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With the advent of well‐fertilized corn (Zea maysL.) raonocultures with large amounts of residues returned to the soil, the question arose as to whether organic matter could be maintained at satisfactory levels in Corn Belt soils. To answer this question changes in the amounts and composition of the soil organic matter were determined in a field experiment where different types [alfalfa (Medicago sativaL.), cornstalks, sawdust, oat straw (Avena sativaL.), and bromegras(Bromus inermisLeyss)] and amounts (from 0 to 16 tons/ha/yr) plant residues were added to Marshall silty clay loam (Typic Hapludoll) for 11 consecutive years. The soil was cropped to corn and large amounts of N fertilizer were added. Organic C, N, S, and P contents of the soils increased in proportion to the amount of plant residues added. After 11 years contents of the 0‐ to 15‐cm depth of the check plots were 1.6% C, 0.15% N, 0.023% S, and 0.018% P. Average increases over the check for C, N, S, and P were 47, 37, 45, and 14%, respectively, for the 16‐ tons/ha/yr treatment. Type of plant residue when added at 8 tons/ha/yr did not influence the C or P contents of the soils differently. The organic N and S contents, however, were lower with sawdust than with the other residues. Cumulative effects of increasing quantities of organic residues on available nutrients in the soils showed that NH4‐N production, weak‐acid‐soluble P, and exchangeable K increased significantly. The amount of cornstalk residue needed to prevent loss of organic C was estimated to be 6 t/ha/yr.

A mulch of crop residue as compared to a like amount of residue plowed into the soil significantly retarded plant growth. This retardation occurred independently of N fertility, soil moisture, and soil compaction. However, interactions between residue placement and the other variables was sometimes observed.

Early growth of corn was progressively retarded by increasing amounts of mulch.

Roots of barley (Hordeum vulgare) seedlings were allowed to grow into soil aggregates about 1 cm in diameter. The aggregates were formed to have densities ranging from 1.4 to 1.8 g cm‐3. The resulting physically different internal structures were used to vary the extent of root proliferation within the aggregate. Aggregates of different densities were mixed so that the roots had equal opportunity to grow into the various physical types of aggregates. Root growth into a given aggregate type was ascertained by tagging certain aggregates with 32P. Roots penetrated agregates having dry densities of 1.4 g cm‐3but were restricted to the periphery of aggregates having a dry density of 1.8 g cm‐3. Root growth within a given aggregate was also affected by the soil strength and pore size distribution within adjacent aggregates. Roots growing in beds of aggregates of uniform density were qualitatively, as well as quantitatively, different from roots growing in beds of aggregates with more than one density. Although not measured directly, the extent of root hair development and the soil volume explored by a given root segment in various physical environments were likely responsible for this difference in root characteristics. The relationship between these data and field observations is given.

The interactive effect of overburden pressure and root confinement on root elongation in a fine‐structured loam soil has been examined using fine‐metal probes to simulate a plant root. Substantial increases in probe resistance with simulated overburden pressure were found only at high soil bulk densities and high ratios of probe to soil volumes. These findings suggest that for low root to soil volumes (root density) and the maximum soil density used, 1.63 g cm‐3, the elongation rate of plant roots at a depth of 150 cm would be only 4% less than in the surface layer. For root densities in excess of 0.01 and the same bulk density and depth of overburden, the model predicts a 30% reduction in elongation rate.

A method is described for measuring axial strain in a remolded loam soil under unconfined axial loading in both compression and tension. Using this method the stress‐strain relationships for the loam soil were determined for soil‐water contents ranging from 2% to 12% by weight. The maximum tensile stress in a soil beam stressed to failure in a modulus of rupture test was computed from the measured stress‐strain relationships. This computed fiber stress was approximately 10% greater than the measured tensile strength. The strain energy required to rupture this soil in axial tension, taken as the area under the stress‐strain curve, was shown to increase by only 20% for a sixfold increase in tensile strength and to be almost proportionately related to the energy required to produce a fixed degree of soil breakup in a drop‐shatter test.

