Popular Science Monthly/Volume 59/May 1901/The Progress of Science
There appears to be no abatement in expeditions for polar discovery and adventure. Lieutenant Peary remains in the far north, seeking to reach a point nearer to the Pole than did Dr. Nansen and the Duke of Abruzzi's party, while with the same object in view Mr. Baldwin is preparing an expedition, liberally equipped by Mr. Ziegler, of New York City, and Captain Bernier is making efforts to secure a similar outfit in Canada. These expeditions are perhaps not primarily for scientific research, though they should add to knowledge in many directions. The expeditions being fitted out with the assistance of the German and British Governments for antarctic exploration are, however, strictly scientific in character. Exploration in the north has never relaxed, but since Sir James Ross returned, in 1843, efforts to explore the south polar region have been sporadic and comparatively unimportant, until the recent expeditions under Captain de Gerlache and Mr. Borchgrevink. The scientific results of these expeditions have not yet been published, though descriptive volumes by Mr. Borchgrevink and Dr. Cook have recently been issued, and the latter has contributed to the present number of this Journal an interesting account of the unknown southern aurora. The 'Belgica,' from which Dr. Cook made his observations, was not, however, altogether fortunate in its course, and possibly the dramatic interest of the first antarctic night is greater than the scientific interest of the results. Mr. Borchgrevink followed pretty closely in the track of Sir James Ross, and his own book contributes little or nothing to scientific knowledge. He reached by a day's expedition a point furthest to the south, but it is not even obvious how he determined this, when he estimates the semi-diameter of the sun as 16° 17' 1". However valuable the scientific results of the voyages of the 'Belgica' and of the 'Southern Cross' may prove when published, there is certainly room for the great expeditions now being made ready in England and in Germany.
The 'Discovery,' which will carry the British Antarctic Expedition, was launched on March 21 from the yard of the Dundee Shipbuilders' Company. No fewer than six ships with this name have been engaged in British exploration, and the present vessel is somewhat similar to its namesake, which took part in Sir George Nares's expedition in 1875. But it, of course, contains all modern improvements, and is of unusual strength. The oak ribs are placed as close together as possible. These are covered on the outside with oak and greenheart and on the inside with asbestos, while the bow is cased with steel plates. The tonnage is 1,750, the length at the water line 172 feet, and the extreme breadth 33 feet. The engines are of 450 horse power, giving a speed of about eight knots an hour, but to save coal they will be sparingly used, the vessel being rigged as a bark with three masts. Great care has been taken with the interior fittings to secure the greatest possible efficiency of scientific work, with due regard to the comfort of the company. The vessel is under the command of Capt. Robert Scott, and Prof. J. W. Gregory, who has recently gone from the British Museum to Melbourne University, is in charge of the scientific work. The expedition will begin its work at Victoria Land, facing New Zealand, where Ross and, recently, Mr. Borchgrevink, have explored furthest to the south. The German expedition, under Dr. von Drygalski, is also making active preparation, and its vessel—which has been named 'Gauss,' in honor of the great mathematician—was launched on April 1. Expeditions to cooperate with those from England and Germany are also planned in Scotland and Sweden. It seems unfortunate that the United States, which sixty years ago, at the time of the great antarctic expeditions by Ross, d'Urville and Balleny, sent Wilkes with five vessels, should not be represented in the present movement to make a thorough exploration of the antarctic regions.
