too large demands on the available space of this journal, I will conclude with one further general consideration. Professor Newcomb closes his article with the statement of an objection against state intervention, based on the observation that our congressmen, and I suppose our rulers in general, are not a very wise body of men, and presumably do not know better than others what is for our good. This shows, it seems to me, a total misapprehension of the question involved. Nobody wants to intrust certain things to the government because the government is very wise and very good. Nobody desires paternal government. Even the extreme socialist does not desire it. What he wishes, and believes practicable, is a fraternal commonwealth. The question involved is not, "Shall we let wiser and better people than we attend to our affairs for us?" but "Shall certain functions be performed by co-operative methods, or by individual methods?" for the state is only a certain kind of co-operative institution. Then, if we decide on co-operative methods, shall we adopt voluntary co-operation, possibly that of a corporation, or shall we adopt the compulsory co-operation of the state? Now, inquiry shows that certain functions are adapted for individual effort, that certain others will be best performed by voluntary co-operation, while still others can be accomplished most advantageously by the compulsory co-operation of the state or of some subdivision thereof. What these are, space does not permit me to say in this place. I have, however, laid down a few simple rules elsewhere; Prof. Henry C. Adams has gone into the subject far more at length in his paper, "Principles that should control the interference of the states in industries;"" while valuable suggestions may be found in the admirable monograph of Dr. James, on the "Relation of the modern municipality to the gas-supply," just published by the American economic association. It is enough, if in this series of articles the general points of view of the new school can be impressed upon the readers of Science. It may be remarked, however, that 'interference' is not so good a as 'participation' to denote the activity of the state; for it is not opposed to, but, if wise, in the line of the desires of the people, and precisely on that account it is not generally noticed how large is its sphere. word Finally, the case is not nearly so hopeless as one 1 In my 'Introduction to the labor problem,' published by Harper and Brothers, 1886. 2 A lecture printed in pamphlet form by the Constitution club of New York. would gather from Professor Newcomb's observations. Experience, sooner or later, teaches the people many wise things. It is the function of the economist to help the people by more careful observation, and thus to shorten the term of unfortunate experimentation, and to lessen the cost of that dear teacher experience.' Take the case of the post-office. Experience and science have decided that its functions should be performed by public authorities, trial having been made of private enterprise. That question is settled, and the benefits of correct practice are inestimable. Take the case of letter-carriers in cities. They are a great saving and convenience. I suppose, in a city like Baltimore, the time they save to citizens must amount to hundreds of years in each year. The benefits derived from letter-carriers are equal to those of great inventions, but they have been demonstrated, and are secure. I think the railway problem, now prominent, will be settled in the same way; that is, by experience, aided largely by science. It is not necessary that the majority, or even a great many, that is, compared with the entire population, should have special and profound knowledge in economics in order to secure intelligent economic action. The influence of two or three men 'who know' is enormous when exerted at the right time and in the right place. I suppose six men in congress who thoroughly understood public finance could, at the beginning of our late civil war, have shaped the financial policy of government for years to come. I wish again to call attention to the forcible illustration to which allusion has already been made. A few months since, the question was raised whether the gas-works of Philadelphia should be sold. Few understood the question; and it is said that a systematic agitation in favor of private works was conducted by a vast corporation, which had its eyes fastened on them as a mine of wealth. But there was one man in Philadelphia who did understand the question in all its bearings, and that was Dr. James. He came forward and set the matter in its true light, and I have been told that his influence was decisive. At any rate, it had weight, and the gas-works remain to-day the property of the municipality. That decision was worth many millions of dollars to the city of Philadelphia, and is an illustration of the value of the higher education. All that the University of Pennsylvania ever cost the citizens of Philadelphia, either in their private or public capacity, is a small matter compared to the value to that municipality