In a previous paper1 we called attention to the fact that the blood serums of children consuming milk from cattle infected with contagious abortion often contain antibodies against Bacillus abortus.Contagious abortion of cattle has been known to stockmen and dairymen the world over for the past century or more. There is probably no disease or combination of diseases which distresses the dairyman more or causes greater economic loss to him than this particular infection.Up to the year 1896 the etiology of this disease remained obscure. In that year Dr. Bang2 of Copenhagen isolated the organism which is now recognized as the specific etiologic agent in this disease. It is a short gram-negative, nonmotile bacillus which is somewhat difficult to isolate, but when once it has been grown successfully on artificial mediums its further cultivation presents few difficulties. The work of Bang shows that this bacillus is

The passage of substances through the intestinal wall, and the effect of the ingestion of biologically active bodies on the reactions in the blood and other tissues has been a subject of much interest to many, and especially so to pediatrists. We hope to throw some light on this problem by the demonstration of the fact that a specific reaction can be obtained in the blood of a considerable number of children.The specific reaction in question is that of the complement fixation test, using the bacillus of infectious abortion of cattle as an antigen. The significance of this particular reaction becomes apparent when we consider that epidemic abortion is common among cattle; that the presence of the Bacillus abortus can be demonstrated in cow's milk, and that the reaction is seemingly specific.The discussion concerning the enteral absorption of homologous or heterologous proteins has been, and still is, of

Experiments were conducted to determine the effect of soil moisture level on yield, consumptive use of water and root development by sugar beets. The studies were made on areas with two water table depths to determine generally the extent to which sugar beets can use moisture in the moist zone immediately above a water table. When sugar beets were allowed to remove 43, 75 and 95% of the available moisture in the root zone prior to irrigation, yields were 23.4, 22.0, and 16.9 tons per acre, respectively, on an experiment where plants could not obtain ground water. In a second experiment on an area with a water table at 4 to 4.5 feet below the soil surface, yields were 22.9 and 23.5 tons per acre when plants were allowed to extract 54 and 66%, respectively, of the available moisture prior to an irrigation. A third treatment not receiving irrigation, but drawing heavily on ground water, yielded 20.1 tons per acre. Consumptive use of water for the growing season by sugar beets was 23.4, 22.5 and 19.0 inches, depending on whether 43, 75 or 95% of the available moisture was removed prior to an irrigation. The largest amount of water was lost from the surface foot of soil in all periods of measurement with progressively smaller amounts from deeper depths on the two wetter treatments. Moisture use was related to the depths containing available moisture in the dry treatment. Moisture level had no effect on the rate of root extension or the shape of the commercial root.

The relationship existing between the effects of potash fertilizers, physical and chemical properties of the soils and moisture tension treatments on the yield and potassium and sodium uptake by sugar beets in south central Montana have been studied. Small sugar beet yield increases due to potash fertilizer were obtained on calcareous soils containing quantities of exchangeable potassium much in excess of what is usually thought to be adequate for maximum growth (i.e., from 0.82 to 1.79 m.e. per 100 grams soil). Another experiment having moisture tension variables was conducted on a soil with relatively few large pores particularly at the 6 inch depth. Late in the season, sugar beets growing on low tension treatments showed evidence of potassium deficiency and petioles contained 31% less potassium than petioles from high tension treatments. Since yield increases due to potash were obtained on soils with a very few large pores and maintained at low moisture tensions, it is suggested that poor soil aeration was a major factor contributing to the low potash availability. The lack of any relation between potassium uptake and the amounts exchangeable also may suggest that potassium absorption was dependent on soil aeration.

