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stars were shining brightly to the north. dices. Each volume includes also the alphaThe moon, which was very low in the west betical index of names. (about 15° south of west, with an altitude of The order of treatment of each biography some 5° or 6°), was hidden from view by consists of the following: Life; Works, inbuildings, where I stood; and, because of the cluding a critical discussion of the historical street lights, I was not even aware that the and scientific significance; Bibliography, inmoon was out until the rainbow in the east cluding completo catalogue of all works, with caught my eye. None of the prismatic colors place and date of printing of published works, could be detected, the bow being merely a editions, and translations with precise biblioyellowish arch of light very well defined at graphical descriptions and also some statethe southern end-rather an odd thing to see ment of location in Italian libraries of at that time of night.

volumes mentioned; Literature, giving lists of FRANK L. GRIFFIN works which discuss the work or life of the REED COLLEGE,

scientist in question. PORTLAND, ORE.

The mathematician will welcome the fine

biographical statement (pp. 4–12) concerning SCIENTIFIC BOOKS

Leonardo Fibonacci, written by Gino Loria; Gli Scienziati Italiani, dall'inizio del medio the astronomer will appreciate the excellent

evo ai nostri giorni. Repertorio biobiblio- account (pp. 45–67) of Schiaparelli, by Elia grafico dei filosofii, matematici, astronomi, Millosevich; the geographer and the astronofisici, chimici, naturalisti, medici, e geografi mer will find much of interest in the account Italiani. Diretto da Aldo MIELI, e compiuto (pp. 101–111) of Giovanni Antonio Magini con la collaborazione di numerosi scien- (1555–1617) by Antonio Favaro, who lists no ziati, storici, e bibliografi. Vol. I., Parte I., less than 47 printed works (and editions) by Rome, 1921. Pp. viii +236. A. Nardec- Magini; the student of medical history, the chia, publisher.

botanist and naturalist and the physicist will In the issue of SCIENCE of August 30, 1919, enjoy a whole series of illuminating articles. pp. 213—214, I called attention to Italian Particularly noteworthy is the fact that a activity in the field of the history of science, photograph and a facsimile of handwriting evidenced by the new publication Archivio di is given of each scientist, wherever possible. Storia della Scienza, edited by Aldo Mieli, This publication promises to be a work which journal has now completed its first comparable only to the English Dictionary of year. The present work indicates the con- National Biography; for America, France or tinued and growing interest in Italy in the Germany there is no work of this nature. history of science.

When completed on present plans libraries The first part of this biographical diction- will find it as indispensable as the above ary presents the biographies of thirty-three mentioned dictionary. Italian scientists from the fifteenth to the With the present state of exchange the price present century. The list of contributors to of 45 liras for Part I., viii plus 236 pages, is the volume shows that the great scholars of extremely low. Every effort should be made Italy are devoting themselves to assure the by American scientists, historians, and lisuccess of the present work under the able brarians to encourage the continuation of this editorship of the distinguished historian of publication on the present scale. The effecscience, Aldo Mieli.

tive way to do this is by subscription to the One peculiarity of the work is that neither publisher, A. Nardecchia, Via dell'Universita chronological nor alphabetical order of treat 11-14, Rome, Italy. ment is pursued in selecting the scientists in- The alphabetical list of articles follows: cluded. Eventually, of course, the completed Acri, Francesco (1834–1913), philosopher, by work will be provided with all necessary in- E. P. Lamanna.

[graphic]

Alpino, Prospero (1553-1616) botanist, by Passerini, Giovanni (1816–1893), botanist, by A. Beguinot.

G. B. De Toni. Amici, Giovanni Battista (1786-1863) physi- Piccone, Antonio (1844–1901), botanist, by cist. naturalist, by G. B. De Toni.