of a single man who occupies a chair in that institution of learning. RICHARD T. ELY. THE EXISTENCE OF A MAGNETIC SENSE. SINCE the day when Thales, about twenty-four hundred years ago, rubbed a piece of amber on silk and found that it attracted light particles, the phenomena of magnetic action have been regarded with feelings of awe and mystery. The strange entrancing of animals brought about by an intense fixation of their gaze was referred to 'animal magnetism,' because nobody understood either the one or the other. The discovery of the magnetic needle, and its mysterious constant pointing towards the north, added another element to the wonders of magnetism. Mesmer was keen enough to see, that, by explaining the hypnotic phenomena to which he gave his name as due to magnetism,' he was treading on safe ground. That elastic cabinet of mysteries could easily be made to accommodate another series of peculiar facts, and the theory had thenceforth a habitation and a name. The mere mention of socalled magnetic cures is sufficient to suggest a host of alleged facts and wonders. Although all such phenomena assume that the human body is susceptible to the influence of the magnetic field, Baron Reichenbach, in a series of experiments since become famous, was the first to attempt a scientific proof of such an influence. He thus described his 'sensitives,' who were variously affected by the presence of a magnetic field: some saw flames issuing from the poles; some had disagreeable organic sensations; some were benefited by it; and so on. These experiments were repeated by Professor Barrett of the English Society for psychical research, but altogether with negative results, until the young men who had done such good service in the thought-transferrence department were called in to describe the effects of a magnetic field upon them. They saw the lights issuing from the poles, and felt the pains in the temples when very near the magnet. Before these experiments, Sir William Thomson had expressed the opinion that it would certainly be strange if no magnetic sense existed. The fact that nothing happened when he put his head between the poles of a powerful magnet, he regards as very wonderful. Finally, French observers have recorded the fact that hypnotics who have responded to the suggestion that one-half of the body is affected in a certain way (e.g., one arm is insensitive) will have the affection transferred to the other side of the body, and removed from the first side (i.e., the other arm will become insensitive), by the application of a magnet on the opposite side of the body. The above hasty sketch of what has been done towards solving the question of the possible effect of a magnet on human nerves seems to suggest that a rigid scientific test upon normal persons is highly desirable. It was to supply this want that the experiments about to be described were undertaken. The special points which were borne in mind were, 1°, to exclude the action of chance; and, 2°, to rule out all possible modes of suggestion as to what was going on. We believe that we accomplished these objects by using the following method and apparatus. A large and powerful electro-magnet was tipped on its side and supported between two tables. The head of the person to be tested (to be called 'the subject') was placed between the poles of the magnet, with the forehead and back of the head all but touching the poles. He was seated upright in a chair, with his head in a normal and fairly comfortable position. The magnet and the subject were on the third floor of the building. In the room on the ground-floor there was a dynamo-machine, which, when turned by the operator, generated the current. The magnet was connected with the dynamo by heavy insulated wires passing out of the windows and along the wall of the building. The subject and the operator communicated by a system of telegraphic signals: otherwise they were completely isolated from one another. At the first stage of the experiments the following method was employed. After the operator had received the signal that the subject was ready, he did one of two things: 1. He turned the current on, and when, after a short interval, the subject signalled Change,' he turned it off, turning it on again when the second 'change' was signalled; 2. He began by doing nothing, turned the current on at the first 'change,' and off at the second. In either case he received a signal from the subject when the observation was concluded. In each observation the subject knew that the condition of the magnet at the beginning and at the end of the experiment was the same, but that in the middle, between the two 'changes,' the time of which he himself directed, the condition was different. His object was to tell whether the magnet was on or off at that intermediate time. His opportunities for judging were extremely favorable, for he knew exactly when to expect the sensation of a change from one condition to another; and he knew that in one case it would be change from magnetization to demagnetization, and in the other case a reverse change. He had simply to tell which was which. It is evident that by mere guesswork he would answer correctly one-half the time, for he had only a choice between two things, one of which was right and the other wrong. The number of correct answers above one-half the total number of answers would measure the magnetic sensibility. 