Popular Science Monthly/Volume 25/July 1884/Popular Miscellany


The Coming International Electrical Exhibition.—The Franklin Institute is making arrangements for the most complete representation of electrical appliances at the International Electrical Exhibition, which is to be held under its auspices in Philadelphia, from September 2d to October llth. A place is provided on its programme for every kind of apparatus and application of electricity, with the items so grouped and arranged as to make prominent the significance and value of each. Much interest is attached to the historical collection of all first and original electrical apparatus, which will form a special department, and which the committee are endeavoring to make as complete as possible. A "Memorial Library" is also to be secured, of all publications in any way pertaining to electrical science up to the date of the exhibition—to include not only books, but also papers, reprints of articles, and notes on or relating to electricity.

Deprived of the Pleasures of Taste.—A writer in the "Cornhill Magazine" says of Harriet Martineau that she had no sense of taste whatever. 'Once,' she told me with a smile, when I was expressing my pity for this deprivation of hers, 'I tasted a leg of mutton, and it was delicious. I was going out, as it happened, that day, to dine with Mr. Marshall at Coniston, and I am ashamed to say that I looked forward to the pleasures of the table with considerable eagerness; but nothing came of it, the gift was withdrawn as suddenly as it came.' The sense of smell was also denied her, as it was to "Wordsworth; in his case, too, curiously enough, it was vouchsafed to him, she told me, upon one occasion only. 'He once smelled a bean-field and thought it heaven.' It has often struck me that this deprivation of those external senses (for she lost her hearing very early) may have had considerable influence in forming Miss Martineau's mental characteristics; but if it turned her attention to studies more or less abstruse, and which are seldom pursued by those of her own sex, it certainly never 'hardened' her."

Communication with Animals.Sir: You did me the honor, some weeks ago, to insert a letter of mine, containing suggestions as to a method of studying the psychology of animals, and a short account of a beginning I had myself made in that direction.

This letter has elicited various replies and suggestions which you will, perhaps, allow me to answer, and I may also take the opportunity of stating the progress which my dog "Van" has made, although, owing greatly, no doubt, to my frequent absences from home and the little time I can devote to him, this has not been so rapid as, I doubt not, would otherwise have been the case. Perhaps I may just repeat that the essence of my idea was to have various words such as "food," "bone," "water," "out," etc., printed on pieces of card-board, and, after some preliminary training, to give the dog anything for which he asked by bringing a card. I use pieces of card-board about ten inches long and three inches high, placing a number of them on the floor, side by side, so that the dog has several cards to select from, each bearing a different word.

One correspondent has suggested that it would be better to use variously-colored cards. This might, no doubt, render the first steps rather more easy, but, on the other hand, any temporary advantage gained would be at the expense of subsequent difficulty, since the pupil would very likely begin by associating the object with the color, rather than with the letters. He would, therefore, as is too often the case with our own children, have the unnecessary labor of unlearning some of his first lessons. At the same time, the experiment would have an interest as a test of the color-sense in dogs.

Another suggestion has been that, instead of words, pictorial representations should be placed on the cards. This, however, could only be done with material objects, such as "food," "bone," "water," etc., and would not be applicable to such words as "out," "pet me," etc.; nor even as regards the former class do I see that it would present any substantial advantage.

Again, it has been suggested that "Van" is led by scent rather than by sight. He has, no doubt, an excellent nose, but in this case he is certainly guided by the eye. The cards are all handled by us, and must emit very nearly the same odor. I do not, however, rely on this, but have in use a number of cards bearing the same word. When, for instance, he has brought a card with "food" on it, we do not put down the same identical card, but another with the same word; when he has brought that, a third is put down, and so on. For a single meal, therefore, eight or ten cards will have been used, and it seems clear, therefore, that in selecting them "Van" must be guided by the letters.

When I last wrote I had satisfied myself that he had learned to regard the bringing of a card as a request, and that he could distinguish a card with the word "food" on it from a plain one; while I believed that he could distinguish between a card with "food" on it and one with "out" on it.

