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Natural Selection at Fault.

I AM truly sorry if, in my remarks on this subject, I have failed to make myself understood. As regards the common cat, I have seen not merely half-grown kittens, but middle-aged mousers, play with their booty and lose it.

The idea of this practice having the object of cultivating agility seems to me exceedingly far-fetched.

I have not sought to account for the cackle of hens, but have merely pointed out the undeniable fact that it is very liable to attract the attention of any ovivorous bird or beast to the probable presence of an egg.

The rarity in man of the power to erect the ear, or to turn it so as to catch any faint sound-waves has been repeatedly noticed, as also the fact that it does not collect all the impinging sound-waves into the orifice of the ear. My only merit, or demerit (?), has been to cite the abated condition of the ear-muscles as an instance of natural selection at fault. The ear is probably in a state of transition, but in what direction? J. W. SLATER.

London, England, April, 25.

The Habitat and the Diet of the Lepidoptera.

A FEW lepidopterous species select in different countries widely different habitats and food plants. Thus Papilio machaon, the most common European species of papilio, is confined in England to the fenny districts of Cambridgeshire, and occasionally extends to small portions of the adjoining counties. What with the greediness of collectors for "British specimens" of any remarkable insects, and with the drainage of the fields, it is feared that this species will soon be extirpated. The caterpillar of this species, in England, feeds on swamp plants.

In central Europe Papilio machaon is fairly abundant on the dry, gravelly hills and certain parts of lower Silesia, Bohemia and Saxony, the very opposite in their character to the fields of Cambridgeshire. The larva in Silesia and Bohemia feeds frequently on the mountain asb.

The three hawk moths, Chanocampa celerio, Ch. elpenar and Ch. porcellus, on the European continent, feed chiefly upon the vine. But in England they feed on bed straw, willow herb and sometimes on the fuchsia. I have in vain tried to induce larvæ of elpenar or porcellus to feed on vine leaves, probably if the ova had been placed upon vine leaves the young larvæ would have not refused this, their normal food. J. W. SLATER.

London.

Beaver Creek Meteorite.

Between the hours of 3 and 4 P. M. on the 26th of May last, a meteorite was heard by many persons, and three of the fragments were seen to fall near Beaver Creek, West Kootenai District, B. C., a few miles north of the United States boundary.

The two smaller of these fragments, weighing perhaps 5 to 6 pounds in all, were picked up at once; the larger one, weighing about 25 pounds, was not found until the next morning. It made a hole in the wet earth about three feet deep, two feet in soil and one foot in hard pan. The direction of the hole was south 60° east, true meridian, and at an angle of 58° with the horizon. Fresh earth was scattered about the hole in all directions, but farthest (10 feet) in the direction from which the stone came.

On the 6th inst. I saw and purchased this stone from Mr. James Hislop, a civil engineer, who found it and brought it to Washington.

It is a typical aërolite of very pronounced chondritic structure. It is completely coated with the usual black crust, except at one end, where about three pounds have been broken off and scattered, like the two smaller stones, mostly among mere curiosity hunters. The mass now weighs 224 pounds, measures 6 × 7 × 9 inches, and approaches in shape an acute octahedron.

I propose for it the name of Beaver Creek, from the stream by the banks of which it fell.

A microscopical examination and chemical analysis will be
made soon.
EDWIN E. HOWELL.
Washington, D.C.

Delicious

Drink.

Horsford's Acid Phosphate

with water and sugar only, makes a delicious, healthful and invigorating drink.

Allays the thirst, aids digestion, and relieves the lassitude so common in midsummer.

Exchanges.

[Free of charge to all, if of satisfactory character. Address N. D. C. Hodges, 874 Broadway, New York.]

For sale or exchange.-A complete set of the report of the last Geological Survey of Wisconsin, T. C. Chamberlin, geologist. It consists of four large volumes, finely illustrated, and upwards of forty large maps and charts. Will sell for cash or exchange for a microscope. Address Geo. Beck, Platteville, Wis.

