conditions of aquatic life has given considerable impetus to the physical and chemical phases of limnology. Temperature seems so closely interwoven into the environmental complex that careful and exact measurement of this factor is one of the first things to be …

The Banana Snake Boa Imperator, J. E. Guthrie

Proceedings of the Iowa Academy of Science

The snakes of the family Boidae are mainly confined to tropical countries in their distribution. There are two subfamilies, the true Boas and the Pythons; of which the Boas belong to the Western Hemisphere and the Pythons almost exclusively to the Old World-a single species of the latter being found in Mexico. Of the true Boas, only four species are known to occur in North America, and these are all small. One of these species is found in the states of the Pacific Coast, ranging from Washington southward. It is known as the "Rubber Boa" and seems to be a …

Some Polypores In Henry County, Mary Carnahan

Proceedings of the Iowa Academy of Science

The polypores, commonly called Bracket Fungi, are woody or tough and in the forms of brackets of various shapes and sizes. There are three classes of fungi, the third being the Basidiomycetes. Under this class there is a subclass, the Eubasidii, which contains the order Agaricales and the family Polyporaceae. Several months as occasion afforded were spent in collecting polypores in Henry County, Iowa, within a ten mile radius of Mt. Pleasant.

A Simple High Frequency Alternator, C. J. Lapp

Proceedings of the Iowa Academy of Science

High frequency alternating currents are receiving more attention in physics than ever before. Most of the recent high frequency generating devices have employed vacuum tubes. There are lines of research, however, where mechanical generators are desired.

Some Food Reactions Of Snails, E. W. Johns

Proceedings of the Iowa Academy of Science

The following work was done at the University of Chicago Zoological Laboratory under the supervision of Dr. W. J. Crozier to investigate primarily the method of innervation of the food reflex. For the studies, various forms of common snails were experimented with, but the domestic snail known as the Singapore was used for most of this work because of its ready availability and suitableness for the work due to its large size, activity and omniverousness. The main objection to them is that they do not swim on the surface of the water as do many forms. In order to obviate …

Substances Dissolved In Rain And Snow, H. S. Fries, Nicholas Knight

Proceedings of the Iowa Academy of Science

Considerable interest has been shown throughout the country on the determination of the character and quantity of substances dissolved in rain and snow. The accompanying article is a continuation of the record of the analyses of rain and snow which have been carried on at Cornell College for a number of years.

The Alumni News Letter, V7n1, January 1, 1923, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

In Memoriam: Gustavus Detlef Hinrichs; James Edward Todd, Charles Keyes

Proceedings of the Iowa Academy of Science

No abstract provided.

The Role Of The Vagi Of Gastric Motility In Necturus Maculatus, T. L. Patterson

Proceedings of the Iowa Academy of Science

Previous work on the movements of the empty stomach of the Necturus has indicated that the controlling influence of the vagi is largely inhibitory. This phenomenon is contrary to that which exists in the stomachs of higher animals, although it has been shown by Hopf for the frog and by Bercovitz and Rogers for the turtle that the tenth nerve contains both motor and inhibitory nerve fibres to the stomach with the motor predominating, at least in the frog.

Some Conditions Affecting Tree Growth As Revealed By The Annual Rings, Max W. Van Horn

Proceedings of the Iowa Academy of Science

The stump which is left when a tree is cut reveals a number of things about its rate of growth and the conditions which have affected its development. During the fall of 1922 and the spring of 1923 the writer measured the surfaces of a number of these and counted their annual rings for the purpose of comparison, and to discover, if possible, some conditions governing their growth rates.

An Instance Of Polymely In The Frog, Albert Kuntz

Proceedings of the Iowa Academy of Science

In November, 1922, a polymelous specimen of Rana clamata was brought into the laboratory by one of my students who informed me that it was found on the grounds of his home in the city in a pool which had been stocked with frogs' eggs which were collected in the environs of St. Louis in the spring of 1921.

What Is The Relation Between The Moisture Content And Viability Of Seed Corn When Subjected To Low Temperatures?, Winfield Scott

Proceedings of the Iowa Academy of Science

Farmers have long known that a light freeze early in the fall is likely to injure the corn crop for seed purposes the following year. The crop of 1917 was thus severely injured and much labor and money were expended to secure even fair seed for the planting in 1918. While the experiment as planned does not compare fully with conditions as they are in fields of maturing corn, it was begun with the idea of giving some information on the vitality of seed corn after having been frozen. To be satisfactory more work should be done using various moisture …