I have now no doubt that he can distinguish between different words. For instance, when he is hungry he will bring a "food" card time after time until he has had enough, and then he lies down quietly for a nap. Again, when I am going for a walk, and invite him to come, he gladly responds by picking up the "out" card, and running triumphantly with it before me to the front door. In the same way he knows the bone card quite well. As regards water (which I spell phonetically so as not to confuse him unnecessarily), I keep a card always on the floor in my dressing-room, and whenever he is thirsty he goes off there, without any suggestion from me, and brings the card with perfect gravity. At the same time he is fond of a game, and if he is playful or excited will occasionally run about with any card. If, through inadvertence, he brings a card for something he does not want, when the corresponding object is shown him, he seizes the card, takes it back again, and fetches the right one. No one who has seen him look along a row of cards, and select the right one, can, I think, doubt that in bringing a card he feels that he is making a request, and that he can not only perfectly distinguish between one word and another, but also associates the word and the object.

I do not for a moment say that "Van" thus shows more intelligence than has been recorded in the case of other dogs—that is not my point—but it does seem to me that this method of instruction opens out a means by which dogs and other animals may be enabled to communicate with us more satisfactorily than hitherto. I am still continuing my observations, and am now considering the best mode of testing him in very simple arithmetic, but I wish I could induce others to co-operate, for I feel satisfied that the system would well repay more time and attention than I am myself able to give. I am, sir, etc., John Lubbock.

High Elms, Hayes, Kent.

London Spectator.

Gas-Poisoning.—According to statements of Professor Pettenkofer at the recent Hygienic Congress in Berlin, the poisonous property of coal-gas depends upon its containing carbonic oxide in the proportion of about ten per cent, while the other constituents, although irrespirable, do not act as direct poisons. The danger in breathing the gas depends not so much on the duration of the exposure to a mixture of air and carbonic oxide as upon the amount of the latter contained in the air. Air containing only a proportion of five parts of carbonic oxide in 10,000 can be breathed for hours and even days by men and animals without any injury to health; while a proportion of seven or eight in 10,000 causes appreciable discomfort; of twenty in 10,000, difficulty of breathing, weakness, and uncertainty in gait; a proportion of twice that ratio leads to stupefaction, and higher proportions to extreme and fatal effects referable to the nervous system. Illness attributable directly to the entrance of gas into the house from the mains has been found to increase in the winter months, largely, probably because of the closing of the windows and the artificial heating of the rooms by which the gas is attracted into them. Dr. Pettenkofer has cited several striking instances of severe affection and even death that occurred in dwelling-houses in consequence of leakage from street-mains. At Roveredo, two sisters who slept in a basement contracted severe headaches during three successive nights. On the fourth night, which was a very cold one, the mother slept with them. None of the three appeared on the following morning, and on investigation the two sisters were found dead, and the mother so nearly so that she only survived a few days. The escaping gas, under the roadway, was thirty-five feet distant from the room. At Cologne, three persons in one family were killed in a single night in 1871, by a leak ninety-eight feet away. The superintendent of a prison in Breslau died and his sons were afterward found unconscious, in the same room, in 1879, from a leak thirty-five and a half feet away. Another instance has been recorded in Breslau, where the distance of the leak was one hundred and fifteen feet. At Cologne the gas passed through a sewer-channel and through the floor, while in the other cases it traversed layers of earth. The variation in the degree of cold between one night and another, causing corresponding differences in the force by which the gas is attracted to the rooms, would, in Dr. Pettenkofer's opinion, sufficiently account for the difference in the gravity of the effects produced on these occasions. Gas filtered through the soil from the mains may be quite odorless, at least until it has collected in large amount; and herein lies the danger to dwellers in the basement. On the earliest occurrence of such symptoms as headache, the windows should be thrown open; and if, on closing them again, the symptoms reappear, it may be suspected that gas is escaping into the house.