For sale or exchange for copper coins or rare postage stamps. Tryon's American Marine Conchology, containing hand colored figures of all the shells of the Atlantic coast of the United States. Presentation copy, autograph, etc. One vol., half morocco, svo, usual price, 52, Postpaid, $15. Botany of the Fortieth Parallel of the Hundredth Meridian of the Pacific R. R. Survey. Other Botanical works and works on Ethnology. F. A. Hassler, M.D., Santa Ana, Cal.

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I have a fire-proof safe, weight 1,10 pounds, which I will sell cheap or exchange for a gasoline teachers wanted for a male and female seminary in central New York. Typewriting, engine or some other things that may happen to etc., languages, mathematics, sciences, et. al. Send suit. The safe is nearly new, used a short time stamp with and for particulars. Box 701, Hemponly. Make offers. A. Lagerstrom, Cannon Falls, stead, L. I.

Minn., Box 857.

dition from the vicinity of Moore's Hill, Ind., also
For exchange.-Hudson River fossils in good con-
land and fresh water shells. Desire fossils and
shells from other groups and localities. Address

sale at low price.-A fine old-fashioned photo

A years' experience in the field is now open to enZOOLOGICAL collector and taxidermist of ten gagement, for either field or laboratory work. References furnished. Address Taxidermist, Box 75, White Sulphur Springs, West Va.

Dr. M. H. Henry, New York, says: Geo. C. Hubbari, Moore's Hill, Ind. "When completely tired out by pro-graphic camera, rosewood box, one foot square. longed wakefulness and overwork, it is lenses, four inches diameter, made by C. G. Harri-WANTED, as principal of a flourishing technical son. Plateholders, troughs, baths, etc., all in large of the greatest value to me. As a bev- wooden case, formerly the property of the late President Moore, of Columbia College. This is a erage it possesses charms beyond any-fine example of an instrument of the best make for the old wet-process methods, and valuable to any thing I know of in the form of medi-institution or amateur interested in the history of photography in the U. S. Address M. S. Daniel, cine." 236 W. 4th St., New York.

Descriptive pamphlet free.

I wish to exchange a collection of 7,000 shells, 1001 species and varieties, American and foreign, land, fluviatile and marine, for a good microscope Lorenzo G. Yates, Santa Barbara, California.

Rumford Chemical Works, Providence, R. 1. and accessories. Address, with particulars, Dr.

Beware of Substitutes and Imitations.

For exchange. I wish to exchange Lepidoptera of South Dakota and other sections, for Lepidoptera of the world. Will purchase species of North America. Correspondence solicited, particularly with collectors in the Rocky Mountains, Pacific coast and Hudson's Bay regions. P. C. Truman, Volga, Brooking county, South Dakota.

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American Bell Telephone

COMPANY.

125 MILK ST., BOSTON, MASS.

This Company owns the Letters - Patent

No. 186,787, granted to Alexander Graham
Bell, January 30th, 1877, the scope of which
has been defined by the Supreme Court of
the United States in the following terms:
"The patent itself is for the mechanical

LIGHTNING DESTROYS!

Shall it be your house or a pound of copper?

Entirely new departure in pro

QUERY.

Can any reader of Science cite a case of lightning stroke in which the dissipation of a small conductor (one-sixteenth of an

tecting buildings from lightning. inch in diameter, say,) has failed One hundred feet of the Hodges to protect between two horizonPatent Lightning Dispeller tal planes passing through its structure of an electric telephone to be used (made under patents of N. D. C. upper and lower ends respectivefirst patent rests. The third claim is for the Hodges, Editor of Science) willy? Plenty of cases have been

to produce the electrical action on which the

use in such instruments of a diaphragm, made of a plate of iron or steel, or other material capable of inductive action; the fifth, of a permanent magnet constructed as de

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scribed with a coil upon the end or ends dress, on receipt of five dollars.

nearest the plate; the sixth, of a sounding box as described; the seventh, of a speaking or hearing tube as described for conveying the sounds; and the eighth, of a permanent magnet and plate combined. The claim is not for these several things in and of them

Correspondence solicited. Agents wanted.

found which show that when the

conductor is dissipated the building is not injured to the extent explained (for many of these see volumes of Philosophical Trans

selves, but for an electric telephone in the AMERICAN LIGHTNING PROTECTION CO., actions at the time when light

construction of which these things or any of them are used."

