The

One fact is proved abundantly by a study of the flora of the serpentine barrens, and that is that the chemical character of the soil derived from a disintegration of the serpentine plays an unimportant part in the distribution of the plants mentioned. The distribution of such species is due rather to the physical conditions of the soil, especially with reference to water conductivity and water storage capacity (edaphic conditions). variation in the character of the plant associations described above is in the main due to the character of the soil. If the soil is present as a well-marked surface layer, then tree associations are found; if on the other hand the rock is exposed, herbaceous associations are the rule. The surface layers of serpentine rock are broken by weathering into angular fragments, which, lying loosely together, permit the percolation of the rain water down into the seams of the underlying rock. Such exposures, therefore, support plants that have adapted themselves to living in dry situations and have structural arrangements which prevent a rapid loss of water. JOHN W. HARSHBERGER.

UNIVERSITY OF PENNSYLVANIA.

THE AMOUNTS OF READILY WATER SOLUBLE SALTS FOUND IN SOILS UNDER FIELD CONDITIONS.

IN the investigations of the Division of Soil Management, in the Bureau of Soils, relating to the influence of soil moisture in crop production it has been found essential to take into consideration not only the varying amounts of available moisture in the soil but also the readily water soluble salts which this moisture carries in solution.

The sensitive and rapid methods which have been devised or adapted for this work enable us to determine the K, Ca, Mg, NO,, HPO,, SO,, Cl, HCO, and SiO, in the soil with an accuracy of duplication ranging usually from one to five parts per million of the dry weight of the soil examined and with rapidity such that eight men are able to complete the nine sets of determinations on twenty samples daily between 9 A.M. and 4 P.M.

As these methods are now used in our soil investigations, those for the K, Cl and HCO,

have been devised and adapted under the direction of Dr. F. K. Cameron; that for NO, by A. R. Whitson of Wisconsin and the writer; that for HPO, and SiO, by Dr. Oswald Schreiner; those for Ca and Mg by Dr. Schreiner and W. S. Ferris, and that for SO by J. O. Belz. The clear soil solutions for examination are obtained by using the effective filter devised by Dr. Lyman Briggs.

After extended observations it has been found that to recover the maximum amount of the readily water soluble salts which are present in the soil it is necessary to first render the sample water free by drying at a temperature of 110° to 120° C., as soils are dried for moisture determinations. Mr. J. O. Belz and the writer found, for example, that after ten times washing 50 grams of a coarse, clean sand containing 4.125 mg. of potassium nitrate, that the same sample oven dried after having been ten times washed in 100 c.c. of distilled water yielded when worked in the disulphonic acid a large additional amount of nitrates. Our actual figures are given below, where from 50 grams of sand we recovered:

As an average of the thirty-two determinations of NO,, SO,, HPO, and SiO, made by Mr. Belz, and of the C1 and HCO, made by Mr. A. T. Strahorn, it was found that from the oven dried samples we received 68.85 per cent. more NO,, 62.38 per cent. more HCO3, 62.42 per cent. more HPO,, 244.32 per cent. more SO, and 287.9 per cent. more SiO, than from the fresh field sample, but about the same amount of chlorine in each set of determinations.

This year, early in June, Dr. Schreiner and Mr. Ferris, of this Division, have shown by a less extended series of observations that the oven-dried samples yielded 54.15 per cent. more calcium and 109.03 per cent. more magnesia.

We were led to make these observations on account of the great difficulty in determining the true amount of nitrates in soil samples, on account of the rapid changes in nitrates which occur after a soil sample has been taken, the work being done to ascertain whether it would be admissible to render the samples water free to stop such action, and were surprised to find that we could recover from the ovendried samples more readily water soluble salts of nearly every sort determined than we could recover from the fresh sample. The reasons for this increased amount are discussed in a section of the report of our results for 1902 not yet published. In this discussion we assigned several causes, but regard the physical conditions produced by the drying as the chief one. It appears to be demonstrated that the strength of the soil solutions in the water films surrounding the soil grains increases as the surface of the soil grain is approached, in an undetermined ratio; and when a moist field sample is put into distilled water and shaken for three minutes the films of water which the soil grains and granules possess under the field conditions move about in the solution with the soil grains, and during the three minutes of agitation, which we have adopted as our practicable limit, only a portion. of the salts diffuse out into the surrounding water; but when the soil sample is rendered water free the readily water soluble salts are

deposited on the surface of the soil grains and the surface of the soil granules, so that when the distilled water is dashed upon them they go into solution; during the vigorous agitation, they are carried bodily away from the soil grains much more completely during the three minutes than is possible by the slower process of diffusion which must occur in the case of the moist sample, and on this account we recover a larger per cent. of the readily water-soluble salts which the soils

carry.