Dr. Crothers's Studies of Inebriety.—Dr. T. D. Crothers, of Hartford, Connecticut, read before the London Branch of the British Medical Temperance Society an historical paper on the study of inebriety in America. A fact of psychological interest pertaining to the subject is, that inebriety in this country moves in waves and currents, with a decided epidemic and endemic influence. This can be traced in the rapid increase of drunkenness in towns and cities, till after a time a reaction sets in, and a marked decline follows. "These waves of inebriate storms that sweep over large circles of country are always followed by intense revivals of temperance interest, and are fields of the most fascinating psychological inquiry yet to be studied." An increase of inebriety among our women is asserted as apparent in the great demand for narcotics, the sale of beer and wine by grocers, and the divisions of saloons by general and family entrances, with separate rooms for each. The vice is considered a pronounced form of brain and nerve degeneration coming from well-marked physical conditions, largely controlled by social and psychical states peculiar to the country. The symptomatology of the disease "more nearly resembles that of insanity and general paralysis; its course is in waves and currents; its progress is shorter; and among women the use of narcotics is more prevalent than that of other forms of alcohol." In estimating the value of remedies, Dr. Crothers believes that all efforts by moral means have failed, and are of value almost exclusively as agitations that will call attention to the evil. Legal means, by cocrcion and punishment, are likewise inefficacious, although there may be a value in prohibition, to be determined by the experience of the future. In his own view, inebriety being regarded as a disease, like insanity, should be, like insanity, treated as a disease; and the cure should be sought in the enlightened treatment of the inebriate asylums.

How to expose Thermometers.—Dr. H. A. Hazen discusses, in the "American Journal of Science," the conditions of thermometer exposure best adapted to secure uniform accuracy in the indications of temperature. One of the first conditions to be regarded is that of securing a good height above the ground, on which considerable diversity of opinion prevails. Much depends upon the immediate conditions of the locality. When this point is decided upon, a uniform and satisfactory shelter or screen should be provided for the instrument. The height and the screen should be so adjusted that the thermometer shall be free from the influence of ground-fog and that access of the air to it should be perfect. The shelter should shield from all reflected heat, from all direct radiation, from the sun by day, and from the earth to the sky by night, and from all radiation from surrounding objects, as well as from moisture. Many different forms of shelter have been contrived in different countries. In experimenting upon the merits of these devices, a standard of comparison is found in the swung thermometer, or, as the French call it, the thermométre fronde which is a common thermometer attached to a string or wire, and rapidly swung through a circumference whose radius is the length of the string. The theory of this arrangement is that, as the instrument is rapidly brought in contact with a large mass of air, it must give the temperature of the same unless the results are vitiated by other causes. From a number of experiments described by Mr. Hazen, the following conclusions as to the best dispositions of shelters are advanced: When exposed to direct sun-heat, they should be at least thirty-six inches long; with proper precautions the thermometer "fronde," both dry and wet, will give the most correct air-temperature and relative humidity; a single louvre shelter is sufficient. The interposition of a second louvre prevents the free access of air, and if ventilation is used it must affect the air which is propelled to the thermometer. For obtaining even approximate relative humidity in calm weather, single-louvred shelters are necessary, and for the best result an induced air-current is essential, especially in the winter in northern countries. Where a window shelter is used, there should be a free air-space of from six to twelve inches between the shelter on the north side of the building and the wall. The simplest form of screen would be four pieces of board ten or twelve inches square, nailed together box-fashion, leaving the bottom and the side toward the window open; the thermometers, dry and wet, should be placed five inches apart near the center of this screen, with their bulbs projecting below the plane of the lower edge. Shade may be given, at such times as the sun is shining on the north side of the house, by the adjustment of the window-blinds.

Numismatics in the United States.—From a paper read by Mr. W. Lee before the Philosophical Society of Washington, we learn that an extended interest in numismatics began to show itself in this country in 1858, at which time there were probably not as many as a hundred coin-collectors in the United States. The interest has grown rapidly, until now there must be on the books of the United States Mint the names of at least one thousand collectors who receive yearly the issue of the mint, with special proof-polish. In New York, alone, during the year 1882, thirty-nine collections were sold at public auction, and brought, in all, $68,441.36. Several of our large cities have numismatic societies, some of which are designated as numismatic and archaeological societies; and a number of periodicals devoted simply to the interest of numismatics obtain a satisfactory circulation.