1 The experiments were conducted in the psycho-physical laboratory of the Johns Hopkins university. Dr. G. H. F. Nuttall was associated with me in the work. Experimenting in this way, we were surprised to find that considerably more than one-half the answers were correct. Apparently the magnetic sense was there. But it was soon observed that we more or less consciously judged by the sound that the turning of the dynamo transmitted along the wire, and thus to the magnet. When the attention was once directed to this point, the doings of the operator could be correctly told every time. After many failures, we succeeded in eliminating this sound by cutting the wires, and inserting one end of each into a mercury-cup, and connecting the other by a binding-screw with the cup. The wires were suspended from the ceiling by silk threads, and inserted freely in the mercury: in this way the sound-vibrations were transmitted to the mercury, and only very weakly taken up again by the wire. This arrangement was inserted in the circuit once in the basement room, and again on the sill of the window, as the wires passed the second floor of the building. The turning of the dynamo was thus rendered inaudible; and for a time the results were negative, the number of correct answers being just about one-half of the total number of experiments. But soon the correct answers became more and This time more frequent. the indications were more subtle. As is well known to physicists, the magnetization and demagnetization of a powerful magnet produce a molecular crepitation throughout its mass, which gives rise to a very faint but audible click. It was this click, and not the magnetic sense, that told us when the current was being turned on, and when off. It is remarkable that we used this click as an indication of the condition of the magnet long before we were distinctly conscious of its existence. This click could not be heard every time, but, with the attention sharply focused, almost every time. But it will be objected, as the click accompanied each 'change,' it could not guide the judgment of the subject. This objection would hold were it not that the click accompanying demagnetization is much more pronounced than that accompanying magnetization. In fact, the latter could rarely, if ever, be distinctly heard. These difficulties were obviated by a slight alteration in the mode of experimentation. At the beginning of each experiment the current was off; at the signal of Change,' the current was either turned on or left off. The subject had then simply to decide whether, on the whole, something had been going on during the experiment, or whether the dynamo had not been turned at all. In this way, only the magnetization, and never the demagnetization, occurred in the experiments, and the click was thus avoided. Moreover, to completely guard against the very slight click of magnetization, the current was not made as formerly, by the closing of a key; but, with a key always closed, the dynamo was turned with gradually increasing speed. It is the suddenness of the magnetization that produces the click. It is evident, that, as before, the chances of a correct guess are just onehalf. The opportunities for judging are perhaps not as favorable when only one change is made, but it is doubtful whether even this difference is appreciable. It is this latter method that was used throughout the rest of the experiments. In all, ten persons, all students in good health, were experimented upon, including Dr. Nuttall and the writer. The results are given in the following table : This table makes it evident, that, in the case of those experimented upon, no sensibility for a magnetic field existed. This still leaves the question open, whether there may not be a morbid sensibility for such an effect; but it makes such a possibility less probable, because the sensibility for a magnetic field ascribed to 'sensitives' is so intense, that some slight remnant of it might be expected to exist in normal persons. It was intended to test persons who were good hypnotic subjects both in the normal and the hypnotic conditions, but no opportunity offered itself. Our conclusions refer only to the question of a normal magnetic sense. On what ground the alleged magnetic phenomena are to be explained is another and more delicate question: that the imagination is a powerful and important factor is beyond doubt; and when, as is generally the case, morbidly sensitive patients, especially hysterical girls, are experimented upon, the merest trace of a suggestion, unconsciously given, of the desired or expected effect, is enough to bring about all the phenomena of 'transport,' etc., for which the magnet has been held accountable. Only when tested under rigid and scientifically controllable conditions can the evidence of such