Synthetic Hypnotics In The Barbituric Acid Series, Arthur W. Dox

Proceedings of the Iowa Academy of Science

The increasing demand for sleep-producing drugs is perhaps one of the characteristics of the restless age in which we now live. Not a year passes but half a dozen new synthetic hypnotics appear in the patent literature and a few of these find their way into the drug market. Most of these fail to meet the claims made by the manufacturers and are soon discarded, and the physicians continue to prescribe the eight or ten more or less familiar drugs that have survived several decades of clinical experience. Meanwhile, the chemical and pharmaceutical laboratories continue their search for the ideal …

Some Large Colonies Of Stromatopora Found Near Iowa City, Iowa, A. O. Thomas

Proceedings of the Iowa Academy of Science

The River Products Company of Iowa City recently opened a quarry for crushed stone on the right bank of Iowa river in section 33, township 80 north, range six west. This locality is about one and a quarter miles northeast of Coralville and close to two miles northwest of Iowa City. The rock used is Cedar Valley limestone and the stone is overlain by a few feet of mantle rock largely of glacial origin. The face of the west end of the quarry at the time the first specimens were obtained was a little over fifteen feet high and its …

A Day Near Muskogee, Oklahoma, L. H. Pammel

Proceedings of the Iowa Academy of Science

In 1921 the writer spent a short time in a study of some of the interesting plants found near Muskogee, Oklahoma. It may be observed here that there have been some very remarkable changes in the region. The writer's first acquaintance with the place was in 1888 when it was only one of the numerous small villages on the line of the Missouri, Kansas & Texas R. R. In 1870 it was the chief town of the Creek nation and now is the administrative center of the five civilized tribes of Indians, with a population of over 50,000. The town …

The Address Of The President - Botanical Notes On Fiji And New Zealand, Robert B. Wylie

Proceedings of the Iowa Academy of Science

Botanical notes on Fiji-An expedition to Fiji and New Zealand, which occupied the summer vacation of 1922, was joined by the writer in the hope of furthering certain long desired ends. As a teacher he was anxious to experience contact with those remote regions and to observe the plants and conditions of the great middle zone. Opportunity was desired also for the collection of class room and research material not available in the temperate regions. If only one other of several objectives is named it should be the desire to see something of the economic plants and agricultural conditions in …

A Calculation Of The Bulk Modulus Of The Earth, L. P. Sieg

Proceedings of the Iowa Academy of Science

The following simple calculation is by no means intended to be an exhaustive investigation of the volume elasticity of the earth. Granting the postulates laid down, it is a definite problem, and the solution seems to be definite and exact. Without doubt the actual problem is vastly more complicated than the present discussion would indicate.

The 1918 Outbreak Of Sod Webworms In Iowa, R. L. Webster

Proceedings of the Iowa Academy of Science

Early in 1918 reports began to come in to the Iowa Experiment Station of damage to bluegrass pastures by sod webworms. The first reports were from the extreme southwestern part of the state. These records were made either by correspondents, or by two field agents of the federal Bureau of Entomology at that time working under the writer's direction in the state.

An Excellent Example Of High Clay Bank Erosion In Lee County, Iowa, Ben H. Wilson

Proceedings of the Iowa Academy of Science

There are at least two pre-glacial valleys in Lee County, which is situated in the extreme southeast corner of the state of Iowa, the first running nearly parallel to the present course of the Mississippi, and the other roughly parallel with the valley of the Des Moines. These valleys were once occupied by great mid-continental streams, whose geological age has never been fully determined. Their waters eroded channels several miles in width through the indurated rocks of the Carboniferous, over which they passed, to a depth considerably below the present grade of the water courses with which they are analogous.

The Geographic Distribution Of Iowa Devonian Echinoderms, A. O. Thomas

Proceedings of the Iowa Academy of Science

In connection with a paper recently prepared for the Iowa Geological Survey, entitled "Echinoderms of the Iowa Devonian," some interesting facts regarding the geographic distribution of the echinoderms of this system were ascertained. Forty-three species and two varieties constitute the total number studied. Of these four are cystids, four are blastoids, thirty are crinoids, and five are echinoids. The two varieties consist of one camerate crinoid and one echinoid. Seven of the species are known to occur in the Devonian of neighboring states.

The "K" And "L" X-Ray Spectra Of Tungsten, Charles B. Crofutt

Proceedings of the Iowa Academy of Science

This paper is a partial report on the complete investigation of the x-ray spectra of tungsten, both emission and absorption. It deals only with the emission and absorption spectra of the "K" and "L" regions. The "M" region is being investigated by Mr. R. V. Zumstein. The x-ray spectrum of tungsten has been the most extensively investigated of any element. However the work has been done at different times by experimenters using different apparatus and methods. For this reason it seemed advisable to make a complete investigation using as near as possible the same apparatus and conditions throughout.