Seasonal Variations of Rheumatism.—The records of rheumatic cases in the London Hospital fail to show any clear relation between the prevalence of the disease and particular climatic conditions. Dr. Henry S. Gabbett has compared the graphic curves representing the numbers of cases observed for nine years, and remarks a general similarity between them. In nearly every case a wave is noticed beginning to rise at the opening of summer, and reaching its highest elevation in July or August; then comes a temporary check or fall, followed by a rapid ascent till the summit is reached, at the end of autumn, when a steady fall occurs through the months of December, January, and February, till a low level is reached, which continues nearly even till about the beginning of the next summer elevation. The curves for different years do not appear to be affected by variations in the character of the seasons from which it is possible to make any deduction respecting the influence of variations of temperature or of conditions of moisture. Accepting Messrs. Buchan and Mitchell's division of the London year into six periods, each having a climate peculiar to itself, "we find that rheumatism was most prevalent in the annual damp and cold period; next in the damp and warm period; cases were about equally frequent in the two periods characterized respectively by heat and cold; below these comes the dry and warm period; and lowest of all, as regards the frequency of the disease, the period described as dry and cold.... It does not, however, necessarily follow that there is any etiological connection between the above facts; the periodical prevalence of the disease may possibly be independent of conditions of climate." Dr. Gabbett draws the conclusions, with a little more confidence, that the disease is neither most prevalent in the coldest months of the year, nor least prevalent in the warmest; that it does not occur with greatest frequency in those months in which the daily variations of temperature are greatest; that, although there is a certain correspondence between the rainy periods and the times when rheumatism is common, it is not close enough to point to any necessary connection. But cases of the disease are very numerous at that period of the year during which there is usually a coexistence of low temperature and heavy rainfall—viz., the end of autumn.

Shall we put Spectacles on Children?—In a paper with this title Professor Julian J. Chisholm, M. D., of the University of Maryland, makes a plea for providing children with the means of counteracting their congenital or acquired defects of vision. According to the traditions, the need of spectacles is an indication of old age, and so the world interprets it. A better knowledge, however, is diffusing itself among the medical profession, and from them to the public. While advancing years may be a factor, it is only one of many causes inducing defective vision. The action of the perfect eye conforms to the law of optics that, unless a lens focuses accurately on the recipient surface, the image made must be more or less imperfect. In front of the lens there is a broad, circular ligament of the eye, which presses against it, and, when objects at a short distance are to be looked at, by the action of a muscle (the ciliary), the compressing ligament is relaxed, so that the lens, its natural elasticity responding at once to the relief, becomes more convex, and is, therefore, in condition to focus more powerfully light coming from near objects. What is called accommodation, or ability to change the focus, is, then, a muscular act. When the accommodating muscles are temporarily enfeebled by diseased conditions of the system at large, they do not lift off sufficiently the flattening band, or they are too weak to keep up the continued action for the relief of lens pressure; hence we often find children recently recovered from an attack of measles, scarlet fever, diphtheria, whooping-cough, or from any one of the depressing diseases of childhood, unable to study as they did before the attack. A weak magnifying spectacle, by helping the muscles to do their work, will enable such children to continue their studies till tonics daily administered restore the needful strength to the enfeebled muscles. The foregoing statements are based upon perfect eyes. Unfortunately, the eyeball, with the many other features, has not always the perfection of symmetry. Near-sighted long eyes and over-sighted flat eyes are the common deviations from the standard shape. In the near-sighted eye, called myopic, the eye is so long from front to back that the lens is too far from the retina. The result is, that rays of light from a distant object come to a focus, and have begun to diverge when they reach the retina, so that the image formed is blurred. The second deviation in the form of the eye is called hyperopia. This is a flat eye, a very common form in children. It is a congenital defect, in which the crystalline lens is located so near the retina that light, passing into the eye, is stopped by the retina before it comes to a focus. This must also produce an ill-defined picture. Unfortunately, faulty eyes, which give out under use, do not appear differently from perfectly shaped ones. The flattening, or the elongation, is not in the exposed cornea. It is usually at the expense of the inner half of the eyeball, hid away in the socket. If children, either by inheritance or acquisition, have misshaped eyes, so that they can not see objects clearly through the usual range of distances, what can be the propriety of allowing them to go through life as if in a constant fog, when a properly selected glass clears up the mist, and enables them to see as others do?