This Company also owns Letters-Patent No. 463,569, granted to Emile Berliner, No

874 Broadway, New York City.

ning was attracting the attention of the Royal Society), but not

vember 17, 1891, for a combined Telegraph Fact and Theory Papers an exception is yet known, al

and Telephone, and controls Letters-Patent No. 474,231, granted to Thomas A. Edison,

SUMPTION. By GODFREY W. HAMBLETON, M.D.
12°. 40c.

though this query has been published far and wide elecamong

tricians.

May 3, 1892, for a Speaking Telegraph, I. THE SUPPRESSION OF CON-
which cover fundamental inventions and
embrace all forms of microphone transmit-
ters and of carbon telephones.

BUSINESS OPPORTUNITY.

There is an opening for a young man to open a New York office of the American Lightning Protection Co., operating under my patents. But little capital will be required.

N. D. C. HODGES, 874 BROADWAY, NEW YORK

INDEX

TO VOLUME XVIII OF

SCIENCE

is in preparation, and will be issued at an early date.

N. D. C. HODGES,

874 Broadway, New York, N. Y.

II. THE SOCIETY AND THE "FAD."
By APPLETON MORGAN, Esq. 12°. 20 cents.

First inserted June 19, 1891. No re

III. PROTOPLASM AND LIFE By sponse to date.

C. F. Cox. 12°. 75 cents.

IV. THE CHEROKEES IN PRE-CON. D. C. HODGES, 874 BROADWAY, N. Y.

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CAL CULTURE CHART, with illustrated directions for developing every part of the body healthfully, 50 cts. Sent for half price to those naming this paper.

WHITNEY HOME GYMNASIUM CO., Box D., Rochester, N. Y.

1893

SCIENCE

LIBRARY

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1. The relations of inflorescence to cross-fertiliza tion illustrated by the plants of Eastern Massa.

chusetts.

2. What depths of formerly overlying rocks, now removed by denudation, may be inferred from the structure of various rocks in Eastern Massachusetts?

SINGLE COPIES, TEN CENTS. $3.50 PER YEAR, IN ADVANCE.

USEFUL HAND-BOOKS.

The Ornamental Penman's Pocketbook of Alphabets, for sign-writers, engravers, stone-cutters and draftsmen, 20 cts. A System of Easy Lettering, by Howard Cromwell, 50 cts. Practical Electrics: A Universal Handybook on Every-day Electrical Matters, 185 pp., fully illustrated, 12mo, cloth, 75 cts. 79 pp., with a number of plates to scale, 12mo, cloth, Notes on Design of Small Dynamo, by G. Halliday, $1. The Phonograph and How to Construct It, by W. Gillett, 87 pp., 12 folding plates, 12mo, cloth. $2. SPON & CHAMBERLAIN, Publishers, 12 Cortlandt St., New York. Illustrated and descriptive catalogues, 10 cts.

The Batrachians and Reptiles of Indiana.

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Each memoir must be accompanied by a sealed envelope enclosing the author's name and superscribed by a motto corresponding to one borne by the manuscript, and must be handed to the Secretary on or before April 1, 1894.

Prizes will not be awarded unless the memoirs are

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NEW METHOD OF PROTECTING BUILDINGS FROM LIGHTNING. SPARE THE ROD AND SPOIL THE HOUSE! Lightning Destroys. Shall it be Your House or a Pound of Copper?

PROTECTION FROM LIGHTNING.

What is the Problem?

IN seeking a means of protection from lightning-discharges, we have in view two objects, the one the prevention of damage to buildings, and the other the prevention of injury to life. In order to destroy a building in whole or in part, it is necessary that work should be done; that is, as physicists express it, energy is required. Just before the lightning-discharge takes place, the energy capable of doing the damage which we seek to prevent exists in the column of air extending from the cloud to the earth in some form that makes it capable of appearing as what we call electricity. We will therefore call it electrical energy. What this electrical energy is, it is not necessary for us to consider in this place; but that it exists there can be no doubt, as it manifests itself in the destruction of buildings. The problem that we have to deal with, therefore, is the conversion of this energy into some other form, and the accomplishment of this in such a way as shall result in the least injury to property and life.