THE CEREBRAL complications associated with pneumonia have received but scant attention in American literature, although numerous reports are available in many of the foreign journals (Bonaba, Marcos and de Agorio1; Comby2; Bonaba, Boni and Barberouse3; de Filippi and Fernández4; Nové-Josserand and associates5; Gareiso and Sagreras6; Mollard and Dufourt7; Eschbach8; Stephan9; Comby10). Actually, such complications are not infrequent and may appear at the onset or at the height of the pneumonia or during convalescence, after the patient has become afebrile and appears well along the road to recovery. Cases often reveal a wide variability of symptoms, ranging from such generalized complaints as headache, vomiting, vertigo and lethargy to the more dramatic complications of coma, convulsions, delirium, monoplegia, hemiplegia, athetoses and psychic disturbances (Baker and Noran11). The most common picture seen is that of acute meningoencephalitis. In many instances, after a

Alfalfa produced nearly as much forage under arid conditions without irrigation as with 6 irrigations per year when the water table was 5 to 9 feet below the soil surface. However, appreciable salt accumulation occurred in the 3‐ to 7‐foot soil depth.

Subsoiling to 16 and 24 inches depth did not increase corn yields in Iowa during 1955, 1956, and 1957. In Illinois, Subsoiling to 12 and 18 inches depth produced a significant corn yield response at the lower depth in only 2 out of 14 experiments in 1955 and 1956. Fertilizer placed deep in the subsoiled channel was not as effective as fertilizer plowed under in the Iowa experiments.

A sampling procedure was developed to measure the distribution of soil aggregate diameters in the row zone of row‐cropped corn. At each of 31 locations, 4 preplant tillage treatments were used to obtain different soil conditions in the row zone. Undisturbed soil cores were taken from the 0‐ to 3‐ and 3‐ to 6‐inch layer. Dry aggregate‐diameter distribution and dry bulk density (DB) were measured for the 0‐ to 3‐inch layer (DBonly in the 3‐ to 6‐inch layer). Within 6 weeks after planting DBincreased, but the logarithm of geometric mean diameter (log GMD) and the dispersion of aggregate diameters (σlog d) changed differently depending on tillage treatment and year of study. DBin the 3‐ to 6‐inch layer did not change. Large differences in these measurements were observed among tillage treatments, but within a year of field trials no treatment × location interaction occurred. Some comparisons of measurements were consistent between years and others were not. DBof the 0‐ to 3‐inch layer increased among tillage treatments as σlog dincreased, but decreased less as the log GMD increased. A similar relation was shown in the laboratory using mixtures of aggregate‐diameter separates. These changes in DBwere mainly due to modification of the interaggregate void space. In the laboratory an increase in weight fraction of water was observed from increasing σlog d. Hence, both log GMD and σlog dare measurable parameters of soil conditions in beds of aggregates, and may help to explain soil water retention and movement, evaporation losses, seed‐soil contact, and root‐soil contact.

Corn growth was measured in 23 location‐years in the eastern United States, where an average soil temperature reduction of 2.2°F. at the 4‐inch depth was obtained by a straw‐mulch treatment as compared to unmulched treatments during the first 6 weeks following planting. For soil temperatures ranging from 60° to 83°F., the ratio of the dry matter produced on the mulched treatment to that produced on the unmulched treatment was linearly related to the 4‐inch soil temperature. The validity of this linear relation was supported by data from experiments in the greenhouse and laboratory where growth of corn was observed under carefully controlled temperatures. For field conditions, a corn growth vs. soil temperature relation was constructed from the above linear relation, and the estimated optimum soil temperature for corn growth (dry matter production) was 81.3°F. The effect of soil temperature on four different growth measurements (height, dry matter production, yield of N, and yield of K) of corn was different for each growth measurement in both the field and the greenhouse.

Estimated critical limits of selected soil parameters for evaluating tillage requirements for corn in the water management (interrow) zone and seedling environment (row) zone are presented. Suggested parameters for corn in the western Cornbelt for the row zone include soil temperature, secondary aggregate size, bulk density and volume of the zone. For the interrow zone, the parameters include depression storage, plow layer storage, and/or surface mulch or surface microrelief. The research basis for the selection of the critical limits and soil parameters is discussed. This approach can be used to evaluate tillage needs for other crops.