abnormal sensibility be relied upon. Even the precautions against indications as above described would probably have to be added to, if hypnotic subjects were experimented upon. In conclusion it is desired to lay stress not only on the negative character of the results, but on the method employed, and especially on the fact, that, as the precautions were rendered more and more effective, the negative character of the conclusions became more and more evident.1 JOSEPH JASTROW. LONDON LETTER. No more interesting and valuable report has been presented to parliament during the recent session than that of the inspectors of explosives for 1885. Colonel Majendie and his colleagues have been engaged for ten years in protecting the public against the most terrible dangers to which modern science has exposed it. A list of twentynine men is given who have been caught and punished for complicity in what are usually known as dynamite outrages. In 1885, 133 ordinary explosions due to accident came under the notice of the Home office, and some almost incredible stories are told of carelessness in connection with explosives. The explosion of tablets of chlorate of potash in the pocket of a gentleman in Brookline, Mass., who dropped his watch upon them quickly, is characterized as the most curious explosion of the year. Among other 'explosive medicines' is mentioned nitro-glycerine, which is made up with lozenges, etc., for use in cases of angina pectoris and other complaints. In the United Kingdom, 22,268 houses are registered for the keeping of explosives. It is the duty of the local authorities to see that the provisions of the act are complied with. Sometimes, however, they are very remiss, and the inspectors act as a useful check upon them. In 1885, 392 places where explosives were kept for retail sale were inspected, and in some cases they were found to be 'about as bad as they could be.' London, Liverpool, Bristol, Birmingham, Sheffield, Huddersfield, and Bath are selected for special commendation in this respect. At the last meeting of the London section of the Society of chemical industry, a very valuable paper was read by Dr. Meymolt Tidy on the chemical treatment of sewage. Premising that 1 The above is simply a general account of the experiments. For a detailed account, the reader is referred to the full paper on the subject, to appear in the next number of the Proceedings of the American society for psychical research. he had for many years read every thing he could get hold of on the subject, and had also gained practical personal experience therein, he defined sewage as "the refuse of communities, their habitations, streets, and factories." Its very complex nature was commented upon. Two elements were constant, and 'the rest nowhere:' viz., 1°, excreta (every thousand people gave, on a very large average, 2,640 pounds of liquid, and 141 pounds of dry, sewage daily); 2°, roads (if woodpaving be excluded, road-washings contained, on an average, 280 grains of solid matter per gallon, of which 120 were in solution). The extreme difficulty of obtaining fair samples was amusingly commented on; and the salutary effects on sewage, of air and of dilution, as shown by the appearance therein, or otherwise, of comparatively high forms of microscopic life, such as the Vorticella, Rotifera, etc., was pointed out. An unfailing characteristic of sewage was the presence of hairs of wheat, and of free spiral cells, their casing having been dissolved in digestive processes. Authorities were agreed upon two points; viz., that the valuable matters were in solution, and the offensive in suspension. Irrigation could not be relied on for giving absolutely continuous purity. Of the precipitation processes, those in which lime and alumina were employed successively, gave the best general results; and the smell still remaining might be entirely got rid of by causing the effluent to flow over a little land. This combination was probably the best method of dealing with liquid sewage; but, in Dr. Tidy's opinion, the whole system of water-carriage of sewage was a mistake. It was absurd to take expensive and elaborate precautions about purity of water-supply, and then only to use one-ninetieth of this for drinking, allowing the rest to be polluted. The dry-earth system of dealing with human excreta was the only proper and scientific method. The second, and ladies', conversazione of the Royal society was held on the evening of June 9. Many of the objects of interest exhibited at the former one were on view again. Among the novelties were the following: some microscopic sections, diagrams, and specimens illustrating the alteration artificially produced in vitreous rocks by the action of heat alone, by Mr. F. Rutley; floral studies in Chili, of orchids, nests, etc., by Miss North; illustrative diagrams of and specimens from Roraima; some rare earths from Samarskite, Gadolinite, etc., with illustrations of their phosphorescent spectra, by Mr. W. Crookes; pumice, volcanic ash, drawings, diagrams, etc., illustrative of the great volcanic eruption, by the Krakatoa committee of the Royal society; apparatus