past history of a group by studying its species. If the species are well defined and show elaborate adaptations to the environment the group has long existed under relatively uniform conditions. If, on the other hand, the species are defined with difficulty and connected by numerous races it may be presumed that the environment of the group has changed in recent times, and especially that it is undergoing expansion and differentiation in new territory. In northern regions the retreat of the ice has exposed much such territory; in the Antilles it has been the elevation of the land; in other cases a type may have found new lands by migration, and may thus exhibit incipient new species in the midst of a stable ancient fauna. As an example of the last-mentioned class may be mentioned Danais berenice jamaicensis in Jamaica, as against the old Jamaican type Papilio homerus. We have digressed from the immediate subject of this useful catalogue, but the interest of such works lies largely in the suggestiveness of their orderly and condensed array of facts.

T. D. A. COCKERELL. MESILLA PARK, N. M., February 12, 1899.

Industrial Electricity. Translated and adapted from the French of HENRY DE GRAFFIGNY. Edited by A. G. ELLIOTT, B.Sc. London and New York, The Macmillan Company. Pp. 152. With 65 illustrations. Price, 75 cents. This little volume, according to the editor's note, is the first of a series upon Electromechanics, the other volumes of which will treat the more important of the branches here touched upon, separately and in detail. It is divided into short chapters, and explains, in very clear and non-mathematical language, the various applications of electricity.

Beginning with Nature of Electricity, a résumé of Hertz's work is given, showing the identity of light and electrical vibrations. Then follow, in order, chapters on Electric Units, Magnetism and Induction, and Practical Measurement of Electrical Quantities.

Chapters V. and VI. are respectively on Chemical Generators of Electricity and Accumulators, covering the subjects of primary and storage batteries and containing much useful information and explicit directions as to handling and care.

Dynamo Electric Machinery is next touched upon, including direct current dynamos, alternators, two- and three-phase generators. The remaining five chapters merely touch upon the following subjects: Electric Light, Electricity as a Motive Power, Electro-chemistry and Electro-plating, Bells and Telephones, and Telegraphs.

The only criticisms that can be advanced are: 1. On page 12 the table gives 10'C.G.S. units in one Henry instead of 109, while the table on page 27 has many of the dimensions of the mechanical, electro-magnetic and magnetic unis given incorrectly.

2. Besides these lapses the volume is, with one or two exceptions, entirely devoid of allusions to American apparatus and machinery.

Taken as a whole, however, the volume is a creditable piece of work, for the task of condensing so much in so small a space is, to say the least, herculean. W. H. F.

GENERAL.

THE Teachers' Professional Library, edited by Professor Nicholas Murray Butler, of Columbia University, is announced by The Macmillan Co. The books already published on 'The Development of the Child,' by Dr. Nathan Oppenheim; 'The Study of Children and their School Training,' by Dr. Francis Walker, and a 'Handbook of Nature Study,' by O. Lange, are included in the series and the following are announced for early publication:

"The Practical Lessons of History,' by William T. Harris, LL.D., U. S. Commissioner of Education.

'Social Phases of Education in the Home and in the School,' by Samuel T. Dutton, Superintendent of Schools, Brookline, Mass.

'Educational Aims and Educational Values,' by Dr. Paul H. Hanus, Harvard University.

'The Hygiene of the School and of Instruction,' by Edward R. Shaw, Ph.D., New York University. 'Method in Education,' by Walter L. Hervey, Ph.D., Department of Education, New York City. 'The Study and Teaching of History,' by Miss Lucy M. Salmon, Vassar College.

'The Study and Teaching of Geography,' by Dr. Jacques W. Redway, of New York.

"The Study and Teaching of English,' by Percival Chubb, of the Ethical Culture Schools, New York. 'The Study and Teaching of Mathematics,' by

David Eugene Smith, Ph.D., State Normal School, Brockport, N. Y.

IT is announced that the government has compiled a History of the Territory of Alaska, bringing the explorations made by army officers up to date and including an elaborate description of the physical resources of the Territory. The compilation when published will make a large octavo volume of about 500 printed pages. The material was supplied, by the War Department under the direction of Assistant Secretary Meiklejohn, to the Senate.

BOOKS RECEIVED.

General Physiology. MAX VERWORN. Translated from the second German edition and edited by FREDERIC S. LEE. New York and London, The Macmillan Company. 1899. Pp. xvi +615. $4.00. L'audition et ses organes. M. E. GELLÉ. Paris, Alcan. 1899. Pp. 326. La Céramique ancienne et moderne. E. GUIGNET and EDOUARD GARNIER. Paris, Alcan. 1899. Pp. 311.

