Grams Of Water Research Articles

Natural Mulches or "Litter" of Grasslands: With Kinds and Amounts on a Southern Prairie

terms and crop residue are commonly used by agronomists to indicate *dead material on the surface (Hughes and Henson, '30). Soil conservationists have used these terms in cropland description, and in forest descripton (Bennett, '39). Horticulturists also use the term (Bailey, '33). Foresters have classified characteristic layers of dead materials that occur on forest floors including and unincorporated humus (Hawley and Committee, '44). Soil scientists commonly employ the term AOO horizon to designate an upper layer of loose leaves and debris, largely undecomposed, and the term AO horizon to designate lower layer of debris partially decomposed or matted. Both rest upon the Al horizon where amorphous remnants are found mixed with mineral particles and constitute the upper layer of the true (U. S. Dept. Agric., '38). Range conservationists and grassland ecologists have long been aware of the importance of natural mulches on grasslands though there is no standard terminology and usually no definitiveness as to the portion of total surficial matter so considered. As early as 1913 Barnes ('13) in describing the virgin range stated, The spring snows lay long under the folds of the grass, weeds or brush that covered the ground. Let the wind blow as it pleased, it could not blow the snow entirely off the ground. A certain amount of it was allowed to remain to melt and soak into the ground, thus bringing the green sprouts out early in the spring, and it took a long dry spell to make any great impression on the Sampson ('23) referred to the importance of old growth and unused vegetation. Talbot ('37) stressed the need of leaving some unused forage for soil protection. Weaver and Flory ('34) in referring to mowed climax prairie near Lincoln, Nebraska stated that mulch of fallen leaves, fragments of stems, flowers and fruits, etc., forms a more or less continuous of varying thickness. This may have a dry weight of 50 to 225 grams per square meter on uplands and over 1,000 grams on lowlands. Flory ('36) stated that the amount of on a square meter of grassland was often 225 grams and that it could absorb 650 grams of water. Stoddart and Smith ('43) in their well-documented textbook on range management found it necessary to use not fewer than four terms in referring to surficial residuum on range land, including vegetational debris, protection cover, duff, and litter. U. S. Forest Service ('36) in the comprehensive report entitled, The Western Range, refers to plant cover and organic mulch. It is also stated that On the virgin range dead plants and herbage formed a ground and eventually mixed year after year with the mineral soil. . Allred ('40) mentioned the large quantity of new and semidecomposed litter on a properly managed range. Weaver and Clements ('38) in defining refer only to the forest floor. Carpenter ('38) in his ecological glossary limits use of the term to forest floor description. need for a more specific terminology applicable to grasslands is apparent.

Letter to Editors

MAY I hope that the “jool” pronunciation of Joule's name will be adopted, if only in order to preserve the mnemonic: “Old Dr. Joule he made this rule: The self-same energee Which lifts a gram of matter to 4 2 6 4 0 c. [centimetres] Will heat a gram of water through One centigrade degree.”