employed in the examination of air for micro-organisms, by Dr. Percy Frankland; and a remarkable collection of gems, by Mr. Bryce Wright. Photographs of celestial phenomena and microscopic sections of devitrified rocks were exhibited in the lime-light-lantern, and demonstrated by Mr. Norman Lockyer, Mr. Common, and Mr. Rutley; and the United telephone company had established temporary communication with the Savoy theatre, where The Mikado' was being performed. The annual meeting of the Marine biological association was held on June 8, Professor Huxley, the president, in the chair. The council's report mentioned a small increase in the number of members during the year, and the progress that has been made with the plans for the new laboratory at Plymouth, which will be commenced immediately. It is hoped that it may be in working order by the autumn of next year. Much interest is taken in it by the residents of Plymouth, one of whom, hearing that the council of the association were contemplating the omission, for pecuniary reasons, of certain desirable features in the building, has generously offered to provide the five hundred pounds necessary for the purpose. A large amount of valuable zoölogical work has been recently carried out by the Liverpool marine biology committee, which was established some two years ago. The shallow water off the coast of North Wales and round the Isle of Man has been systematically explored with the dredge, with the following very gratifying results: whereas only 270 species of marine invertebrates were known from this neighborhood before 1853, 913 species are recorded in the report of the Liverpool committee. Of these, 235 were not previously known in the locality; 16 are new to British seas; while 7 species and 3 varieties are new to science. W. London, June 14. NOTES AND NEWS. THE Lackawanna institute of history and science, recently founded at Scranton, Penn.. has taken steps for the purchase and preservation of the two great glacial pot-holes found in the Lackawanna valley at Archbald. An illustration of one of these pot-holes was published in Science for Dec. 19, 1884. The second one has not yet been cleared out, but will be cleared by the Lackawanna society. These holes are described by Professor Branner in his recent paper upon the glaciation of the Wyoming and Lackawanna valley. - The destructive effects of poisoning by phosphorus are narrated in a paper read at a recent meeting of the Ohio state medical society by a physician whose practice has been large in one of the most extensive match-factories of that state. He finds that the head of each match contains about a seventieth of a grain of phosphorus, and that the injurious results of the process are most marked among those who work in the dipping and packing rooms. The affection is a disease of the bones of the jaw known as necrosis. In some it appears within two years after they enter the factory; in others its appearance is more delayed. Operatives with unsound teeth are the most susceptible. He recommends that only persons possessing sound teeth be employed in these two rooms; that thorough ventilation be provided in all parts of the factories; that the operatives be not permitted to eat their meals within the factory or with soiled hands; and, finally, that mouthwashes of the alkaline carbonates be freely used. - O. P. Jenkins was elected, June 23, professor of biology, and curator of the museum at DePauw university, Greencastle, Ind. -The Sanitarian records an instance of flies acting as sanitary inspectors. In one of the rooms of a residence in an eastern city, offensive odors were detected, but their exact source could not be located. The carpets were raised, and a carpenter engaged to take up the entire floor. At this moment a friend who chanced to come in, suggested that an appeal be made to the instinct of the fly. Two blue-bottles were brought from a neighboring stable, and the doors and windows of the room closed. The flies soon settled upon one of the cracks in the floor, and, when the boards were raised at this point, a decomposed rat was found. The Japanese disease beri-beri, or kakké, is now regarded as a contagious disease, having for its cause a microbe. The infection enters through the intestinal canal, and locates itself at this part of the economy. LETTERS TO THE EDITOR. Correspondents are requested to be as brief as possible. The writer's name is in all cases required as proof of good faith. The flight of the flying-fish. THE question, among naturalists with whom I have been associated, as to whether or not the flying-fish flaps its wings during its flight, was at first a great surprise to me. My years of sea-service, without hearing a single doubt upon this point, had been exclusively among seafaring men, who are generally positive: naturalists seldom are. Nevertheless, association with the former teaches one that their 'opinion' on a subject is, as a rule, a confirmed belief. In the region of the Cape de Verde Islands, where a very large species of flying-fish is abundant, it is easy to observe the beating of the creature's wings; |