Fresh-Water Pearls.—The cultivation of the pearls of fresh-water mussels has become an industry of considerable importance in Saxony and other parts of Germany. The pearls are generally inferior to those of the genuine pearl-oysters, but occasionally a gem of real excellence is produced. Some very fine settings of such were exhibited at the Exposition in Berlin. The Venetians carried on this branch of trade to a considerable extent during the middle ages, and controlled it till 1621, when the Elector of Saxony also undertook it, at the suggestion of Moritz Schmirler, a draper of Oelsnitz, and appointed Schmirler "first pearl-fisher." Schmirler was succeeded on his death by his son, and the business has continued in the family to the present day, under the superintendcncy of the forestry department, which has also to do with the waters of the region. The pearl-hunting is carried on in the spring, as soon as the water is warm enough to wade in for hours continuously. The mussels are examined by means of an instrument, by which the shells can be opened enough to see what is within them without hurting the mollusks. If they contain well-developed pearls, they are sacrificed; if not, they are returned to the beds. The same beds are not usually gone over again for several years. Experiments made in the Elster, in the artificial production of pearls, have not met with much success. A wound in the mouth of the mollusk will lead to the deposition of the calcareous matter, but it is uncertain whether it will be of common shell-matter or of pearl—and upon this all the value of the operation depends. In the Dutch East Indies, the formation of pearls in the pearl-oyster is sometimes provoked by inserting a grain of sand within the shell. A considerable business is done at Adorf in the manufacture of articles of fancy from the nacre of mussels.

Geological Survey of Palestine.—Professor Hull has just made a successful geological survey of Palestine, preparatory to the construction of a geological map of the country. He has traced the ancient margin of the Gulfs of Suez and Akabah to a height of two hundred feet above their present level, so as to show that the country has been submerged to that extent and has been gradually rising; and he believes that at the time of the Exodus a continuous connection existed between the Red Sea and the Mediterranean. The Dead Sea appears to have formerly stood at a height of fourteen hundred feet above its present level, or about one hundred and fifty feet above the level of the Mediterranean. Evidences of a chain of ancient lakes have been found in the Sinaitic district, and of another chain in the center of the Wady Arabah, not far from the water-shed. The great line of fracture of the Wady Arabah and the Jordan Valley has been traced to a distance of more than one hundred miles, and the materials for working out a complete theory of this remarkable depression are now available. The terraces of the Jordan have been examined. The relation of these terraces to the surrounding hills and valleys shows that they had already been formed before the water reached their former level; sections have been carried east and west across the Akabah and the Jordan Valley, and two traverses of Palestine have been made from the Mediterranean to the Jordan.

Change as a Recreative Agent.—Sir James Paget spoke, in a recent address, at the Workingmen's College, London, on the value of change as a mental restorative, and found it to consist principally in directing the patient to some form of "work" for which he has inherited a special capacity. The effect is produced through the awakening and gratification of some dormant love or propensity which lies deep down in the individual nature and has been inherited. It thus appears that the special pleasures of individual lives are ancestral, or are "survivals in us of instincts that belonged to our distant ancestors, who of necessity had to kill, to fish, to hunt, to clear the forests, and make the roads." The mere recommendation of "change" vaguely is idle; but recreative change, judiciously recommended and specifically applied, is one of the most powerful agents we possess for the treatment of disease, or of derangements and disturbances of the mental temperament and the mind.