G. B. De Toni. Anguillara, Luigi (c. 1512–1570) botanist, by Pontedera, Giulio (1688–1737), botanist, by G. B. De Toni.

A. Beguinot. Baranzano, Redento (1590–1622) philosopher, Riva, Giovanni Guglielmo, (1627–1677), phys astronomer, by G. Boffito.

ician, by O. Artom. Bertini, Anton Francesco (1658–1726), phys Schiaparelli, Giovanni Virginio (1835–1910) ician, by A. Corsini.

astronomer, historian of science, by E.

Millosevich. Bertini, Giuseppe (1772-1845) physician, by

Silvestri, Francesco (1474–1528), philosopher, A. Corsini. Bertini, Giuseppe Maria Saverio (1694-1756),

by G. Sestili. physician, by A. Corsini.

Sterzi, Giuseppe (1876–1919), anatomist, by

G. Favaro. Biringuccio, Vannoccio (1480-1530 ), tech

Valli, Eusebio (1755-1816), physician, by nician, chemist, by A. Mieli.

A. Vedrani. Cestoni, Diacinto (1637–1718), naturalist, by

Zanardini, Giovanni (1804-1878), physician, G. Stefanini.

botanist, by G. B. De Toni. Chiarugi, Vincenzo (1759–1820) psychiatrist,

LOUIS C. KARPINSKI physician, by A. Vedrani.

UNIVERSITY OF MICHIGAN
Cocchi, Antonio (1695–1758), physician, by
A. Corsini.

SPECIAL ARTICLES
Corti, Bonaventura (1729-1813), botanist, by

THE EINSTEIN SOLAR FIELD AND SPACE OF G. B. De Toni.

SIX DIMENSIONS Cotugno, Domenico (1736–1822), physician,

The Einstein theory is four-dimensional in by G. Bilancioni.

the sense that four (general or world) coordiDe Visiani, Roberto (1800–1878), botanist, by

nates Xı, X2, X3, Xs are employed. The fundaA. Beguinot.

mental quadratic form Dini, Ulisse (1845–1918), mathematician, by

ds2 = Egikdxidak, G. Loria. Fibonacci, Leonardo (sec. xii-xiii), mathe- where the ten potentials gik are functions of matician, by G. Loria.

the four coordinates, in general has a curvaFigari, Antonio (1804–1870) traveler, nat- ture tensor which does not vanish, and thereuralist, by G. Stefanini.

fore defines a curved manifold M of four diFolli, Francesco (1624–1685), physician, nat- mensions. In fact M is flat or euclidean or uralist, by G. Goretti-Miniati.

homodoidal only when there is no actual Ghini, Luca (c. 1490-1556), botanist, by G. gravitation. Excluding this trivial case, the B. De Toni.

question arises what is the flat space of fewest Guilandino, Melchiorre (c. 1520-1589), botan- dimensions n, which can be regarded as conist, by G. B. De Toni.

taining the curved manifold M? Inghirami, Giovanni (1779-1851), astronomer, Abstractly considered the possible values of by G. Giovannozzi.

n are 5, 6, 7, 8, 9, 10; that is, any M can surely Magini, Giovanni Antonio (1555-1617), as- be immersed in a flat space of not more than tronomer, geographer, by A. Favaro.

10 dimensions. But if we take into account Maranta, Bartolomeo (c. 1500--1511), phys- Einstein's differential equations of gravitaician, botanist, by G. B. De Toni.

tion, Rik=0, or Gik=0, we find that the Moletti, Giuseppe (1531-1588) astronomer, simplest case, n=5, is actually impossible. cosmographer, by A. Favaro.

That is to say:

An Einstein four-dimensional manifold, defining a permanent gravitational field, can never be regarded as immersed in a flat space of five dimensions.

This applies in particular to the solar field (defined say by the Schwarzschild form), in which the earth and the other planets are moving. The appropriate value of n must therefore be greater than 5 and less than 11. A brief discussion shows that actually n=6. Therefore:

The solar gravitational field can be represented by a curved manifold of four dimensions situated in a flat space of six dimensions.

This manifold can be written in finite form and gives what may be called a geometric model of the field in which we are living.