Gastric Mucosal Relief

RECENTLY, in this country, there has been a revival of interest in the demonstration of mucosal patterns in the stomach and duodenum, as an aid in establishing the normal and abnormal in gastric and duodenal diagnosis. This paper will attempt to demonstrate the possibility of a modification of the sedimentation method, by no means a new idea, but one which represents a slight departure from those used in the past. Historical Note As early as 1897, Raux and Balthgard, apparently independently and contemporaneously with Walter Cannon in this country, first used a bismuth opaque meal in demonstrating the motor phenomena of the stomach. Holzknecht and his group, in 1898, probably saw fluoroscopically the flow of bismuth opaque meals over the gastric rugæ. In 1906, they used a watery suspension of bismuth subnitrate in the preliminary part of the fluoroscopic study of the stomach (10 grams bismuth subnitrate in 50 grams of water, to which was added a tablespoonful of milk sugar). Palpation of the stomach in the erect posture made possible the visualization of the mucosal folds. After this procedure and while the stomach still contained the bismuth suspension, they distended the stomach by having the patient ingest an effervescent mixture of from four to five grams tartaric acid and from five to seven grams of sodium bicarbonate. This they followed by the usual opaque meal, four hundred grams of milk gruel with thirty-five grams of bismuth subnitrate. This examination is detailed because of its resemblance to our own procedure. With the advent of the Snook x-ray transformer, in 1907, and the distinct improvement in visualization due to “stopping” gastric peristalsis, further impetus was given to gastro-intestinal examinations by these methods. Cole, in 1909, demonstrated gastric rugæ by using the principle of sedimentation of bismuth subnitrate from a watery suspension as a special technic. His first films compare very favorably with the more modern methods of examination. Akerlund, in 1921, working with Forssell, whose classic monograph in 1913 laid the fundamentals of the anatomy and physiology of the stomach before the profession, applied the method of the “thin layer” to diagnosis of the duodenal bulb lesions by exerting external pressure to displace all but a thin layer of opaque medium from the bulb. Since then, innumerable observers have contributed both to the relief and thin layer methods, the majority, however, having tended to avoid the principle of sedimentation to demonstrate the rugal pattern. Pribram and Kleiber (1927), Hilpert (1928), and Vallebona (1926) revived the use of barium suspension and air distention. Small amounts of barium suspension were ingested and distributed by manual pressure, then the stomach was distended by air injected through a small tube (Pribram, Kleiber, and Hilpert), or by chemical means (Vallebona).

The Compressibility of Solutions of Three Amino Acids

The compressibility of aqueous solutions of glycine, α-amino butyric acid, and ε-amino caproic acid have been measured over the concentration range up to 2.5 N at 25° and 75°C and up to a maximum pressure of 8000 kg/cm2. The results are exhibited in tables giving the volume in cm3 as a function of pressure, temperature, and concentration of that amount of solution which contains one gram of water, and in figures showing the apparent molal volume at 25° as a function of pressure and concentration. The general character of the results is complicated; the most striking result is that at low pressures the apparent compressibility of the acid in solution is positive, which is opposite in sign from all other known solutes. A connection is probable with the high dielectric constant. Other qualitative aspects of the phenomena are discussed.

The osmotic passage of water and gases through the human skin

It has been known for long that part at least of the “insensible” passage of water which is constantly passing through the skin is not due to the activity of sweat-glands, since in the rare cases of congenital absence of sweat-glands some water is nevertheless given off through the skin. Two cases of this kind were investigated by Loewy and Wechselmann (1911), who inferred that at an ordinary air-temperature as much as 18 grams of water might pass through the skin in an hour. The cases were those of two brothers, whose father had apparently suffered from the same defect. A further, more complete, study of a similar case was recently made by Richardson (1926). In our previous paper (1929) we brought forward evidence to show that in ordinary insensible perspiration through the skin, salts do not penetrate the skin in anything like either the same concentration or the same composition as would be the case if they had been excreted in sweat, and several similar results were given by Moss (1927). Hence since sweat contains salt, and in fairly constant concentration, little or none of this insensible perspiration is due to sweating, and the passage of water is presumably due to an osmotic process. The present paper contains further evidence in this direction, together with data as to variations in the osmotic transference and their relation to regulation of body-temperature. Variations in the rate of transference of gases through the skin have also been studied. We may define osmosis as the passage, molecule by molecule, of a substance, such as water, through a membrane or surface which is permeable to it, though it may not be to another substance present in the same state on one side of the membrane or surface. The consequence of the presence of the other substance is that the substance which can pass through the membrane can do so against adverse pressure on the side on which the other substance is present; and the maximum amount of this pressure is known as the osmotic pressure. As was pointed out recently by one of us (Haldane, 1928), this passage is due simply to diffusion, the diffusion-pressure of the substance which passes through being necessarily greater on the side from which it passes, so that for this reason the substance can pass through against mechanical pressure. It is thus simply with a diffusion process that we are dealing in the case of osmotic transfer of water through the skin, and what is usually called the osmotic “pressure” existing in a solution is more correctly called osmotic depression. It is with this depression that depression of the vapour-pressure of the solution runs parallel.