The numerical procedure of Hanks and Bowers was used to solve the moisture flow equation for boundary conditions corresponding approximately to those existing for infiltration into a field soil. Water diffusivity and retention data, necessary for theory calculations of infiltration, were measured on field cores by the outflow method. Infiltration estimates were obtained for a simulated two‐horizon soil with three nonuniform antecedent moisture profiles. Calculated infiltration rates were in good agreement with field rates measured with a sprinkling infiltrometer. Although not considered a substitute for field measurement, the numerical procedure appears to be a useful means of supplementing field measurement data by providing estimates of infiltration for simulated conditions of practical interest which are difficult to evaluate in the field.

On corn plots in Iowa, South Carolina, Ohio and Minnesota which were treated with oat straw either plowed under or on the surface and with two levels of N, measurements were made of soil temperature at the 4‐inch depth, and these measurements were correlated with dry matter yields of corn early in the season. The data from Iowa, Minnesota and Ohio support a theory that early season corn growth is decreased by low temperatures caused by a mulch of crop residues. The data from South Carolina, where soil temperatures were considerably higher than in the three other states, showed that the mulch did not appreciably influence the growth rates. The data from all four of the states agreed in a general way with data of Lehenbauer who found that for a range of temperatures from about 50° to 86° F. there is an increase with temperature of seedling growth rate; whereas around 86° to 90° F. there is little influence; and from about 90° to 111° F. there is a decrease. From the soil temperature measurements taken at a 4‐inch depth it was shown how temperatures for other depths could be deduced from a theoretical expression based on heat flow theory. A detailed example of the use of the heat flow theory in studying the mulch problem in practical experimentation is presented.

Using rainfall intensity and runoff rate measurements for plots with slope lengths of 36.3, 72.6 and 145.2 feet, infiltration rates were determined by the graphical method of Sharp and Holtan for 10 storms occurring during the years 1938 to 1942, inclusive. The plots on Marshall silt loam had been cropped to continuous corn since 1932. The average initial infiltration rate for all storms and all slope lengths was 0.79 inch per hour and the final infiltration rate was 0.21 inch per hour. The final infiltration rate varied with storms and slope lengths from 0.60 to 0.10 inch per hour. The average infiltration rate curve calculated from the mean of all curves for all storms and all slope lengths was expressed by the equation f = 0.211 + 1.019 e‐0.056t. Final infiltration rate appears to increase up to June and July and then decrease rather sharply during August and September.

Improved methods of information retrieval and handling are urgently needed, especially by researchers and others who use published literature. Computerized information systems offer scientists great help in maintaining personal reference files. A number of computerized retrieval systems are available. However, this report is limited to experiences with one system, which has been successfully employed to: (1)create, maintain and use a bibliographic file for soil scientists; (2)prepare an author‐keyword index of about 600 soil and water references prepared by ARS staff; (3)answer general requests for information by writing search questions; and (4)list manuscripts by scientists, locations and journals. Computerized information retrieval systems are not difficult to establish or use; obtaining a data base is the most costly phase of the system. Any information retrieval system should be viewed as an adjunct to scientific literature study, not as the sole source of information.

Some strains of Bacillus proteus obtained from human lesions are pathogenic for rabbits, rats, and guinea pigs. There is good evidence that these strains are also pathogenic for man. All cultures obtained from sources other than human infections were non-pathogenic for the laboratory animals. A non-pathogenic culture may be made pathogenic by the use of aggressins or by inoculation into the anterior chamber of the eye. Proteus cultures lose their virulence rapidly when grown on artificial media. The lesions produced in animals are either simple abscesses, proliferative lesions, or a mixed exudative and proliferative lesion. The proliferative lesions consist mainly of epithelioid cells apparently of connective tissue origin. No giant-cells of the Langhans type are present. The histological type of the lesion does not depend upon the strain employed. Neither does it bear any relation to the clinical severity of the case. The ability to produce the characteristic lesions has no necessary connection with the toxicity of the bacteria. The proteus bacteria probably play a more important part in human pathology than is generally believed.

Alfalfa‐red clover stands and growth frequently were poorer in a band at the south side of 80‐inch spaced east‐west planted corn rows than in the remainder of the interspace between the rows. Stands between north‐south corn rows were usually more uniform. The band of poor stand on the south side of east‐west rows coincided with a band of soil receiving near full sunlight throughout the day. This resulted in higher soil temperature and frequently lower soil moisture.