The proofs of these theorems and the actual equation of this model are appearing in current numbers of the American Journal of Mathematics, together with the full discussion of the general results connecting light rays and orbits in any field stated in SCIENCE, October 29, 1920, pp. 413_414.

EDWARD KASNER COLUMBIA UNIVERSITY

very short

This is probably largely due to a wrong interpretation of the official method. From the standpoint of the manufacturer this is quite a serious matter and it seems desirable that the Association of Offi. cial Agricultural Chemists should take such action as is necessary to modify or at least change the reading of the modified methods so that there may be no misunderstanding of how they should be carried out.

Dicyanodiamide. A rapid, direct method for its determination in cyanamid and mixed fertilizers: ROLLA N. HARGER, presented by Oswald Schreiner. The method depends upon the fact that when a solution of silver picrate is added to a solution of dicyanodiamide, the latter is quantitatively precipi. tated as a double compound of silver picrate and dicyanodiamide, CH,(NO,),0AG, CHN.. This new double compound we have named silver picratemono-cyanoguanidine. It forms in small crystals which quickly settle out of the solution and can be separated upon a Gooch crucible very rapidly, so that the analysis can be carried out in time. Neither cyanide nor urea give any precipitate when their solutions are treated with silver picrate, and determinations of dicyanodiamide carried out in the presence of these compounds showed that they have no effect upon the analysis. The molar weight of the compound is 420.22, five (4.991) times that of dicyanodiamide, a fact which greatly enhances the accuracy of the method, since an error of 1 mg. in the precipitate weighed will mean an error of only 0.2 mg. of dicyanodiamide or 0.13+ mg. of nitrogen.

The changes taking place in cyanamid when used in mixed fertilizers: RoLLA N. HARGER, presented by Oswald Schreiner. (1) When cyanamid is placed in a mixed fertilizer containing acid phosphate and 5–10 per cent. of moisture, the cyanamide content decreases with great rapidity. (2) This change is represented principally by, and in many cases quantitatively by, the formation of dicyanodiamide. (3) A given quantity of moist acid phosphate is able to transform a limited amount of calcium cyanamid. (4) Cyanamid is not affected by dry acid phosphate. (5) Moisture alone is able to cause the conversion of cyanamid to dicyanodiamid, but the change is much slower than when acid phosphate is present. Since it has been repeatedly shown that dicyanodiamid is valueless as a fertilizer material and, moreover, is toxic to many plants, the formation of this compound in fertilizer materials seems undesirable. From the results of this study it would seem that

THE AMERICAN CHEMICAL SOCIETY

(Continued)

FERTILIZER DIVISION

F. B. Carpenter, chairman

H. C. Moore, secretary Kelp as a basis of an American potash industry: J. W. TURRENTINE.

Relationships of chemistry and the fertilizer industry: C. H. MACDOWELL.

A perfect fertilizer law: E. G. PROULX.

Boron in relation to the fertilizer industry: J. E. BRECKENRIDGE.

The quantitative estimation of borax in mixed fertilizers: J, M. BARTLETT.

Note on the determination of nitrogen in fertilizers containing both organic and nitric nitrogen: F. B. CARPENTER. Notwithstanding the fact that the modified Kjeldahl and Gunning methods have been in use for a number of years, the results obtained by these methods in the hands of different analysts on samples containing mixtures of organic and nitric nitrogen are far from satisfactory.