Notes On The Occurrence Of A Black Bituminous Shale Near Palo, Linn County, Iowa, Glenn S. Dille

Proceedings of the Iowa Academy of Science

The rock formations of Linn County belong to the Devonian period. During an examination with the possible exploitation of Devonian rock as a source of Portland Cement, Mr. A. S. Hammond and others of Cedar Rapids, Iowa, encountered in an excavation near Palo, Iowa, a black, bituminous shale. The shale is fine-grained and in places very bituminous. The layers vary in thickness from mere seams along bedding planes to an inch in thickness where exposed in the excavation, and lie at various depths below the surface in the valley of Little Bear creek. The presence of an old shaft …

Production Of High Amperage In Low Voltage Coolidge Tube, R. V. Zumstein

Proceedings of the Iowa Academy of Science

In a Coolidge tube, the electrons are focused upon the target by a metal tube surrounding the filament. As this tube projects more and more beyond the filament the electrons come to a smaller and smaller focal spot. The magnitude of the electronic current from the filament increases slightly as the voltage is increased, but it increases very rapidly as the filament is made hotter. As the filament is heated still hotter the electronic current does not increase toward infinity but attains a maximum value. This saturation value may be as low as 40 mili-amperes.

The Light-Energy Of 2536a Required To Render Developable A Grain Of Silver Bromide, P. S. Helmick

Proceedings of the Iowa Academy of Science

A photographic film was exposed to a measured quantity of monochromatic light-energy at 2536A, and the resulting number of silver bromide grains rendered developable by the exposure was determined by a direct microscopic count. It was thus possible to calculate the energy required to render developable a single grain of silver bromide. A mercury arc and an ultra-violet monochromator provided the monochromatic light-energy. Quantitative measurements of light-energy were made with a linear thermopile in combination with a Thomson galvanometer of figure of merit 4 X 10^-10 amp/mm. One candle-meter on the thermopile gave a galvanometer deflection of 1500 mm. …

Polygonum In The State Of Iowa, G. L. Wittrock

Proceedings of the Iowa Academy of Science

The Polygonums have been reviewed with the view to find out their occurrence and distribution in the state of Iowa. Twenty species are found in the state. Grateful acknowledgment is made to Dr. L. H. Pammel and Mr. R. I. Cratty of the State College at Ames, and to Professors Shimek and Wylie of Iowa City, for the use of their herbarium collections. In the following lists, the paper shows Polygonum as represented in the Grinnell herbarium and the two main herbaria of the State.

Some Fossils From An Outcrop In Des Moines, A. O. Thomas

Proceedings of the Iowa Academy of Science

At the time of the meeting of the Iowa Academy of Science at Drake University, Des Moines, in April, 1922, the writer accompanied by Mr. Ben Hur Wilson made a brief visit to the clay pit of the Capital City Clay Company. This pit is located along the Chicago Great Western railroad tracks south of Raccoon river in the city of Des Moines and while perhaps the most extensive, is typical of similar exposures in the city. About thirty-five to forty feet of bluish shale and a few thin beds of sandstone and sandy shale are exposed and worked for …

College Circular [Catalog] 1923, Iowa State Teachers College

UNI Programs and Courses Catalogs

Table of Contents

Calendar for 1923-24 ... 5
Officers of Administration and Instruction ... 6
General Information ... 35
Residence, Student Health, Assembly ... 36
Expenses and Fees ... 36
Free Scholarships ... 38
Extension Service ... 38
College Organizations ... 39
Faculty Organizations ... 40
Training in Actual Teaching ... 40
Public Lectures and Entertainments ... 41
Boarding and Lodging ... 41
Employment of Students ... 42
Twelve Weeks Normal Training ... 42
School Credits in Lieu of Certificate Examinations ... 43
Examinations for Teachers Certificates ... 43
Department Certificates ... 44
Bureau of Recommendations ... 44
Advisers and …

An Extension Of Acoustic Wave Filter Theory, G. W. Stewart

Proceedings of the Iowa Academy of Science

It was anticipated that if acoustic filters were used at frequencies whose wave lengths were comparable to the length of the acoustic conduit of one section, thus violating one of the assumptions of the original theory, the computations concerning attenuation would be incorrect and that, indeed, transmission would occur at frequencies where the simple theory would specify high attenuation. This is found to be the case with the low-frequency-pass and single band filters previously described. In both cases a series of bands are transmitted at higher frequencies. It is now found that if the conduit at these higher frequencies is …

New Vibrations Within A Conical Horn, Victor A. Hoersch

Proceedings of the Iowa Academy of Science

In the case of simple harmonic motion, the time factor being e^iσt, the velocity potential Φ of the vibrations must satisfy the equation (Δ² + k²) Φ = 0. Where k = σ /c in which c is the velocity of sound.