Because large amounts of sediment come from gully banks in the coarse loess soils of the Lower Missouri River Basin, a study was made of the factors influencing the stability of gully banks. The approach was to consider the action of forces within the soil mass forming the wall of the gully. A two‐dimensional stability analysis was made using the Simplified Bishop Method of Slices. If the angle of internal friction is ≤ 35°, calculated factors of safety indicate that vertical, saturated, or near‐saturated gully walls in loessial soils will fail if a ground water table exists at the base of the wall and if the cohesion for the saturated soil system is zero at a hydrostatic pressure of zero. Although gully bank stability is sensitive to the angle of internal friction, the calculated stability is relatively insensitive to slope height and soil bulk density. Tension cracks that frequently open at some distance back from the gully face do not materially influence stability. The effect of infiltration rate into the soil on the stability of the gully wall depends upon the rate of water conductivity through the soil and upon the cohesion of the soil or the level of the ground water table. Increasing the infiltration rate decreases the stability.

During simulated rainfall, increases in tillage‐induced random roughness and pore space increased water infiltration before runoff started but did not significantly influence infiltration throughout a 5‐cm runoff period. Random roughness provided a greater accounting of infiltration variation among tillage treatments to initial runoff than did total pore volume of the tilled layer. Freshly turnplowed alfalfa‐bromegrass sod on Barnes loam and Nicollet sandy clay loam soil provided random roughness and pore space conditions that could accommodate without “failure” the major portion of rainfall energy (as evidenced by EI) expected in west central and southwestern Minnesota during the first 2 months following row crop planting. This is the critical runoff‐erosion period in the Corn Belt.

Porosity of individual surface soil aggregates at moisture contents ranging from saturation to air‐dry was determined by glass bead displacement. Measurements were made on aggregates having a diameter range from 0.5 to 10 mm at air‐dry moisture content and 2.0 to 10 mm at suctions ≤ 15 bars. The coefficient of variation for a determination of aggregate density (g cm‐3) ranged from 1 to 11% depending on diameter and moisture content. The major contributor to precision loss was heterogeneity of soil aggregates and not precision errors of the method. More than a 50% decrease in specific total pore volume (cm3g‐1of oven‐dry aggregate) upon desorption from saturation to air‐dry was found for three aggregate sizes each from a Chernozem and a Chestnut soil. In both soils, the percentage of pores having diameters > 29 µ increased as aggregate diameter increased. The volume fraction of air at a given moisture content increased as the diameter of aggregate increased. For all aggregate sizes, the volume fraction of air was ≥ 0.10 at 0.33 bar suction. The two soils exhibited different types of shrinkage curves.

In the temperature range of 16° to 20°C., a 2°C. differential in soil temperature had a measurable effect on the rate of conversion of NH4‐N to NO3‐N. However, as soil temperature increased to the range of 25° to 30°C. or as the supply of NH4‐N became limiting, differences in NO3‐N production resulting from small differences in soil temperature were not observed. In field soil, very early in the season when soil temperature was in the range of 16° to 20°C., mulched soil was 1° to 2°C. cooler than bare soil. During this period greater accumulation of NO3‐N could occur in bare than in mulched soil as a result of the temperature difference. As measured in the laboratory, NO3‐N production was retarded at soil moisture tensions below 50 cm. of water. At still higher moisture levels, considerable mineral N was lost from the soil. Measurements in the field showed that the soil moisture content of mulched soil exceeded that of bare soil. For short periods of time the moisture level of mulched soil was high enough to cause retarded nitrification and loss of N.