While Great Britain is sending out its antarctic expedition at a cost of $500,000, a less pretentious, but perhaps equally interesting expedition is being planned. In view of the enormous importance attached to the recent discoveries of the relation of mosquitoes to malaria, and perhaps to yellow fever, Dr. Patrick Manson has urged the sending of a party to the islands of the Pacific, and, in the first instance, to Samoa, to study the life history of the mosquito and the conditions on which its existence and development depend. In certain of the islands of the Pacific, elephantiasis, a disease also due to the mosquito, is so prevalent that it occurs in half or more of the population, while in other islands it is entirely absent. It is hoped that the study of the distribution of mosquitoes, and, perhaps, experiments on their introduction, may show what is antagonistic to their development, thus making it possible to find a means of destroying them when they are present. Towards this plan the sum of $2,500 has been subscribed anonymously, and it is hoped that the British Government will assist in providing the $10,000 necessary to carry it into effect. It seems evident that the Department of Agriculture should at once undertake the study of the distribution of the malaria-bearing mosquitoes in the United States. The annual money loss to the country through the prevalence of malaria may be as little as $10,000,000 or as much as $100,000,000, but it is in any case so enormous that a thorough investigation, at whatever cost, would be in the direction of the strictest economy. There are, for example, no Anopheles on Manhattan Island, but within a mile of it they are abundant and malaria is prevalent. It may be supposed that the value of real estate, at the seashore and mountain resorts, for example, will be doubled or halved, according as Anopheles are absent or present.
The plague has now been so long prevalent in India that the newspapers no longer regard it as necessary to report on it, and probably very few think of its ravages, yet the deaths in Bengal alone during the last week, of which reports are at hand, were 4,000, and the recent census of India shows that the population of Bombay is 50,000 less than before the epidemic. The occurrence of the plague at Cape Town has, however, attracted notice, in view of the possibility of its spreading in the British Army, and attention has recently been called to the existence of the disease in San Francisco. It has for a long time been known in medical circles that there have been cases of plague in the Chinese quarters, but the State authorities have denied their existence and have attempted to suppress any information in regard to the epidemic. It appears that Secretary Gage appointed some time since, in spite of the protest of the Governor of California, a commission to investigate the matter. This commission, consisting of Prof. Simon Flexner, of the University of Pennsylvania; Prof. F. G. Novy, of the University of Michigan, and Prof. L. F. Barker, of the University of Chicago, has made a thorough investigation and has presented a report, from which it appears that thirty-two fatal cases have occurred in San Francisco during the past year; and this probably is incomplete, as six deaths were discovered by the commission referred to above in the course of a single week, and no cases have been reported that were not fatal. The State has now been aroused, and has appropriated $100,000 for the Board of Health to use in the suppression of the epidemic. One branch of the Legislature passed a most extraordinary bill, making it a felony to publish, by writing or printing, that Asiatic cholera or bubonic plague exists within the State, unless the fact has been determined by the State Board of Health and entered upon its minutes, but this measure appears now to have been dropped. The San Francisco papers have apparently been only too ready to suppress information in regard to the plague in that city. It appears that the epidemic is slight, but it will naturally be exaggerated by attempts to deny its existence for commercial reasons.
Within the past six months the attention of the English public has been attracted in an unwonted degree to the question of the purity of alcoholic liquors. There occurred last fall, in Lancashire, and especially in Manchester and its vicinity, large numbers of cases of arsenical poisoning, which were finally traced to the consumption of a particular brand of beer. Further investigation revealed the fact that the manufacturers of this beer used in brewing, glucose of a certain make, and that the manufacturers of this glucose had recently begun to use in its preparation a sulfuric acid which was made from pyrites containing, as is almost invariably the case, arsenic. Prior to this time it appears that the sulfuric acid used had been that made from sulfur. It was a long chain of evidence, but was complete, for arsenic was found in the beer, in the glucose, in the acid and in the pyrites, and the amount found in the beer corresponded to that in the ingredients used in its manufacture. The quantity was amply sufficient to occasion all the symptoms of poisoning which were noticed. Several points of interest have been brought out in the voluminous discussions which have followed this incident, or tragedy, as it would be better to call it. In the first place, attention has been called to the difficulty of detecting arsenic in beer and similar liquids by methods which had been commonly used. In this way several analysts were led to pronounce beer to be free from arsenic, which was afterwards shown by other methods to contain notable quantities of the poison. It now appears that the test most to be relied on in such cases is that of Reinsch, which consists essentially in boiling the beer, strongly acidified with pure hydrochloric acid, with clean copper foil, and then subliming the black deposit obtained on the copper, if arsenic is present, in a glass tube. The presence of a sublimate of bright octahedral crystals of arsenious oxid is certain evidence of arsenic in the beer. Difficulties in carrying out the ordinary tests for arsenic with many beers which were examined in large numbers when the public had been aroused to the danger of contaminated beer, led to the discovery of substances added to the beer, which had no legitimate place in brewing, and which bid fair to occasion a much closer supervision of this industry in the future. Attention has been called also to other industries where sulfuric acid is used, and where arsenic which may be present would be carried over into products destined for general consumption. This is especially true in the case of many substances used in pharmacy. It has also been shown that inasmuch as sulfur is always accompanied by small quantities of the rare element selenium, it is not impossible that its compounds, which are very poisonous, may often be present in sufficient quantity to exert a deleterious influence.