the method of applying cyanamid, commonly em- where as much as 400 pounds per acre was used ployed, which consists in adding the cyanamid to with apparently no bad results. Experiments made fertilizer mixtures containing acid phosphate, by the writer on corn, beans, cotton, Irish potatoes, which mixtures almost always contain several per sweet potatoes and tobacco showed no bad effects cent. of moisture, is a very questionable practise. where 8 pounds anhydrous borax per acre were Moreover, the use of cyanamid as a "conditioner" used, but there was slight injury with sixteen for green” acid phosphate is very probably at pounds. It is evident, therefore, that the character the expense of most of the nitrogen in the cyana- of soil, amount and time of rainfall, the manner mid. On first thought it would appear that this of application, etc., influence to a large degree the conversion of cyanamid into dicyanodiamide could amount of borax which can be used without poisonbe avoided by simply employing dry fertilizer mix

ous effect. tures, but this overlooks the fact that when such

The "blankin the Kjeldahl process; its analytmixtures are added to the soil moisture conditions

ical and commercial significance : B. F. ROBERTSON. are at once provided and the transformation may

Potash shales of Illinois: M. M. AUSTIN and S. possibly then take place. Preliminary experiments

W. PARR. (1) Shales occur in at least two localities carried out in this laboratory indicate that under

in Illinois which contain five per cent. or more of certain conditions at least this is the case.

potash. (2) Shale outcropping in several places Some results of the determination of potash by near Jonesboro in Union County which contain the Lindo-Gladding method, using alcohol of vari- five per cent. of potash would be suitable, so far as ous strengths in the presence of sodium salts: R. D. can be determined from its chemical composition CALDWELL and H. C. MOORE. When potash is de- and physical character, for use in the manufacture termined by the official method of the A. O, A. C. of Portland cement. (3) By using this material in but slightly lower results are obtained when 80 the manufacture of cement and by applying the per cent, alcohol is used than when 92 or 95 per known methods of potash recovery, a yield of 5.3 cent, is used in case of sample of pure potassium pounds of potash, representing a value of 70 to 80 chloride, but when sodium chloride or sulfate is cents per barrel of cement could be obtained. (4) added the results with 80 per cent, alcohol are The constitution of the southern Illinois shale is lower. Tests with a sample of potassium platinic complex. The shale contains free oil, bituminous chloride showed it to be but slightly soluble in 80 matter, pyrite, undecomposed potassium bearing per cent, alcohol alone, but the solubility increases rock, feldspathic in character and potassium bearwith the increase of sodium salts added but with ing material of the nature of glauconite or green95 per cent, alcohol sodium salts have no effect. sand. (5) Shale from Dixon, Lee County, contains

Injurious effects of borax on field crops: F. B. 5.8 per cent. of potash which is held for the most CARPENTER. It has long been known that certain part in a more stable condition than that in the chemical substances are poisonous to plant life.

southern Illinois shale. (6) Extraction of the poWhile certain compounds of copper, zinc and ar

tassium from shale of either the southern Illinois senic are exceedingly poisonous, compounds of

or Dixon type by means of solid or liquid reagents manganese and boron are far less deleterious. would seem to be impracticable, because of the inMost of the experiments which have been made complete reaction of these reagents on the shale with these compounds have been made on plants

and because of the cost of leaching and recovering grown in pots or water cultures; in case of borax, potash from material where it is present in such however, considerable knowledge has been gained

small amounts. (7) The plant availability of the during the past few years on field crops from the

potash in the southern Illinois shale is probably use of Searles Lake potash, which contained an

characteristic of all of the material of this type oxcessive amount of this compound. The first outcropping in that locality. (8) That part of large scale borax poisoning in this country occurred the potassium in the southern Illinois shale which in Indiana in 1917 on corn. In 1919 considerable is soluble in sulphuric acid, is shown to be in a damage was reported on potatoes and tobacco in combination of the glauconite type. (9) In southdifferent localities. Many conflicting reports were

ern Illinois shale having a potash content of 5.0 made in regard to amount of borax required to per cent, in the raw condition or 5.6 per cent. when produce injury. While in some instances as little ignited, 62 per cent. of the total potash is glauas two pounds per acre has been reported to have

conitic in character and is available as plant food. slightly injurious effects, one report was noted Potash situation in Germany: H. A. HUSTON.

sults obtained, and the conclusions drawn from them, compare favorably with other results obtained with ammonium salts.

