when the widespread occurrence of the alkaline rocks is considered.

Table III gives the analyses of a number of these alkaline orthogneisses. The examples cited belong to the alkali granites, the alkali syenites, and the nepheline syenites, the last named being the most numerous. The Van Nest Gap rock belongs to the alkali syenites.

99.56

99.76 99.90 101.19 99.54 100.66 99.84 99.73

1. Alkali quartz-syenite gneiss (akerose). Van Nest Gap, N. Y. Dr. J. E. Wolff, analyst.

2. Arfvedsonite gneiss, Cervadaes, Alemtejo, Portugal. H. Rosenbusch, Elemente der Gesteinslehre, p. 620.

3.

Aegirine-nepheline gneiss. From near locality "2". Ibid.

4. Riebeckite gneiss. Near Gloggnitz Austria. Ibid.

5. Umptekite gneiss (astochite gneiss). West Greenland, Ibid.

6.

Canadite gneiss (miaskose). Lille Elringe, Almunge, Sweden. P. Quen

sel, Bull. Geol. Inst. Upsala, vol. 12, p. 190, 1914.

7. Nepheline-syenite gneiss (viezzenose). Makarainga, Madagascar. A. Lacroix, Comptes Rendus, vol. 155, p. 1125, 1913.

8. Augite-syenite gneiss (akerite). Loon Lake, N. Y. H. P. Cushing, Bull. Geol. Soc. America, vol. 10, 179-192, 1899.

Summary.

1. An alkaline gneiss from the pre-Cambrian of New Jersey is described with regard to its megascopic and microscopic characters.

2. Chemical analysis shows this rock to be an alkaline quartz syenite gneiss belonging to the subrang akerose, in the norm classification, and to the family granodiorite, in the quantitative mineralogical classification of Johann

sen.

3. While the exact geological relations of the Van Nest Gap rock are unknown, its chemical composition place it with the dark colored variety of the Byram member of the New Jersey pre-Cambrian gneisses.

4. The Byram gneiss is considered to be an igneous rock in which foliation developed in the magma during the process of crystallization.

5. Alkaline gneisses from other localities are cited, and the scarcity of this type of foliates is emphasized.

Mineralogical Laboratory,

Harvard University.

SCIENTIFIC INTELLIGENCE

I. CHEMISTRY AND PHYSICS.

1. The Double Decomposition of Salts in Connection with the Phase Rule. Two or three years ago it was announced by ETIENNE RENGADE that in accordance with the phase rule a small quantity of water acting upon an excess of two salts with four different radicals or ions would necessarily cause the appearance in the solid condition of a third salt, one of the two other possible combinations of the ions. In contradiction to this statement Ravenau has recently stated that a mixture of NaNO, and NH ̧Cl could exist without decomposition in the presence of a small quantity of water. Rengade has now shown, however, that this statement is incorrect, for he has found, both by microscopie examination and by analysis of the products of the treatment, that crystals of NaCl are formed in this case. He has found that NHI,NO, and NaCl give NH4Cl as the third solid product, so that there are at ordinary temperature two ternary mixtures containing these four ions:

and

NaNO3 + NH,Cl + NaCl
NH ̧NO2 + NaCl + NHCl.

He states that these can exist without change in contact with a small quantity of water, and that every other mixture of two, three or four of the salts containing the four ions will decompose, giving, according to their proportions, one or the other of the triple mixtures.

Rengade admits, however, that it is possible for two salts with different ions to remain in equilibrium without the formation of a third salt in the solid state. This is the case when the two salts are considerably less soluble than those formed by double decomposition. Consequently it is to be observed that his original

statement is incorrect, but he maintains that the exceptions to it are fully in accord with the phase rule.-Comptes Rendus, 172, 60.

H. L. W.

2. A Comparison of the Atomic Weights of Terrestrial and Meteoric Nickel.-About ten years ago it was shown by Baxter and Thorwaldsen that the atomic weight of meteoric iron is identical with that of terrestrial iron within the limits of experimental error. In view of the recent interest in isotopic elements, such as ordinary lead and the kinds of lead produced by radioaction transformations, G. P. BAXTER and L. W. PARSONS have compared the atomic weights of terrestrial and meteoric nickel. They have very carefully prepared nickel oxide, NiO, from the two sources, the meteoric nickel having been obtained wholly from the Cumpas meteorite found in 1903 near Cumpas, Senora, Mexico. They analyzed the samples of oxide by reduction when heated in hydrogen, and having made corrections for the minute amounts of occluded nitrogen and oxygen contained in the products, they found as averages 58.70 for the atomic weight of the terrestrial nickel and 58.68 for that of the meteoric nickel, where the difference is within the limits of experimental error. There is no evidence from these results, therefore, that there is any isotopic difference between the two kinds of nickel.-Jour. Amer. Chem. Soc., 43, 507.

H. L. W.

General and Industrial Organic Chemistry; by ETTORE MOLINARI. Translated from the Third Enlarged and Revised Italian Edition by THOMAS H. POPE. Part I. Large 8vo, pp. 456. Philadelphia, 1921 (P. Blakiston's Son & Co. Price $8.00 net).-Two English editions of the inorganic part of this treatise have already received very favorable comment in this department of the Journal, and it is evident that the excellent and unusual features of that portion of the work are well shown in the volume under consideration. The author has aimed to bring about a reform in chemical instruction by strongly emphasizing the practical applications of the science in connection with the study of the theory. It appears that the plan offers great advantages in arousing the interest of the student and in training him well for a career in industrial work. Aside from its use as a text book, the work is a valuable one for reading and reference in connection with industrial processes and statistics of costs and production.