This subject has been given a somewhat different turn by the work of Sir Lauder Brunton and Dr. Tunnicliffe upon the injurious constituents of distilled liquors. It is now nearly a score of years since the remarkable experiments of Dujardin-Beaumetz on the toxic action of the different alcohols. He found that the toxic action of pure ethyl alcohol (common alcohol) was in a certain sense nil, that is to say, hogs which were kept in a condition of intoxication most of the time for nearly three years, on being allowed to sober up, appeared to be in perfect health, and presented after slaughtering no visible lesions of any organ. This was the case when absolutely pure liquor was used, but when ordinary spirits were fed to hogs they quickly succumbed, showing symptoms and lesions, especially of the liver, similar to those only too familiar in the case of human inebriates. The conclusion, drawn by Dujardin-Beaumetz from a long series of experiments, was that the toxic quality of alcoholic liquors is due chiefly to the presence of higher alcohols, especially amyl alcohol, the principal ingredient of fusel oil, though methyl alcohol and aldehyde may play a subordinate part. Under any circumstances no distilled liquor is safe to use till it has been 'aged' for several years in the wood. Brunton's researches, on the other hand, seem to show that the presence of fusel oil, in such quantities as it usually occurs in potable liquors, is not a menace to public health, but that the greatest danger is from the presence of furfural and other similar aldehydes, which are derived from the husk of the grain under the influence of heat and acids. Furfural is present to a greater or less extent in all whiskies, but is especially abundant in those made by modern processes, where it is sought to obtain as much liquor as possible per bushel of grain. According to this, the superiority of the liquors of 'ye olden time' was due not so much to the fact that they were better 'aged,' but because they originally contained less of the furfural, having been made more carefully. Brunton's physiological experiments were exceedingly interesting, especially in comparing the after effects of intoxication from ordinary spirits with those of spirits from which the furfural had been removed. In the latter case as soon as the animal was sober it appeared to be in a perfectly normal condition, and showed none of the after effects, which in the former case lasted for a considerable time. It is also worthy of note that those substances popularly used as 'bracers' after intoxication generally contain ammonia or some allied compound, which, from a chemical standpoint, is capable of combining with the furfural and neutralizing its effects.
Since the comparatively recent condensation of hydrogen to a liquid, much study has been devoted to its physical properties, and especially to the determination of its boiling-point, since this is not far above the absolute zero. The difficulty regarding the former determinations, which gave the boiling point as - 238.4° C., is that being obtained by means of a platinum resistance thermometer, they depended upon extrapolation, which might prove faulty at such low temperatures, as has now indeed been shown to be the case. More recently Dewar has made use of a constant-volume gas thermometer, employing for the gas hydrogen from different sources, and also helium, contaminated with only slight traces of neon. The results obtained show that the boiling-point of hydrogen is - 252.5°, or 20° above the absolute zero. Investigations as to the temperature of solid hydrogen are now being carried out, and show a still closer approach to the absolute zero. For some years the researches of Gautier in Paris have indicated that hydrogen is a normal constituent of the atmosphere, and the question may now be considered as settled. Not only has Dewar condensed hydrogen directly from the atmosphere, but Gautier has made quantitative determinations of the amount in different localities. In the air of Paris hydrogen does not seem to be an invariable constituent, though methane (marsh gas) is always present and traces of carbon monoxid, while the unsaturated hydrocarbons are generally absent. In forest air traces of hydrogen were present, and about half as much methane as in the air of Paris. At a mountain station in the Pyrenees at an elevation of 2,785 meters only two volumes of methane per 100,000 were found, but seventeen volumes of hydrogen. At a sea station, 40 kilometers from the coast of Brittany, only traces of methane were found, but nearly two volumes of hydrogen in 10,000, an amount two-thirds as great as that of carbon dioxid. The source and fate of atmospheric hydrogen is a problem which now awaits solution. Liveing and Dewar seem of the opinion that there is a continual accession of hydrogen to the atmosphere from interplanetary space, and Stoney holds that the earth's gravitational attraction is insufficient to retain hydrogen in the atmosphere. Experiments of Gautier show that when certain crystalline rocks are heated with water a considerable quantity of hydrogen is evolved, which might cause a constant accession of the gas to the atmosphere. The problem must be considered for the present unsolved.