Why Have the Old Rods Failed?

When lightning-rods were first proposed, the science of energetics was entirely undeveloped; that is to say, in the middle of the last century scientific men had not come to recognize the fact that the different forms of energy heat, electricity, mechanical power, etc.- were convertible one into the other, and that each could produce just so much of each of the other forms, and no more. The doctrine of the conservation and correlation of energy was first clearly worked out in the early part of this century. There were, however, some facts known in regard to electricity a hundred and forty years ago; and among these were the attracting power of points for an electric spark, and the conducting power of metals. Lightning-rods were therefore introduced with the idea that the electricity existing in the lightning-discharge could be conveyed around the building which it was proposed to protect, and that the building would thus be saved.

The question as to dissipation of the energy involved was entirely ignored, naturally; and from that time to this, in spite of the best endeavors of those interested, lightning-rods constructed in accordance with Franklin's principle have not furnished satisfactory protection. The reason for this is apparent when it is considered that the electrical energy existing in the atmosphere before the discharge, or, more exactly, in the column of dielectric from the cloud to the earth, above referred to, reaches its maximum value on the surface of the conductors that chance to be within the column of dielectric; so that the greatest display of energy will be on the surface of the very lightningrods that were meant to protect, and damage results, as so often proves to be the case.

It will be understood, of course, that this display of energy on the surface of the old lightning-rods is aided by their being more or less insulated from the earth, but in any event the very existence of such a mass of metal as an old lightning-red can only tend to produce a disastrous dissipation of electrical energy upon its surface,-"to draw the lightning," as it is so commonly put.

Is there a Better Means of Protection?

Having cleared our minds, therefore, of any idea of conducting electricity, and keeping clearly in view the fact that in providing protection against lightning we must furnish some means by which the electrical energy may be harmlessly dissipated, the question arises, "Can an improved form be given to the rod so that it shall aid in this dissipation?"

A Work of 204 pages, with 3 plates of 12 figures Contains full descriptions of nearly one hundred abundant notes on their habits. The identification of the species made easy by means of analytical tables. By O. P. Hay, Ph.D. Price, in paper cover, postpaid, $1.00.

Bowen-Merrill Book Co, Indianapolis, Ind.

GERMANIA A monthly magazine for the study

of the German language and literature, is highly recommended by college professors and the press as "the best effort yet made to assist the student of German, and to interest him in his pursuit." Its BEGINNERS' CORNER furnishes every year a complete and interesting course in German grammar. $2 a year. Single copies 20 cents. P. O. Box 151, Manchester, N. H.

As the electrical energy involved manifests itself on the surface of conductors, the improved rod should be metallic; but, instead of making a large rod, suppose that we make it comparatively small in size, so that the total amount of metal running from the top of the house to some point a little below the foundations shall not exceed one pound. Suppose, again, that we introduce numerous insulating Joints in this rod. We shall then have a rod that experlence shows will be readily destroyed-will be readily dissipated when a discharge takes place; and it will be evident, that, so far as the electrical energy is consumed in doing this, there will be the less to do other damage.

The only point that remains to be proved as to the utility of such a rod is to show that the dissipation of such a conductor does not tend to injure other bodles in its immediate vicinity. On this point I can only say that I have found no case where such a conductor (for instance, a bell wire) has been dissipated, even if resting against a plastered wall, where there has been any material damage done to surrounding objects.