Method for the determination of free sulfur and antimony tri- and penta-sulfides in golden antimony: J. F. SCHUFTER.

RUBBER DIVISION
W. K. Lewis, chairman

Arnold H. Smith, secretary
Reports.

Discussion: Shall the Rubber Division publish an annual volume of reprints and lengthy abstracts of everything of interest to the rubber chemist made public during the year?

Election of officers.
Rubber energy: W. B. WIEGAND. (Lantern.)

The aging of some rubber compounds : New Jersey Zinc Co. Research Laboratories. (Lantern.)

Some microsections cut from vulcanized rubber articles: New Jersey Zinc Co. Research Laboratories. (Lantern.)

The action of certain organic accelerators in the vulcanization of rubber. II.: G. D. KRATZ, A. H. FLOWER and B. J. SHAPIRO. The relative activities of molecularly equivalent amounts of aniline and diphenylthiourea in the acceleration of vulcaniza. tion were compared in rubber-sulfur mixtures and in mixtures which contained zinc oxide. In a rubber-sulfur mixture the activity of aniline was found to be much greater than that of diphenylthiourea. In mixtures which contained zinc oxide, the reverse was true. With aniline as the accelerator, either in the presence or absence of zinc oxide, the same maximum tensile strength was obtained, accompanied by a higher sulfur coefficient in the absence of zinc oxide than when this substance was present. The mixtures which contained zinc oxide, attained the same maximum tensile strengths at approximately the same sulfur coefficients, irrespective of whether aniline or diphenyl. thiourea was employed as the accelerator. It is evident that there is apparently no general relation between the physical properties and sulfur coefficients of accelerated mixtures.

The action of certain organic accelerators in the vulcanization of rubber. (II.): G. D. KRATZ, A. H. FLOWER and B. J. SHAPIRO. The activities of certain synthetic, nitrogenous organic accelerators, in a mixture of rubber and sulfur, were compared with the dissociation constants of the original substances. With the exception of members of a closely related series, no definite relation was found to exist between the activities of the substances as accelerators and their dissociation constants. Substances which decompose, or react, with other components of the mixture to form substances of acid character do not accelerate unless a neutralizing base, or salt, is present. The re

The action of heat and light on vulcanized rubber: J. B. TUTTLE. The action of heat and light on vulcanized rubber is frequently spoken of as being identical and oxidation is said to be the cause of the deterioration. From published and unpublished tests it is shown that the action of heat is one of change in the rate of the chemical reaction between rubber and sulfur and goes on throughout the entire mass, whereas the action of light is one of oxidation, taking place on the surface. Heat produces no change in the solubility of the rubber substance in solvents such as acetone and alcohol, whereas light breaks up the rubber molecule forming decomposition products which are readily soluble in acetone. · A theory of vulcanization based on the formation of polysulphides during vulcanization: WINFIELD Scott and C. W. BEDFORD. All organic accelerators and a number of inorganic accelerators function as catalysts of vulcanization through the formation of polysulphides. These accelerators may be placed into two classes: (1) Hydrogen sulphide polysulphide accelerators. Organic bases are believed to form polysulphides by the aid of hydrogen sulphide. Examples are piperidene and dimethylamine which form polysulphides in the presence of hydrogen sulphide and sulphur. Inorganic bases, such as sodium hydroxide, calcium hydrate, magnesium oxide and basic magnesium carbonate, function in the same manner as the above. (2) Carbo-sulph-hydrol polysulphide accelerators. Thio ureas and dithiocarbamates are believed to form some type of polysulphides through the grouping C-SH. Differentiated from the above two classes of accelerators are such accelerators as zinc oxide and litharge which do not form polysulphides. These are termed "secondary accelerators' owing to the fact that they decompose polysulphides to give active sulphur.

DIVISION OF WATER, SEWAGE AND SANITATION

J. W. Ellms, chairman

W. W. Skinner, secretary Water softening for the manufacture of raw water ice: A. S. BEHRMAN. The manufacture of

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