The Theory of the Leisure Class: an Economic Study in the Evolution of Institutions. THORSTEIN VEBLEN. New York and London, The Macmillan Company. 1898. Pp. vii +400. $2.00.

SCIENTIFIC JOURNALS AND ARTICLES. THE American Mathematical Society is actively pushing the plans for the publication of its Transactions, and it is probable that the first number will appear in January next. A committee, consisting of Messrs. T. S. Fiske, R. S. Woodward, E. H. Moore, Maxime Bôcher and James Pierpont has been appointed to secure the necessary financial guarantees. Subscriptions of one hundred dollars annually for a term of five years have already been pledged by representatives and friends of each of the following institutions: Chicago University, Columbia University, Yale University and Bryn Mawr College. Other pledges are anticipated and the plan is already assured of success.

The Journal of Geology, Vol. 7, No. 1, for January and February, contains the following papers:

Frank Leverett: The Lower Rapids of the Mississippi River,' pp. 1-20. The writer discusses the abandonment by the Mississippi River of its pre glacial channel just above Keokuk, Ia., and the production of the newer and

more contracted channel, in which are the rap · ids. The Kewatin ice sheet and its drift are regarded as the principal cause.

H. B. Kümmel: The Newark Rocks of New Jersey and New York,' pp. 23-53. The writer divides the strata under consideration into the Stockton, Lockatong, Brunswick and Trap formations. Their distribution, character, folding and faulting, and the conditions prevailing during their formation, are then discussed.

Henry S. Washington: The Petrographical Province of Essex County, Mass.,' II., pp. 53– 64. The paper continues one that was begun in the last number. It describes, with analyses, the essexites, diorites, quartz-augite-diorites, porphyritic diorites and gabbros.

J. A. Udden: 'The Sweetland Creek Beds,' pp. 65-79. The beds are chiefly shale, and lie between the Cedar Valley Limestone below and the Coal Measures above, in Muscatine county, Ia. Fossils indicate an Upper Devonian Age.

G. H. Squier: 'Studies in the Driftless Region of Wisconsin,' pp. 79-83. One glaciated boulder has been found in a valley within the driftless region.

W. N. Logan: 'A Discussion and Correlation of certain Subdivisions of the Colorado Formation,' pp. 83-92. The paper discusses and correlates the subdivisions of this formation in the Kansas, Colorado, Black Hills and Iowa-Nebraska areas.

6

Editorials and reviews complete the number. THE leading article in the American Naturalist for February, is by Dr. W. H. Dall, and discusses The Proposed University of the United States and its possible Relations to Scientific Bureaus of the Government.' Dr. Arthur Hollick continues the consideration of 'The Relation between Forestry and Geology in New Jersey,' this paper giving 'The Historical Development of the Flora,' concluding that the gradual extinction of the gymnosperm type is indicated. Professors J. H. Comstock and J. G. Needham also continue the subject of 'The Wings of Insects,' the chapter being devoted to the specialization of wings by addition as illustrated by the venation of the wings of Ephemerida. Under the title of The Peneplain a Review' Dr. R. A. Daly considers at length Professor Tarr's objections to the exist

ence of peneplains on this earth of shifting base levels. Professor F. L. Washburn describes and figures the shoulder girdle of A Peculiar Toad,' presenting the abnormality of an extra (left) fore limb. The abundant literature on the subject of the Trenton Gravels receives an addition from Dr. Frank Russell, who describes some 'Human Remains from the Trenton Gravels,' concluding that the skulls which are figured are those of modern Indians, probably of the Lenni Lenapé. A goodly proportion of Notes and Reviews fill out the number.

เ

THE Journal of the Boston Society of Medical Sciences for January comprises two parts, each containing a number of excellent plates. Those illustrating the articles on the Pathological Histology of Acute Lacunar Tonsilitis,' by J. L. Goodale, and the 'Character of the Cellular Exudation in Acute Keratitis of the Rabbit,' by W. T. Councilman, are particularly fine. Our anti-vivisection friends who discredit the exist ence of hydrophobia would do well to read the paper by Langdon Frothingham on 'Rabies in the Vicinity of Boston,' where 20 positive cases are noted between March, 1897, and December, 1898. An interesting series of 'Observations on the Effects Produced by the 6-mm. Rifle and Projectile,' by H. G. Beyer, is well calculated to create respect for the new Navy arm.

THE Botanical Gazette for February contains the following leading articles: 'New or Little Known North America Trees,' C. S. Sargent 'The Ecological Relations of the Vegetation on the Sand Dunes of Lake Michigan,' Henry C. Cowles; 'The Society for Plant Morphology and Physiology-Columbia Meeting,' W. F. Ganong. The briefer articles include: 'Notes on the Maximum Thermal Death-point of Sporotrichum Globuliferum,' B. M. Duggar; ‘Descriptions of Two Willows from Central America,' W. W. Rowlee; 'A Peculiar Case of Spore Distribution,' F. L. Stevens; 'A New Silphium,' Wm. M. Canby.