There is still another physical condition which makes it possible to recover a large amount of readily water soluble salts by washing the oven-dried sample. In the first place the soil granules are more completely broken down by the pestling to which the sampi: are subjected after being oven-dried, so that the deposited salts are more freely exposed to the water when it is put upon the samples, and are dissolved more quickly on this account. Further than this, while soil samples are drying in the oven the capillary action which is set up in the interior of the soil granules brings out upon their surface a considerable quantity of the salts, which in the moist condition are retained in the interior of the granules where the diffusion outward would be necessarily slower than if the granular condition did not exist and the salts were all in the water film surrounding the surface of the compound grain. This capillary action therefore which takes place during the time of drying, brings soluble salts where the water comes quickly in contact with them, even though the pestling does not completely break down the granular structure, which, as a matter of fact, it never does.

Large as are the amounts of readily watersoluble salts which we are recovering from our field samples, observations which we cite indicate that the amounts actually present are an undertermined amount greater than those we have found. As an example of the amounts of readily water-soluble salts which field soils carry, and as an illustration of the rapidity of securing results and the character of the results, the following table is given,

K.

Ca. Mg. No. HPO SO1. HCO3. CI. SiO2.
In parts per million of dry soil.
Surface Foot.

illustrating a single day's work on a set of samples taken from the surface four feet.

It is not, of course, affirmed that the amounts of the different ingredients found in the soils examined are actually in solution in the soil moisture as the sample comes from the field, although in my judgment the observations indicate that this is likely to be the case for most of the ingredients at least, but observations sufficiently demonstrative have not yet been made to warrant such a statement as fact. The five sets of determinations in each group are, in a way, made on duplicate field samples; that is, they are taken at the same time from the same field but from alternating plots, one of which, as the table indicates, has received no treatment, the others having received the amounts of stable manure indicated, or the amount of guano. These samples were taken early in the spring, only a few days after the application of the stable manure and fertilizers.

Observations similiar to these are being carried through the growing season on eight types of soil in four different states, the samples being taken simultaneously in the four

different localities. All of the different fields are under the same crop conditions, so that any differences in yield may be determined for comparison with the amounts of soil moisture and the amounts of readily water-soluble salts which the soils upon which the crops are growing are found to contain. F. H. KING.

BUREAU OF SOILS.

July 30, 1903.

CURRENT NOTES ON METEOROLOGY. PRELIMINARY METEOROLOGICAL OBSERVATIONS

FROM THE DISCOVERY' EXPEDITION. DR. H. R. MILL, in Symons's Meteorological Magazine for May, publishes some preliminary results of the meteorological observations taken on the British Antarctic Expedition near Mt. Erebus. The Discovery was in winter quarters in a sheltered position twenty-one miles from Mt. Erebus, in lat. 77° 49′ S., long. 166° E. Among the observations three facts are of special interest by reason of their bearing upon the theory of the general circulation of the atmosphere, which is just now much in debate. Lieut. Royds, in charge of the meteorological observations, reports that

'northerly winds seem most prevalent during the summer months, and I do not think they were ever recorded in winter.' Another point concerns the direction of the upper currents, which was determined by watching the drift of the smoke from Mt. Erebus. It appeared, from these observations, that the upper winds were usually southwesterly or westerly, i. e., they showed a marked tendency to blow out from the circumpolar region. A third characteristic phenomenon noted was the decided rise in temperature during southerly 'blizzards' in midwinter; a fall in temperature coming with a change in the wind direction to the eastward. As Dr. Mill points out, this rise in temperature should not be taken as an indication of higher temperatures farther south, but rather as a fahn effect, resulting from the mechanical warming of descending air currents.

pears that the curve of the isobars is an important determining factor in this problem. The investigation is an interesting one, and is likely to lead to similar detailed studies elsewhere.

THUNDERSTORMS OVER MOUNTAINS AND LOWLANDS.

IN the Meteorologische Zeitschrift for May, Hegyfoky points out that his observations of thunderstorms, carried on for a number of years in Hungary, show an earlier occurrence in mountainous districts than over lowlands. In mountains the maximum hours of occurrence were 11 A.M.-2 P.M., while, over the lowlands the period of maximum was 2-5 P.M. The studies of Héjas, on the thunderstorms of 1871-1895, in Hungary, brought out similar facts.

R. DEC. WARD.

SCINTILLATION OF STARS AND WEATHER

CONDITIONS.

SOME attention has of late years been paid to the scintillation of the stars, especially from the point of view of the bearing of this scintillation upon the upper air currents. A recent study of these scintillations by Rosenthal, of the Central Observatory of St. Nicholas at St. Petersburg (Meteorolog. Zeitsch., XX., 1893, 145-156), is directed towards the relation which these 'twinklings' have to weather conditions. As the basis for the investigation the writer takes the numbers (1 to 5) which indicate the quality of the seeing as noted in the observations of double stars through a refracting telescope at Domkino, 130 kilometers south of St. Petersburg, and at St. Petersburg. The observations were made on 142 evenings, from September, 1894, to November, 1900, and usually at about 9 o'clock. It appears that the least good seeing is noted on evenings with cyclonic conditions, while the best seeing is under neutral weather types. The relation of the seeing and the weather conditions has been so carefully determined by Rosenthal that he has been able to tabulate the probable seeing under a large number of different weather types at Domkino.