The determination of water in glycerols

Water in concentrated glycerols may be satisfactorily determined directly by the Bidwell-Sterling distillation method, using toluol as the boiling liquid. A variable but very small amount of glycerol is carried over with the water. In no case in our analyses did this glycerol carried over amount to as much as 0.10 gram, and the correction to the apparent per cent of water in the sample did not exceed 0.15% in any of the glycerols containing up to 10% of water. The use of a solvent like xylol boiling appreciably above 100°C is not advisable since it causes considerably more glycerol to be carried over and does not markedly shorten the time of distillation. An analysis made by this method on a 25.00 gram sample of dynamite glycerol to which 2.80 grams of water was added, producing a sample containing 10.37% water, gave a recovery, corrected for 036 grams of glycerol carried over, of 10.39% water. On the A. O. C. S. Standard Crude Glycerine sample, Mr. Church reports that four laboratories found an average of 4.90% moisture by the P2O5-vacuum method. We found 4.99% moisture by direct distillation in this same sample.

The Two Calories

MUCH confusion is caused by the use of the word calorie in two different senses—one to signify the amount of heat required to raise the temperature of one gram of water 1°C., and the other to represent what is really a kilocalorie, or the amount of heat required to raise 1000 grams of water 1°C. The only difference between the means of distinguishing the two units is that the large Calorie is spelt with a capital initial letter, and unless great care is taken this may be set up as a ‘lower case’ letter by the compositor. May I suggest that the confusion could be avoided—at least so far as the printed word is concerned—by spelling the large unit with a capital letter K, thus, ‘Kalorie.’ The use of the letter ‘k’ in this way is in conformity with the principle adopted in the designation of metric units generally.

A Useful Electric Cell

TAKE a glass vessel, a porous cell, a zinc rod and a carbon plate, such as are used in the ordinary Leclanche cell (a circular glass vessel of the same capacity is better). Prepare a solution of 20.4 grams of potassium dichromate and 87.4 grams of sulphuric acid (sp. gr. 1.75) in 350 grams of water and pour it into the glass vessel. Place the carbon plate in this solution. Fill the porous cell with a solution of 14.5 gm. of ammonium chloride in 200 gm. of water and place it in the glass vessel containing the dichromate solution. The amalgamated zinc rod is placed in the porous cell. The E.M.F. of this cell is 2 volts. The internal resistance is about 0.6 to 0.8 ohm. When continuqusly used, it gives a constant current for more than 12 hours, and the E.M.F. remains unchanged. The rate of dissolution of zinc (when a rod of zinc is used) is only 2.5 gm. in 12 hours, while in the bichromate cell the rate is 12 gm. When used intermittently, the cell remains efficient for more than three weeks.

Evidence of a structure in gelatin gels.

Bancroft1 recently reported some conclusions drawn from unpublished data of a Mr. Cartledge who dried gelatin gels of different concentrations down to a 96 per cent. gelatin content and then allowed these dried sheets to again imbibe water. It was found that “each swelled rapidly to the original concentration and then took up water slowly.”We have conducted experiments similar to those of Cartledge and have secured comparable results. Thus a 10 per cent. gelatin gel dried down to less than 3 per cent. moisture content had imbibed at the end of 72 hours 6.45 grams of water per gram dry gelatin as contrasted with 4.30 grams water for a 40 per cent. gel similarly treated. Comparable differences were observed when the dried sheets were ground and uniform sized particles sieved out and tested for hydration rate and maximum hydration capacity.Our experiments indicate that gelatin gels have a structure and that this structure is fixed at the time of gelation and is not appreciably altered by drying the gel at ro...

Solar constant of radiation : C. G. Abbott. ( Proc. National Academy of Sciences, September, 1919.)