Of course, it is readily understood that such an explosion cannot take place in a confined space without the rupture of the walls (the wire cannot be boarded over); but in every case that I have found recorded this dissipation takes place just as gunpowder burns when spread on a board. The objects against which the conductor rests may be stalned, but they are not shattered, I would therefore make clear this distinction between the action of electrical energy when dissipated on the surface of a large conductor and when dissipated on the surface of a comparatively small or easily dissipated conductor. When dissipated on the surface of a large conductor, a conductor so strong as to resist the explosive effect,- damage results to objects around. When dissipated on the surface of a small conductor, the conductor goes, but the other objects around are saved

A Typical Case of the Action of a Small Conductor. Franklin, in a letter to Collinson read before the London Royal Society, Dec. 18, 1755, describing the partial destruction by lightning of a church-tower at Newbury, Mass, wrote, "Near the bell was fixed an iron hammer to strike the hours; and from the tall of the hammer a wire went down through a small gimlet-hole in the floor that the bell stood upon, and through a second floor in like manner; then horizontally under and near the plastered celling of that second floor, till it came near a plastered wall; then down by the side of that wall to a clock, which stood about twenty feet below the bell. The wire was not bigger than a common knitting needle. The spire was split all to piece by the lightning, and the parts flung in all directions over the square in which the church stood, so that nothing remained above the bell. The lightring passed between the hammer and the clock in the above-mentioned wire without hurting either of the floors, or having any effect upon them (except making the gimlet-holes, through which the wire passed, a little bigger), and without hurting the plastered wall, or any part of the building, so far as the aforesaid wire and the pendulum-wire of the clock extended; which latter wire was about the thickness of a goose-quill. From the end of the pendu lum, down quite to the ground, the building was exceedingly rent and damaged.... No part of the aforementioned long, small wire, between the clock and the hammer, could be found, except about two inches that hung to the tail of the hammer, and about as much that was fastened to the clock; the rest being exploded, and its particles dissipated in smoke and air, as gunpowder is by common fire, and had only left a black smutty track on the plastering, three or four inches broad, darkest in the middle, and fainter towards the edges, all along the ceiling, under which it passed, and down the wall." One hundred feet of the Hodges Patent Lightning Dispeller (made under patents of N. D. C. Hodges, Editor of Science) will be mailed, postpald, to any address, on receipt of five dollars ($5).

Correspondence solicited. Agents wanted.

AMERICAN LIGHTNING PROTECTION CO., 874 Broadway, New York City.

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Manufacturer and Builder. South to Cape Hatteras. By AUSTIN C. APGAR. This work contains a key to chanical journal, edited by DR. WILLIAM H. WAHL. Published Monthly. A handsomely illustrated meall the genera, a glossary of Molluscan terms, descriptions of all the species of shells, and over sixty Every number consists of 48 large quarto pages and illustrations. Price, Bound in Cloth. Post-cover, filled with useful information on all subjects For paid, $1. For sale by AUSTIN C. APGAR, 511 of a practical nature. Specimen copy free. sale by all newsdealers. Agents wanted everyEast State St., Trenton, N. J. where. Address

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RACES AND PEOPLES.

By DANIEL G. BRINTON, M.D.

"The book is good, thoroughly good, and will long remain the best accessible elementary ethnography in our language."-The Christian Union.

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LABORATORY MICROSCOPES.

The Reichert III (vertical, No. 8) is a favorite pattern for laboratory work, and is fitted with his best lenses.

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NEW YORK, JULY 28, 1893.

SYSTEMATIZED GRADUATE INSTRUCTION IN PSYCHOL

OGY.

BY E. W. SCRIPTURE, NEW HAVEN, CONN.

Instruction in psychology cannot be said to have been placed on a sound basis till it consists of a series of carefully graded teaching from elementary text-book instruction to the highest kind of original work. Haphazard work here is just as bad as anywhere. It is self-evident that the student of psychology should properly apportion' the amount of time spent in its various departments and in the other sciences he will have need of. The man who starts with the supposition that the way to study psychology is to go into the anatomical laboratory on the one hand and to take heavy courses in Greek philosophy on the other, is losing much valuable time. It is hereby not implied that no time is to be given to these subjects any more than that geometry and history are to be omitted from a man's education. But when a man has finished his college work and goes to the university he is supposed to have received his general culture and to be ready for his lifework.

The specialist is a man of broader knowledge than the dilettante. The difference between the two is that the latter browses at random, while the former reaches over a much wider field, but with a careful selection and coordination of the portions related to some central point. There is a maximum of energy and health which a man can employ in work; if this capital is inrested in a careless way it will bring in small returns; the man will never really gain a complete training in anything.