Professor Nipher, of Washington University, St. Louis, has discovered that the most sensitive photographic plates may be manipulated in open daylight, and perfect pictures may be developed upon them in sunlight instead of in the dark room. The pictures are separately wrapped in black paper in the dark room, and boxed. They may then be separately unwrapped, in the open fields if necessary, and placed in the plate holders. The camera exposure must be very much greater than in the dark room methods. After the exposure, the plate is taken out into the light and placed in the developing solution. Even if direct sunlight falls upon the plate for a moment during these changes, fine pictures may be developed. There is, however, no advantage in unnecessarily exposing the plate. The developing bath may always be in shadow, but beautiful pictures have been developed in direct sunlight. The pictures produced in this way are positives, while those produced in the dark room by ordinary methods are negatives. The positive is the picture ordinarily obtained by printing off from the negative. The shadows show light on the negative and dark on the positive. The positives produced in this way are greatly superior to those produced in the dark room on over-exposed plates, and the exposure time is very much less, but may be very great. Such pictures of a crowded street show the street with perfect clearness, every moving thing being eliminated. In one exposure lasting for several hours, a team which had stood in one position for half an hour showed no trace upon the plate when developed.
Every one who has had experience in photography has lost valuable plates by over-exposure. But Professor Nipher shows that all exposures may be successfully developed. Exposures ranging from a snapshot to an overexposure of about 2.000 may be developed in the dark room as negatives. The fogging in over-exposed plates is an approach to a zero condition, where the plate is blank. For such exposures bromide is freely used, and a few drops of saturated hypo are added. In ordinary dark room work hypo is carefully avoided. But as the zero condition is approached, it is very useful in keeping the plate clear. As soon as the exposure is so great that the plate cannot be controlled in the dark room, it may be developed in the light. Plates a million times over-exposed can be thus developed. The amount of illumination of the plate while being developed depends upon the amount of exposure in the camera. Instead of using the camera, the plate can be exposed in a printing frame, where it takes the place of the sensitive paper. An exposure of two or three minutes, just out of direct sunlight at a south window, may be developed in the same light. The best results are obtained with a hydrochinone developer. Some photographic plates have given poor results in daylight, and Professor Nipher recommends Cramer's 'crown' plate.
The new star in Perseus, which has now waned in the sky, and in the memory of most people, is still an object of discussion among astronomers. Our readers will remember Professor Newcomb's recent article on variable stars and the difficulties in the way of accounting for their periodicity. In the extreme case of new stars the difficulty is greatest. The theories of an outburst from the molten interior and of collision might account for the appearance of the star, but do not explain its rapid waning, nor are they in accord with spectroscopic determinations. Professor Seeliger's theory that a dark star passes through a swarm of meteors is the most satisfactory form of hypotheses, but leaves room for the ingenious suggestion, recently made by the great astronomer, M. Janssen, before the Paris Academy of Sciences. He points out that the apparent absence of oxygen from the sun may be due to its existence in some dissociated condition that the spectroscope would not reveal. This condition may be owing to a very high temperature, and when this becomes low enough to allow oxygen to assume its common form, and so to unite with hydrogen, there would ensue, as a result of the combustion, a great increase in heat and light, which would account for the brilliancy of a new star. The rapid decrease in brilliancy which follows would be accounted for by the formation of an atmosphere of vapor, which would serve as a gradually increasing obstacle to radiation from the star. A corollary of M. Janssen's supposition is that our own sun may at any time reach this transition point for oxygen and blaze out into a fury of heat and light that would scorch all life off the face of the earth. It is, however, a pleasant feature of solar catastrophes that astronomical time is measured by millions of years.