In field experiments it has been observed that nitrogen availability to corn is frequently depressed where crop residues low in nitrogen remain on the soil surface as compared to where the residues are incorporated in the soil. The purpose of this investigation was to evaluate the immobilization of soil nitrogen as influenced by position of crop residue with reference to the soil. In greenhouse experiments nitrogen uptake by Sudangrass was significantly greater when cornstalk residue was applied to the soil surface than when it was incorporated in the soil. By comparison with a treatment receiving no residue it was concluded that considerable nitrogen was immobilized by cornstalk residue incorporated in the soil, whereas no immobilization occurred with cornstalk residue on the soil surface. On the other hand, in laboratory experiments it was demonstrated that soil nitrogen could be moved to and immobilized in low‐nitrogen residue on the soil surface and that the movement of nitrogen into surface residue was enhanced in treatments which were subsurface irrigated and in treatments held at a low‐air humidity. Also it was found in laboratory experiments that subsurface residue decomposed more rapidly than did surface residue and that this more rapid decomposition resulted in an increase in percent nitrogen but in a decrease in total nitrogen of the residue. Likewise, percent nitrogen of surface residue increased, but total nitrogen increased or decreased, depending upon the conditions of the experiment. The results of a field experiment demonstrated that surface applications of low‐nitrogen residue without added nitrogen fertilizer resulted in decreased nitrogen uptake by corn and yield of corn. However, when nitrogen fertilizer was added along with the residue, yields were increased above the unmulched check.

With subcutaneous inoculations of 4000 to 8000 average lethal doses of a Type II pneumococcus in mice, the survival rates at both 30 and 60 days were (1) with 0.5% sulfapyridine in the food, 44%, and (2) with 1.0% sulfapyridine in the food, 63.4%. It is believed that the slight variations in drug-intake from day to day are more than counterbalanced by a more or less continuous drug-absorption from ingested food plus drug.

The experiences of one of us (Larson1) with the detoxifying action of sodium ricinoleate in the case of several bacteria and several bacterial toxins, suggested the possibility of actively immunizing monkeys against experimental poliomyelitis through the medium of this soap. Consequently we obtained a sample of the “M. A. strain” of poliomyelitis virus from the Rockefeller Institute of New York, through the courtesy of Dr. Simon Flexner, and established the disease in our own animals.In general, we are proceeding according to the following plan. A virulent sample of poliomyelitis is obtained by producing the disease in an animal by the intracerebral injection of stored glycerinated virus. The animal is then killed by chloroform during the height of the disease, and immediately about a gram of the brain is removed sterilly and ground up in 5 to 10 cc. of physiologic saline solution. This emulsion is used to continue the disease in another animal and to prove the potency of the soap-virus emulsion injected into the animals being immunized. At the same time another gram of the brain is ground up and emulsified with 5 to 10 cc. of 1 per cent aqueous sodium ricinoleate. This soap-virus emulsion is injected by different routes in normal animals to establish the assumed immunity. Some time later these animals are injected intracerebrally with a virulent saline emulsion of poliomyelitis brain to test their resistance.Approximately 60 injections of the soap-virus emulsion have been administered in the animals by the cerebral, subcutaneous or intraperitoneal route. None of these animals have developed poliomyelitis within the incubation period of the disease following such an injection, though 2 of them showed complete hemiplegia immdiately after frontoparietal cerebral injection, and died within 2 or 3 days.

In papers published from this laboratory during the past three years attention has been directed to changes produced in cultures of pellicle forming bacteria by adding surface tension depressants to the media. The changed form of growth from pellicle to diffuse growth thus induced has been attributed1to differences in degree of wetting of the bacteria.We have found that the tubercle bacillus can be made to grow beneath the surface of glycerine broth by appropriately depressing the surface tension of the medium. The tubercle bacillus, like other pellicle forming organisms, we believe, grows on the surface because of its high fat content which tends to resist wetting. In a recent paper Larson and Larson2have shown that practically all aerobic bacteria may be grown on the surface of broth by growing them on media from which they may store up fat in increased amounts.The present study concerns the effect of wetting on the viability and pathogenicity of the tubercle bacillus. A virulent culture of this organism was grown in glycerine broth to which had been added sufficient soap to depress the surface tension to 44 dynes.Growth under these conditions is under the surface of the medium and is slower than when grown under the usual conditions. Inoculation of such cultures subcutaneously into the flank of guinea pigs was followed by a slight enlargement of the inguinal glands of the side inoculated. Within the following ten days this glandular enlargement had receded, after which the animals showed no signs of tubercular infection.The mechanism of this rapid loss of pathogenicity is difficult of analysis at the present time. However, if the hypothesis is accepted that pellicle formation of the tubercle bacillus is an indication of minimum wetting, the same arguments may be used to explain altered pathogenicity.