It ap

THE BRAIN OF PROFESSOR LABORDE.

PROFESSOR PAPILLAULT has published preliminary notes on the brain of the late Professor Laborde, the eminent French physiologist and anthropologist. The brain-weight was low, 1,234 gms., but whether this was due to atrophy from old age (seventy-three years) or disease is not stated. Dr. Laborde's notable powers of speech led Papillault to examine the subfrontal gyres of the two sides with especial care, and he found that the area in question was demonstrably larger and more differentiated on the left side (where the motor speech-centers lie in right-handed persons) than on the right. The same feature characterized the brain of Gambetta. Unfortunately, Papillault makes no mention of the degree of development of the left insula as compared with the right, for it is this region which is most concerned with the association of the receptive and emissary centers of the cortex and so constitutes the true psychic speech-center.

Papillault adds that, in general, the convolutions show an average degree of complexity.

E. A. SPITZKA. *Rev. de l'Ecole d'Anthropol., 1903, P. 142.

RADIUM.

THE London Times publishes a report of a paper which M. Curie has communicated to the French Physical Society. It appears that at the time of his lecture at the Royal Institution in June, the resources of that laboratory in producing and manipulating liquid gases were utilized in a new series of experiments. Professor Dewar had already in 1893 improved the calorimetric use of liquid gases by means of a combination of vacuum vessels so that heat-evolution at the temperature of boiling liquid air or hydrogen could be determined with accuracy. When a sample of radium bromide weighing 0.7 gramme was tested in this way it was found to be capable of volatilizing an amount of liquid oxygen and hydrogen equivalent respectively to 6 c.c. and 73 c.c. of the gases measured at the ordinary temperature. It seems that through a very wide range of temperature the thermal emission remains Whether at the temperature of unchanged. a summer day or at that of liquid air, the emission of heat goes on without perceptible variation.

When, however, we make a long downward stride from liquid air to liquid hydrogen, radium shows that it is not always unaffected by external temperature. Within a comparatively short distance of the absolute zero a change occurs in the rate of heat-emission, but not in the direction that might be anticipated in view of the effect of low temperatures on ordinary chemical action. Instead of being reduced, the emission of heat, so far as present data can be relied on, is augmented at the temperature of liquid hydrogen. Whatever be the nature of this extraordinary phenomenon, it only increases in intensity at a point where all but the most powerful chemical affinities are in abeyance. The evaporation of a liquid gas gives an absolute measurement of the amount of heat given off by radium. Changes in the degree of radio-activity may escape the most careful observer, or may be imagined where they do not exist, but the quantity of liquid hydrogen which a given mass of radium converts into gas in a given time can be easily measured with an accuracy

which is beyond cavil, and the amount of heat required for the conversion can be ascertained with great precision. Hence there is no longer any doubt either of the quantity of heat evolved by radium or of the fact that the rate of emission is apparently greater in liquid hydrogen than at any temperature from that of liquid air up to that of an ordinary room. At the beginning of these experiments in liquid hydrogen a contrary result appeared to emerge when the low-temperature thermal measurements were compared with the early Curie values observed at the temperature of melting ice, as formerly given in The Times. This led to the curious discovery that a freshly prepared salt of radium has a comparatively feeble power of giving off heat at all temperatures, but that its power steadily increases with age until about a month from its preparation, when it reaches the maximum activity, which it afterwards maintains apparently indefinitely. A solution of a radium salt behaves in exactly the same way. power of heat-emission is at first relatively low, but goes on increasing for about a month, when it becomes equal to that of the solid salt, and so remains.

Its

MAGNETIC WORK EXECUTED BY THE U. S.
COAST AND GEODETIC SURVEY BE-
TWEEN JULY 1, 1902, AND JUNE
30, 1903.

THE work accomplished during the fiscal year, July 1, 1902, and June 30, 1903, may be summarized as follows:

A. Magnetic Survey Work.-The magnetic elements were determined at 461 stations distributed over thirty-one states and territories, three foreign countries and adjacent seas. The principal work was done in Arizona (54 stations), Florida (26), Kansas (49), Louisiana (15), Maryland (8), Michigan (14), Nebraska (19), Ohio (19), Pennsylvania (52) and Texas (72).

By December of this year, owing to the progress already made, the magnetic survey of the area bounded by latitudes 35° and 41°, and longitudes 75° and 85°, embracing the states of Pennsylvania, New Jersey, Delaware, Maryland, Virginia, West Virginia, Ohio, North