One of the most interesting total eclipses of the sun, which the present century furnishes, will occur on May 18, 1001. The maximum duration of totality, which will be about six and a half minutes, is rarely surpassed. This will give exceptional opportunity, provided the sky is clear, for work of any kind, photographic or visual. The region of totality is, however, inconveniently remote, and the weather conditions, which usually prevail at the stations which will be occupied, are not of the best. The shadow begins off the east coast of Africa, a short distance to the southwest of Madagascar, sweeps northeasterly over the Indian Ocean, and crosses Central Sumatra, Southern Borneo and New Guinea, and a few smaller islands. To visit the track of the eclipse from New York, therefore, one must journey half way around the earth, and it matters little, so far as distance is concerned, whether one starts east or west. In spite of the distance, observations will be undertaken by a number of American and European astronomers. In this country, the Yerkes, Lick, Columbia, Amherst and Naval Observatories and the Massachusetts Institute of Technology will be represented by skilled observers. Under the auspices of the Royal and Royal Astronomical Societies, English observers will be stationed at Mauritius, and Padang, on the west coast of Sumatra. At Padang the eclipsed sun will be only 21° from the zenith, and the duration of totality about six and a half minutes. At Mauritius, the chances for a clear sky are much greater than at any other station, but the duration of the total phase is only three and a half minutes. On this account, nearly all the American and European observers are planning to visit Sumatra. The observations may have an added value from the fact that the eclipse occurs near the time of minimum sun-spot activity.
The chief part of the work in this, as in other recent eclipses, will doubtless be photographic. Owing to the enormous advantages which photographic methods of research give, they should undoubtedly be extensively employed, but it may be hoped that visual observations by skilled observers will not be neglected. There is a tendency in certain directions to regard solar eclipses as of less importance than formerly. This may be due, in part, to the fact that investigations, which in the past could only be carried on at times of total eclipse, can now be studied throughout the year, and, in part, to the very large number of observations which have already been made. Eclipse expeditions, also are very expensive, and often end in total failure, owing to clouds. Photography has multiplied the results many times in recent years, but for the solution of many problems in solar physics, as complete records as possible for a long time are necessary. In spectroscopic lines it seems hardly possible to obtain too much material for some time to come. Perhaps more of mystery and interest attaches to the corona than to any other feature, and the present eclipse gives an excellent opportunity for several lines of investigation, in addition to photographs showing its structure and extent. An attempt will again be made to investigate the rotations of the corona, by photographs of its spectrum, which must be sufficiently good to show the slight displacement of the lines caused by the motion of rotation. It is to be hoped, also, that further bolometric observations will be made on the heat radiations of the corona, as well as a study of the polarization of the coronal light. Aside from the sun itself, the existence or non-existence of an intra-mercurial planet has not been clearly demonstrated, since investigations in that line up to the present time have not been conclusive. Certainly no amount of time and labor can be regarded too great, which may be necessary to give us as complete a mastery as possible of the problems which relate to our great parent, the sun.
Yale and Princeton, the two most conservative of our larger universities, have recently taken action that will bring their college courses more into harmony with those of other leading institutions, by giving greater opportunity to elect scientific in the place of classical studies. At Yale, Greek and Latin are still required through the freshman year, but later these studies are elective. In the sophomore year five or six courses must be elected from twelve that are offered, making it possible for a student to specialize in science. In the junior and senior years, the chief work of the student may also lie in the sciences, unhampered by restrictions other than that he must take two courses in languages and literature and two courses in philosophy, history and social science. Courses can also be elected, as at Columbia and Pennsylvania, which count as part of the medical course. At Princeton, President Patton has made somewhat similar proposals looking towards offering courses in physiology and human anatomy, so that students may begin their medical education in the senior year. He, at the same time, suggested adding to the electives in the sophomore year. At present Princeton University requires Latin, Greek and the Bible through the freshman and sophomore years, while about one-third of the student's time is occupied with required studies in the junior year.