This first section of the organic part of the work deals chiefly with the aliphatic compounds, but it does not include the carbohydrates, nor does it describe the soap-making industry. Among the industries rather extensively treated here are those of petroleum, illuminating gas, explosives, and alcohol together with alcoholic beverages. The last subject is extensively treated, but there is a long foot-note giving strong arguments in favor of alcoholic abstinence.

H. L. W.

4. A Treatise on Chemistry, by RoscoE and SCHORLEMMER. Vol. I, The Non-Metallic Elements. 8vo, pp. 968. Fifth Edi

tion, Completely Revised, by J. C. CAIN. London, 1920 (Macmillan and Co., Limited).-It is a pleasure to welcome a new edition of this important work which has served many of our older chemists since their younger days as a valuable source of reading and reference, for the first edition appeared in 1877. The beautiful portrait of John Dalton, the frontispiece, as well as many other illustrations are very familiar, having been retained in all the editions; but while the present editor, as he says, has reverently preserved the general character and style of the book," it appears to have been very well brought to the present time. There have been many additions to our knowledge of the non-metallic elements and a gain of 199 pages in the size of the book since the time of the first appearance of this volume, but it is found that the present edition is only thirteen pages larger than the last one of 1911. The book is so well known that further comments upon its character and excellence seem to be

unnecessary.

H. L.. W.

5. Musical Sands.-CECIL CARUS-WILSON has been interested in musical sands for a long time and has published several communications on the subject. He distinguishes two types of these sands according to the place of their occurrence: 1°, Desert sands such as are found at Jebel Nagous in the desert of Mt. Sinai and 2° Beach sand, of which the earliest recorded example was found on the Island of Eigg. The phenomenon reported in the first kind is as follows: When a disturbance was started in the upper layers on a slope the loose sand thus set in motion rolled down in widening lines like the spread of ripples from a disturbance on the surface of water. This was accompanied by a fluctuating musical sound described as partaking of the character of the note of a mellow church bell and sometimes it was like that of a stringed instrument.

The beach sands on the other hand are said to emit a staccato note under a footfall or when struck with a plunger of wood or brass. The author thinks that these notes are produced by the intermittent slipping and rubbing between clean and well rounded grains of quartz of nearly uniform size, free from roughness, sharp angularities, or adherent matter; apparently having in mind the stuttering motion of slate pencil upon a school slate, or the similar effect in the case of the wetted finger when rubbed on the edge of a tumbler. The vibrations thus started in the sand. or in the striking body, are ultimately elevated into a musical note. In support of this view Mr. Wilson has shown that the highly musical Eigg sand may be rendered mute by adding a certain quantity of dust or angular grains, and on the contrary, certain sands which were not previously musical may be made to emit notes after eliminating dust or angular grains.

The author's experiments were made only on beach sands and consisted chiefly in striking a sample of sand contained in a receptacle such as a porcelain cup which was found to be most suitable. The musical sound emitted depended upon the nature

and the size of the striking body or plunger, which would indicate that the latter acted as a resonator in compressural vibration, taking up the vibrations started by the rubbing grains. In cups of other materials, such as a paste-board box, a flower pot, or a rubber vessel, the sand was mute. Although this point was not mentioned it might be surmised that the porcelain was most suitable because its glazed surface more nearly approximated that of quartz than the other surfaces.

The author has no theory to offer in explanation of the origin of the note in the motion of desert sands and it is difficult to see how the granules should possess a period of vibration slow enough to account for the pitch of the sound observed.

A possible explanation may be found in the idea suggested by Osborne Reynolds (Phil. Mag. 20, 469, 1885) that a mass of grains in coming to rest will take up an arrangement of minimum volume. When, however, they are disturbed the group may pass through many successive minima of volume and if these minima occur at approximately constant intervals of time the accompanying change of volume might conceivably transmit a periodic compression to the surrounding air and thus produce a musical sound.-Discovery 5, 156, 1920.

6. The Electric Furnace; by HENRI MOISSAN. Pp. xvi, 313. Easton, Pa., 1920 (The Chemical Publishing Co.). This is a second edition of the translation of the author's Le Four Electrique, Paris, 1897. the first edition having appeared in 1904. No attempt has been made to add in any way to the text of the original French edition. The work is divided into four rather long chapters which deal respectively with the description of Different Models of Furnaces, the Various Modifications of Carbon, the preparation of ten Elements in the Electric Furnace such as chromium, manganese, tungsten, vanadium, silicon, aluminum, etc., and finally with the preparation of Carbides, Silicides, Borides, Phosphides, Arsenides, and Sulphides.

The work of Moissan is too well known to call for any review. It is the purpose of the publishers to make these classic researches available for all who may wish them. The illustrations of the French text have been reproduced in a manner which may be sufficient for the purpose but nevertheless with the loss of all the artistic value of the originals.

7. Lessons in Heat; by WILLIAM S. FRANKLIN and BARRY MACNUTT. Pp. xi, 147. Bethlehem, Pa., 1920 (Franklin and Charles). This is the third volume of the authors' Lesson Series. The philosophical ideas which underlie the Theory of Heat, such as temperature, quantity of heat, and entropy, are admittedly difficult to grasp and to formulate. The authors' main effort has been to connect up actual things and conditions with the mathematical symbols and this attempt to state the physical essence of thermodynamic principles has been commendably successful. The six chapters take up in succession Thermometry, Calorimetry, Changes of State, Heat Transfer, Properties of Gases and the