If we had no eyes we should still know of the sun by the feeling of warmth. The intensity of solar rays in any part of the spectrum can be measured by delicate thermometry. Vision and photography are both restricted within comparatively narrow limits of wavelength, and each differs in its sensitiveness from wave-length to wave-length. Ultra-violet, visible and invisible red rays, however, all produce their just and proportional influences on the bolometer, or thermopile. This is not universally known, and there are still many who suppose we should distinguish between so-called actinic, visible and heat rays. Doubt has been expressed, for instance, whether bolometric measurements give true indications of the intensity of those rays which promote plant growth. Such doubts are not justified, and we may expect very valuable results in the future from the application of the spectro-bolometer to the interesting questions of radiation and plant physiology. We use heat units to express the intensity of solar radiation. The solar constant of radiation may be defined closely enough as the number of degrees by which one gram of water at 150 centigrade would be raised, if there should be used to heat it all the solar radiation which would pass at right angles in one minute through an opening one centimeter square, located in free space, at the earth's mean solar distance. Experiments were begun about T835 by Pouillet and by Sir John Herschel for the measurement of this great constant of nature. The investigation has been continued by Forbes, Crova, Violle, Radau, Langley, K. Angstrom, Chwolson, W. A. Michelson, Rizzo, Hansky, Scheiner and others. It is an indication of the great difficulty of the research that entire uncer-

The Solar Constant of Radiation

If we had no eyes we should still know of the sun by the feeling of warmth. The intensity of solar rays in any part of the spectrum can be measured by delicate thermometry. Vision and photography are both restricted within comparatively narrow limits of wavelength, and each differs in its sensitiveness from wave-length to wave-length. Ultra-violet, visible and invisible red rays, however, all produce their just and proportional influences on the bolometer, or thermopile. This is not universally known, and there are still many who suppose we should distinguish between so-called actinic, visible and heat rays. Doubt has been expressed, for instance, whether bolometric measurements give true indications of the intensity of those rays which promote plant growth. Such doubts are not justified, and we may expect very valuable results in the future from the application of the spectro-bolometer to the interesting questions of radiation and plant physiology. We use heat units to express the intensity of solar radiation. The solar constant of radiation may be defined closely enough as the number of degrees by which one gram of water at 150 centigrade would be raised, if there should be used to heat it all the solar radiation which would pass at right angles in one minute through an opening one centimeter square, located in free space, at the earth's mean solar distance. Experiments were begun about T835 by Pouillet and by Sir John Herschel for the measurement of this great constant of nature. The investigation has been continued by Forbes, Crova, Violle, Radau, Langley, K. Angstrom, Chwolson, W. A. Michelson, Rizzo, Hansky, Scheiner and others. It is an indication of the great difficulty of the research that entire uncer-

Section V.—Tables

General Tables, giving the Facts of Observation ; namely, W, the weight, in grams, of the solution which contains m gram-molecules of the salt dissolved in 1000 grams of water; S, the specific gravity of this solution at the temperature, T, referred to that of distilled water at the same temperature as unity. From these data, Δ, the displacement of the solution, is obtained by the equation Δ = W/S, and it is expressed in grams of water having the temperature T. The symbol adopted for this unit is GT. The numbers printed in italics refer to specific gravities observed at the temperature printed in italics.

Section XIV.—The Specific Gravity and the Displacement of Solutions of the Chlorides of Beryllium, Magnesium, and Calcium.

For the purpose of determining these constants, hydrometric observations were made on solutions of the three salts the concentrations of which ranged from 1/2 to 1/1024 gram-molecule per thousand grams of water, the experiments being made with the closed hydrometers Nos. 3 and 17. Experiments were also made on strong solutions of calcium chloride and magnesium chloride, using the open hydrometers A and B ; the concentrations of these solutions varied from 1 gram-molecule per thousand grams of water to the highest attainable degree of supersaturation. It was when the experiments on a supersaturated solution of calcium chloride were in progress that the observations were made which revealed the remarkable state of unrest in that solution which preceded its partition into crystals and mother-liquor with liberation of heat.