Cornell now admits students to its B. A. course without Latin, and Harvard requires no Latin at the University, but still maintains an entrance examination. Columbia requires Latin in the freshman year, but has recently made it possible for a student to enter without Latin, though he cannot graduate until he has studied this language. The great universities of the Middle and Western States have in most cases established three degrees—A. B. for those who pass entrance examinations in Latin and Greek and study these languages to a greater or less degree in their college course; B. Ph. for those who do not study Greek, and B. S. for those who study neither Latin nor Greek. It has resulted that only a small proportion of students has taken the A. B. degree, yet the other degrees referred to have no definite and well established meaning. The bachelor of science degree, for example, does not mean that a student has had a scientific education, but simply that he has not studied Latin and Greek. Under these circumstances it appears that the Universities of Michigan and Minnesota have during the past month taken a forward step in abolishing all college degrees except the A. B., giving this for all courses of liberal studies. It is obvious that the A. B. no longer means a classical education when both in England and the United States its only condition is 'small Latin' in the preparatory school. Scientific students might like to see a degree established that definitely signifies a scientific education—as the B. So. of the University of London. The authorities of Columbia University recently considered the desirability of offering such a degree, but it was thought impossible to give the B. S. a definite signification.
Dr. George Davidson, professor of geography in the University of California, has been elected a correspondent of the Paris Academy of Sciences.—St. Andrews University has conferred its LL. D. on Mr. Alexander Agassiz, of Harvard University, and Aberdeen University has conferred the same honor on Professor Rudolf Virchow, of Berlin.—]Mr. J. J. H. Teall, F. R. S., has been appointed director-general of the Geological Survey of Great Britain and Ireland, in succession to Sir Archibald Geikie. who retired on February 28. Sir Archibald has been in the service of the Survey for forty-six years and has reached the age limit.—Prof. S. M. Babcock, of the University of Wisconsin, inventor of the Babcock milk test, was, on March 27, presented with a medal, voted him by the State for giving his invention free to the world. Exercises were held in the Assembly Chamber of the Capitol in the presence of both Houses of the Legislature, the university faculty and regents and many prominent citizens of the State. Governor Lafollete presided, and addresses were made by him, by ex-Governor W. D. Hoard and others.—A committee has been formed to erect at Heidelberg a monument in memory of three of its great scientific men, Bunsen, Kirchoff and von Helmholtz.—A memorial marble bust of Robert Brown, the eminent botanist, formerly a student at Aberdeen, presented to the university by Miss Hope Paton. has been unveiled in the picture gallery of Marischal College.—Three expert geologists from the United States Geological Survey (Dr. C. Willard Hayes, Mr. T. Wayland Vaughan and Mr. A. C. Spencer) have been detailed to make a geologic and mineral reconnaissance of the Island of Cuba.—The Coast and Geodetic Survey steamships. Pathfinder and McArthur, at San Francisco, and the Patterson and Gedney, at Seattle, are now fitting up, under orders to proceed to Alaska to survey important passages among the islands along the Alaskan cost.—Dr. Patrick Geddes, who was responsible for the formation of the International Association for the Advancement of Science, Arts and Education, and the holding of an International Assembly at the Paris Exposition, last year, proposes a similar assembly, in connection with the exposition and congresses to be held at Glasgow this year.—The second Latin-American Scientific Congress opened its two-weeks' session at Montevideo on March 20, with over 200 delegates in attendance. Dr. Robert Wernicke, professor of pathology in the University of Buenos Aires, Argentine Republic, was elected president of the Congress.—In order to make the free distribution of seeds by the United States Department of Agriculture as useful as possible. Secretary Wilson has secured authority to send out young trees as well as seeds.