The results of experiments on the protection of rabbits, infected with pneumococci, by oral administration of sulfapyridine have been reported previously.1The purpose of this communication is to present data obtained in the study of the immunity in animals that had recovered from the infection produced under such circumstances.Rabbits weighing approximately 2 kilos were inoculated intracutaneously with 0.3 cc of a 1/100 dilution of an 8-hour culture of a pneumococcus type II. The inoculum contained an average of 300,000 organisms as determined by plate-count. The virulence of the organism is such that an average of 1.5 organisms are necessary to cause an infection in 66% of a statistically sized group of mice weighing 20 g. This we have taken to be our minimal lethal dose. Its virulence for rabbits is such that 0.3 cc of a 1/1000 dilution of the original culture, containing 30,000 organisms, will kill all of the rabbits inoculated.The drug-treated animals were given sulfapyridine orally in a 10% acacia suspension. Each animal received a total of 5 g of the drug, 0.5 g 1 hour before infection, 0.5 g 3 hours after the initial dose, and 0.5 g every 12 hours thereafter until the full dosage was administered.Daily record was made of the temperature, and the size and nature of the skin-lesion. Rabbits recovering from the primary infection were reinoculated intracutaneously in the same general areas as previously, but not at the site of the original lesion if a scar had persisted. Only normal areas of the skin were used for reinoculation.Type-specific Immunity. Twelve rabbits reinoculated intracutaneously with 0.3 cc of the whole 8-hour culture of the homologous type II pneumococcus 30 days after the original infection, showed no rise in temperature, and no local reaction around the point of inoculation.

Increases in soil temperature accelerated rate of emergence, rate of growth, and promoted earliness in corn. Corn growth rates approximately followed the Van't Hoff law, the Q10° c. of that law being from 2.0 to 2.8 for the average temperature range tested, 60° to 80° F. Corn yields appeared to increase with increases in soil temperature up to a point and then decreased with further increases in soil temperature. The most favorable soil temperature at the 4‐inch depth for corn growth in central Iowa appears to be about 75° F.

The tensile strength, tensile axial strain, and tensile strain energy were determined for Na‐, K‐, Ca‐, Al‐, and Fe‐saturated montmorillonite over the water vapor pressure range (P/Po) from 0.02 to 0.92. The procedure used was direct tensile stressing of oriented clay films. Measured tensile strengths ranged from 366 kg cm‐2for Fe montmorillonite at 0.02 P/Poto 19 kg cm‐2for Ca montmorillonite at 0.92 P/Po. Strength decreased rapidly with added increments of water during initial interlamellar expansion and continued to decrease at a slower rate with further additions of water. In general, strength decreased in the following order: Fe > K ≥ Na > Al > Ca. The tensile strength of Na montmorillonite was of the same order of magnitude as the force required to separate two Na clay platelets as determined from adsorption/desorption water isotherms. Axial strain was independent of P/Poabove 0.4 for all systems except the Na‐saturated clay. For Fe montmorillonite, strain was insensitive to water content above 0.15 P/Po. Monovalent clay specimens required the most energy to rupture and divalent samples required the least energy. Aluminum and Fe clays required an intermediate rupture energy. The greater tensile strength and low axial strain of the Fe montmorillonite suggested that a different mechanism controlled the failure characteristics of this clay. Hydroxy iron material may be the major cementing agent in the Fe system. The data show that saturating cation played a dominant role in the strength‐energy properties of the other homoionic clays.

Presents letters to the editor published in this issue of the periodical. Reference to the article "Hooperism Clears the Air,'" by Thomas Whiteside, published in the May 5, 1947 issue of the periodical; Information on U.S. President Harry S. Truman's proposed aid to Greece and Turkey; Political turmoil caused by bandits in Mexico.