SOCIETIES AND ACADEMIES.

SECTION OF PSYCHOLOGY AND ANTHROPOLOGY OF THE NEW YORK ACADEMY OF SCIENCES.

AT the regular monthly meeting of the section, on February 24th, papers were presented

by R. S. Woodworth on the 'Accuracy of Movement, by F. C. Spencer on the 'Origin and Persistent Influence of Sacred Number Concepts,' and by F. Boas on 'Anthropometric Charts.'

Dr. Boas presented the results of recent investigations, which show that the anthropometric charts now used in the gymnasium by anthropologists are valueless as a means for estimating the development of individuals. CHAS. B. BLISS,

Secretary.

ONONDAGA ACADEMY OF SCIENCE.

AT the January meeting annual reports of officers and sections were received and the following officers were elected: President, John Van Duyn, M.D.; Vice-President, J. A. Dakin; Secretary, P. F. Schneider; Corresponding Secretary, H. W. Britcher; Treasurer, Miss L. W. Roberts; Librarian, Miss V. L. Jones.

The report of the Geological Section showed considerable progress in the investigation of interesting local problems, and cited the discovery of a vein of quartz crystals in the Corniferous rock at the Onondaga Indian Reservation.

The report of the Botanical Section included new localities for several of the rarer plants of the county. One plant, Glaucium glaucium, was reported as new to the county, and two, Crepis virens and Sanguisorba canadensis, were reported as new to the State. Selaginella selaginoides was also found and is probably new to the State.

The report of the Zoological Section contained the result of feeding experiments on the larvæ of Diedamia inscripta. During the year upwards of thirty spiders were added to the Of these, list of Onondaga county species. nine species had not hitherto been reported in the State. H. W. BRITCHER,

DISCUSSION AND CORRESPONDENCE,
WHAT IS THE CAUSE OF THE SO CALLED
TOBACCO FERMENTATION?

THUS far it has been generally believed that the rise of temperature and the chemical changes that take place when the cured tobacco leaves are piled up in heaps are due to bacterial action. But careful investigations of the 'fer

menting' leaves revealed the absence of extended bacterial colonies, the presenc of which were naturally to be expected if bacteria were the cause of the phenomena in question. The true cause, I have recently established beyond a doubt, is the presence of two kinds of oxidizing enzymes in the tobacco leaves. As soon as the Bulletin describing these investigations is published a full review will be given in this JOURNAL. OSCAR LOEW.

DIVISION OF VEGETABLE PHYSIOLOGY AND PATHOLOGY, U. S. DEPT. OF AGRICULTURE.

THE ANÆSTHETIC EFFECTS OF A SINUSOIDAL CURRENT OF HIGH FREQUENCY.

TO THE EDITOR OF SCIENCE: In your issue of June 3, 1898, I had the honor of communicating an observation on the anæsthetic effects of a sinusoidal current of high frequency. I take the liberty of sending you the following further observations.

a. The anaesthetic effect may be produced by sending the current longitudinally along the the nerve. Thus, a current sent along one of the nerves of the arm can be used to produce anæsthesia in parts of the arm supplied by it. With a pleasant current of about 28,000 alternations per second passing between the elbow and the hand, a needle can be painlessly run into the forearm.

b. At the suggestion of Professor B. Moore, of the Yale Medical School, I applied the current to the tongue, with a view to testing the theory that the sensation of taste may be due to vibratory stimuli. If the theory were true the fluctuations in the sinusoidal current might be expected to produce sensations of taste of various kinds. The experiment showed that fluctuations up to about 29,000 complete periods per second produce no sensations of taste whatever; the only sensation is that of tickling and puckering.

c. It should perhaps have been stated in my original communication that the main purpose of the investigations with the sinusoidal current was to determine the various sensations at different frequencies. They have been determined for two subjects as follows: (1) Threshold of sensation of touch at a frequency of about

480 complete alternations per second; (2) threshold of disagreeableness at about 840; (3) threshold of pain at about 960; (4) disappearance of pain at about 1,440, followed by a peculiar, agreeable sensation; (5) disappearance of agreeableness at a point not yet determined, followed by a faint sensation; (6) disappearance of sensation at a point not yet determined. For constant conditions these figures are quite constant, the probable error ranging from of 1 % to 4 %.

d. Applying the electrodes to the nerves of the arm in a way to move the muscles of the forearm and hand I find a similar neuromuscular effect. As the current rises in frequency from zero the muscles contract steadily up to a certain point, after which they gradu. ally relax. The process is the same when we start with a high frequency and descend to zero. The phenomenon can hardly be due to a diminished intensity of the high-frequency current.

e. It may be added that the instrument used is a Kennelly alternator run at a very high speed. Similar high-frequency machines have been used by Nikola Tesla, who has not recorded any of the above phenomena; possibly his machines do not produce sinusoidal currents. f. Using another machine which simply interrupted a galvanic current up to 100,000 times per second I find that above a certain point (not yet measured) the interruptions cease to have any effect other than merely reducing the strength of the current when it is sent through the tissues.