The problem of a specialist is to go over as much ground as possible; to do this it is necessary to pass rapidly over the less valuable portions in order to have time for the valuable ones further on. Moreover, no essentials should be overlooked, no matter how distant they apparently lie. This last requirement is probably the most important of all. There is many a psychologist to-day who is fatally weak in some one or more points; it would be easy to find those who, although making measurements, know nothing of the science of measurement, or who, using light, heat, etc., as tools in their experiments, have little idea of the laws of the forces they are handling. To remedy all these defects in the dilettante way a man would have to study a couple dozen sciences; since life is too short to learn even one with any respectable thoroughness, the only way to do is to take just what will be of the most advantage to the psychologist, always bearing in mind that an hour too much on any one point means an hour too little on some other one.

It is the first problem of the psychological laboratory or the psychological department to so arrange its courses as to satisfy these requirements. As my own experience may possibly be of use to some one I will indicate briefly the outline of a system of instruction designed to meet this want. It is to be borne in mind that I am not speaking of college work with the object of general culture, but of serious university work for one who desires to study psychology.

As the science of psychology to-day is based on measurement and experiment, the work of the student must begin with some considerations on the method of making experiments; this should be followed by careful work in the theory of measurements, treating of the probability integral, the mean variation, etc. This work resembles somewhat the corresponding work given in physical measurements, but although the mathematical princi

ples are the same, the treatment differs considerably. One of the great differences between psychological and physical measurements is that the conditions cannot yet be as accurately controlled as in physics; our mean variations are thus greater and the deductions we can draw from the results are not the same. In this respect psychological measurements on a single person somewhat resemble measurements taken once on each of a large number of persons. Partly for this reason, but mainly also for the sake of mental statistics, a study of the methods of statistics has to be made. The making of measurements brings in the study of fundamental and derived units and the construction of apparatus. The study of the various subjects of touch, sight, hearing, etc., requires a consideration of the physical processes used in stimulation. Thereafter the usual psychological subjects are, in a lecture course, to be treated in detail.

Hearing lectures will never make a psychologist; the fundamental course for all special instruction is the laboratory work. The student must be trained by repeated exercises in making the measurements explained in the lectures, including exercises on touch, temperature, hearing, sight, in the graphic method, chronometry, dynamometry, audiometry, photoptometry, colorimetry (psychological), etc. This should be followed by work in the construction of apparatus, elements of mechanical drawing, use of tools, etc. It is of great importance not to have too many men at work at the same time, at least not until psychological laboratories are much enlarged. During the past year the average attendance on this course in the Yale laboratory has been eight, an unpracticable number. Even with the enlarged equipment for the coming academic year, the number admitted to this practice course will have to be limited.

The object of university instruction, as distinguished from college training, is to develop the love of research, to train the student in research methods, to furnish him with the requisite knowledge and skill, and finally to provide him with the apparatus and other means of work for carrying out such investigations as may be best for him to undertake. The requisite knowledge of the psychological methods is gained from the laboratory course, the training in the difficulties and methods involved in research is obtained by placing the newer students as helpers to the advanced ones. The importance of this last arrangement can hardly be overestimated. It is the one in vogue at Leipzig and elsewhere.

It is a very dangerous thing for a man to take up a problem for investigation unless by previous experience with some one else he has found out that research is the hardest kind of work and has learned the thinking, the untiring patience, the courage under defeat that are called for at the various stages of work.

If we regard the research work as a means of training, it is an important matter to the student that he shall not undertake problems with rather indefinite boundaries or those where he may perchance run wild or be led into careless work. There can be no better training than that found in the investigation of a single point where the most careful measurements and manipulation are required. Once the student has learned the proper habits he will do far better work with suggestive and uncertain problems than could otherwise be hoped for.

If a student has had the proper general culture in philosophy, physics and mathematics, such a course as that outlined ought to make a thorough psychologist out of him. If he has not had the proper college training it behooves him to make it up as fast as possible. In the first place, an acquaintance with German is absolutely indispensable. Some acquaintance with the epistemological theories of the day is also necessary. A thorough scientist in psychology could not get along without knowing some

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