Section III.—Determination of the Specific Gravity of a Saline Solution

When determining the specific gravity of a saline solution by the hydrometric method, it is necessary first to find the weight which must be added to the hydrometer to immerse it to the 50-mm. mark when floating in the saline solution at the chosen standard temperature. This added weight is found by a series of observations in exactly the same manner as with the hydrometer in distilled water (see § 14 et seq.).The details of three series of observations with hydrometer No. 17 in a solution of ⅛ gram-molecule of cæsium chloride in 1000 grams of water at 19·50° are given as an example in Table C. This table is arranged in the same manner as Table A1.

Section IX.—Notes on the Values of v for the Enneads MR and MRO3

The increment of displacement produced in 1000 grams of water at 19·5° C, when 1/2 gram-molecule of potassium chloride is dissolved in it, is 14·001 GT; when a molecularly equivalent amount of potassium bromide is dissolved in the same quantity of water, the increase in the displacement is 17·547GT; when the salt in solution is potassium iodide, the number is 22·778 GT. Replacing, therefore, the chlorine by bromine increases the displacement by 3·546 GT; and if the bromine be now replaced by iodine, there is a further increase of 5·231 GT in the displacement; or, replacing the chlorine by iodine causes an increment of displacement of 8·777 GT.

Section XV.—On a Remarkable State of Unrest in a Supersaturated Solution of Calcium Chloride before Crystallising.

The primary purpose for which the open hydrometer was designed was to investigate the specific gravity and the displacement of solutions having concentrations in the neighbourhood of that of saturation. In § 90 we have seen the satisfactory result of experiments made for this purpose with solutions of chloride of calcium containing 6·3 grm.-mols. CaCl2 per 1000 grams of water. Experiments in the same direction were made with solutions of chloride of calcium of still higher concentration. A parent solution was made, which, on the basis of published data relative to the solubility of the salt, should be supersaturated at 19·5°C. With it, it was intended to produce the solution saturated at this temperature, and to study its specific gravity and that of solutions formed by diluting it with small quantities of water.

Section VIII.—Comments on the Changes in the Values of dΔ — v for Different Values of m in the Case of Solutions of Individual Salts of the Type MR And MRO3

The earlier introductory notes and discussion of the values of the specific gravity and displacement explain the precise meaning of these terms. A comparison of the values of the increment of displacement (v) caused by the dissolution of m grammolecules of a salt in 1000 grams of water with the difference (dΔ) of these consecutive increments of displacement possesses considerable interest.

The Unit of Heat

DR. JOLY'S strictures on the units of heat at present in use will meet with a ready endorsement from those who have worked on calorimetry. The large calorie is too large for convenience in most cases, and the small calorie is too small, while the confusion created by different writers using different units with the same name is scarcely reduced by their writing one with a capital and the other with a small c. A unit of convenient magnitude would be one equivalent to about 100 small calories, and 100 calories has, indeed, been adopted as a unit by more than one writer on thermochemistry. There is, however, what may be termed a natural quantity which is nearly equivalent to such a unit, namely, the heat of fusion on one gram of water at 0° C., which is nearly eighty calories. This appears to be just as suitable from other points of view as the heat of vaporisation of one gram of water at constant temperature and 760 m.m. pressure; and if this latter can be recommended on the ground that in defining it we replace the thermometer by the barometer, the former will possess the superior claim of (for all practical purposes) not depending even on the barometer.

THE ACTION OF ALKALIES ON HUMAN GASTRIC DIGESTION.

The frequency with which bicarbonate of soda is employed in gastric affections renders any contribution that enhances our knowledge of its action of interest to the profession. Dr. G.Linossierand Dr. G.Lemoinehave published in the June number of the<i>Archives Générales de Medicine</i>a valuable paper detailing the results of certain observations regarding the action of bicarbonate of soda and of carbonate of lime in a case of merycismus. Test meals consisting of 80 grams of bread, 80 grams of meat, and 250 grams of water were eaten by the patient, and every hour samples of chyme were obtained from the mouth into which it entered by the process of rumination. Under ordinary conditions in this patient the total acidity of the chyme was slightly pronounced, diminishing from the first to the third hour after a meal; the hydrochloric secretion was also sensibly inferior to normal, and