E. W. SCRIPTURE. YALE UNIVERSITY, NEW HAVEN, CONN., February 28, 1899.

NOTES ON PHYSICS.

THE METRIC SYSTEM.

THE Hartford Steam Boiler, Inspection and Insurance Company of Hartford, Conn., has issued a very neat and convenient volume, of 'pocket size,' containing tables for the Conversion of English weights and measures into their metric equivalents, and vice versa. It opens with a very interesting discussion of the metric system, which lacks, however, any recognition of the International Bureau of Weights and

Measures and the great work it has accomplished during the past twenty-five years. Nothing is said about the International Prototype units of length and mass, which are the real standards of the world to-day, and it is implied that the meter and kilogramme are, except for practical purposes, what they were defined to be a hundred years ago. The ratios of the metric to our customary units used, in the book, are not those legally adopted by the U. S. Office of Weights and Measures, but the differences are so small that the conversion tables are not sensibly in error. There is a growing use of the metric system in this country, the result of an increasing trade with foreign countries, and this book will satisfy every demand of those who are called upon to convert from one system to the other. The tables are so numerous that it is difficult to imagine a call for anything which the book does not contain, and a convenient index renders them quickly available. Much time is saved by carrying the tables up to one-hundred multiples of each unit, but in a few instances space and labor have been wasted in doing this, because of the impossibility of such conditions ever being realized. For instance, in the table for converting 'grammes in a cubic centimeter to ounces in a cubic inch,' there does not appear to be any necessity for going beyond 23 or 24as there is no known substance denser than this. Thus more than three-quarters of this table can be of no use, and this is true of several tables of a similar character. On the whole the work is exceedingly well done, and the book ought to be much sought after. T. C. M.

THE

ELECTROLYTIC INTERRUPTER FOR THE
INDUCTION COIL.

WHEN a high electro-motive force is connected to an electrolytic cell, one electrode of which is very small, the rush of current which takes place is quickly interrupted by the layer of gas which is generated at the small electrode. This layer of gas then collects as a bubble, the electrolyte again comes into contact with the electrode, a rush of current again takes place to be interrupted as before, and so on. These interruptions are very abrupt, and their frequency varies from two or three hundred to a thousand or more per second according to the size of the

small electrode and the inductance of the circuit. The small electrode should be the anode.

Dr. A. Wehnelt (Electrical Engineer, February 16, 1899) has applied this electrolytic interrupter to the induction coil. He uses dilute sulphuric acid, a sheet of lead as cathode, and the tip of a small platinum wire projecting from a glass tube as anode. The interrupter works with entire satisfaction with electro-motive forces as high as 110 volts; the condenser, needed with the ordinary interrupter, is useless; and the effectiveness, especially of small coils, is greatly increased both in length of spark and frequency.

Dr. Wehnelt's experiments have been repeated in the Physical Laboratory at Bethlehem Pa., his results have been confirmed, and it has been found that the primary of an induction Icoil should be wound with more turns of wire than usual to give the best results with this electrolytic interrupter. The interrupter gives good effects when used to supply intermittent current to the primary of a small transformer. Thus a small step-down transformer taking 375 watts from the mains gave out about 30 watts from its secondary.

When the electrolytic interrupter is used to supply intermittent current from a 110 volt source to the primary of a transformer, the e. m. f. which establishes the current after each break is, of course, 110 volts, while the e. m. f. which stops the current is the e. m. f. between the break points and may be very greatly in excess of 110 volts.

The effective primary e. m. f. is, therefore, on the whole, greatly in excess of 110 volts, so that a 1:1 transformer may give several hundreds of volts at its secondary terminals when supplied with intermittent current from a 110 volt source.

This is shown by the fact that a 220 volt lamp, for example, may be lighted from the secondary, and, of course, it may be lighted equally well or even better if connected across the primary terminals. W. S. F.

THE RESISTANCE OF CARBON AND COPPER

BRUSHES.

PROFESSOR E. ARNOLD gives, in the Electrical Zeitschrift for January 5th, a study of the 'Con