lent to the de novo origin of cases of disease which afterward are chiefly communicated by the first and succeeding cases.

Having settled that such origins do take place, we shall then pry into the secret of the laws of combinations and the conditions which favor the evil evolution or the facts of hybridism, and seek to combat these by starting similar processes in opposite directions, or by sterilization, neutralization, disinfection, and all the details of radical sanitation.

Such a view of the occurrence of old or new diseases, and of the reasons for fixity in some and changing forms and types in others, leads to several practical results.

1. The study of parasites, or germs, as they are called, is only one of the methods of informing ourselves as to the phenomena of disease, and in itself is not likely to be the key to rational and successful treament.

2. Our attention should be directed, far more than now, to the study of conditions and circumstances under which new forms appear; to the influence of persons and surroundings, instead of to the mere finding of a specific form. The latter would, of course, be most valuable as one of the facts in the chain of evidence, but we should not, as now, seek so much to look to it as the cause of disease as to inquire what conditions have caused this or that particular microphyte to be present.

3. We should be able to account for the occasional occurrence of a disease independent of any previous case, and for changing types of disease and new diseases, and would come to treat diseases less by their names and more in view of their type and the effect of surroundings upon them.

4. The tendency of all this is to magnify the importance of close observation, and to lead us to feel that success in warding off disease, and in treating it when it appears, depends mostly upon close observation and that experience which is derived from actual practice.

If we are looking to the biological laboratory for the natural history of disease, or to the chemical laboratory for the application of remedies, we shall surely fail. It is not so much that we need to find the specific germ or the specific methods. The world is always looking after specifics. But the science and art of sanitation has far more to expect from a study of the conditions of persons and surroundings under which diseases, or types and modifications of disease, manifest themselves, as also from a study of the prevention or obliteration of such conditions, than it has to expect from the finding of microphytes as the source of disease, and seeking to cure disease by expelling micro-organisms or attenuating them.

Our only design in this paper is to awaken inquiry as to modes of accounting for the localized origin of disease, without any antecedent case, on the proposition that the laws of evolution, environment, hybridism, or modification by culture, give rise to diseases so different from their prototypes as to have individuality and permanency of their own.

Because such inquiry is relevant to prevention, there is good reason to believe that by ascertaining the laws of these transformations and modifications of type and of the origination of special varieties, we shall ere long find new means for the prevention or limitation of many diseases.

This

'The Malarial Germ of Laveran' was the title of a paper read by Dr. William T. Councilman of Baltimore. He considers that this organism probably belongs to the Protozoa, a group of unicellular organisms noted for the varied changes of form which the individual examples undergo in the course of development. Of the malarial germ there are ten more or less distinct forms, of which five are always found in intermittent-fever. During the chill of the fever a definite form is seen, in which multiplication takes place by segmentation. One form has actively moving filaments. was found in blood taken from the spleen in ten cases of malarial cachexia, and in five cases of intermittent-fever. Dr. Councilman says that too much importance cannot be assigned to this organism as a means of making a differential diagnosis between malarial-fever and typhoid-fever. In outbreaks of fever which occur in small country-towns, where it is of the greatest importance that the character of the disease should be recognized promptly, the advantage of this mode of diagnosis is most evident. There is too much

reason for believing that in localities where malarial-fevers prevail, epidemics of typhoid-fever are frequently mistaken for fevers of a malarial type.

Mr. H. Lomb of Rochester offered prizes of $500 and $200 for the best essays on practical sanitary and economic cooking adapted for persons of moderate and small means. Dr. LaBerge, healthofficer of Montreal, described the system employed in that city for the collection of garbage, and for its destruction by the Mann furnace. Committees were appointed on State boards of health, pollution of water-supply, disposal of garbage, animal diseases and animal food, forms of statistics, incorporation, protective inoculation, Lomb prize essays, national health legislation, and improvement of the sanitary and medical service on emigrant ships. It was decided to hold the next meeting of the association at Milwaukee. The following officers were elected for the ensuing year: president, Dr. Charles N. Hewitt, Red Wing, Minn.; vice-presidents, Drs. G. B. Thornton, Memphis, and Joseph Holt, New Orleans; executive committee, Drs. Henry B. Baker, Michigan, S. H. Durgin, Massachusetts, and J. N. McCormack, Kentucky. The secretary, Irving A. Watson, M.D., of Concord, N.H., holds over.

THE SURFACE-TEMPERATURES OF THE OCEANS. A NUMBER of researches on the surface-temperatures of the oceans,which have recently been published, throw a new light on this complicated phenomenon. The maps accompanying the present number of Science have been constructed according to Dr. O. Krümmel's maps, showing the surface-temperatures of the oceans. As the Arctic Ocean must be considered part of the Atlantic, of which it forms the most northern extremity, it was desirable to include it in the map. Besides this, the Antarctic Ocean exerts a great influence upon the southern part of the Atlantic Ocean, and therefore the latter has also been included in the map, which shows two-thirds of the earth's surface in a perspective projection. The lateral parts, however, have been left off, as they do not belong to the system of the Atlantic Ocean. The Pacific Ocean has been constructed in the same way, the map extending from its northern limits to the entrance of the Atlantic Ocean. The latter map makes it very clear that the Pacific Ocean forms a comparatively well-defined basin connected by narrow straits with the basin of the Atlantic and Indian Oceans. Its southern limit is indicated by the east coast of Australia, Wilkes Land, Graham Land, and the southern portion of America.

A glance at the lines showing the surface-temperatures of the oceans reveals the remarkable fact that the warm water is accumulated in the western parts of the oceans. Krümmel designates water of more than 24° C. (75° F.) as 'tropical water.' In August the belt of such water is 21 degrees of latitude wide in the eastern part of the Atlantic, while it occupies 61 on its western side. In February it is 22 degrees wide in the eastern part, while it is 56 degrees wide in the western. In the Pacific Ocean it does not occupy more than 17 degrees in August and 25 degrees in February, while in the western parts its width is 57 degrees and 49 degrees respectively. In comparing the amount of tropical and extratropical water, Krümmel finds that twenty-nine per cent of the whole surface of the oceans has always a temperature of more than 25° C., while almost one-half of it temporarily attains this temperature.

It will be observed that in certain parts of the oceans the lines of equal temperature are much crowded, and show sharp angles. This is entirely due to currents, which carry warm water to high latitudes, and cold water to warmer regions. Thus the influence of the Agulhas current may be observed in the sharp angles of these lines near the Cape of Good Hope, while the cold Cape Horn current lowers the temperature along the eastern coast of South America. The influence of the Gulf Stream may be seen in the crowding of the lines of equal temperature near Newfoundland.

The accumulation of warm water in the western parts of the oceans is entirely due to the action of the trade-winds, which blow continually from the eastward, and drive the warm water of the ocean westward, where it is accumulated on the coasts of the continent. Buchanan has explained this phenomenon in a paper on similarities in the physical geography of the great oceans, which has been published in the Proceedings of the Royal Geographical

tor and towards the west. At the same time the surface-water is evaporated, and thus becomes more concentrated than the deeper and colder layers. In consequence of its greater salinity, the warm surface-water sinks to a certain depth, and thus conveys its higher temperature to the deeper layers. Thus the western parts of the ocean are supplied with water of high temperature, which is collected in the Atlantic Ocean in the immense bay formed by the coasts of North and South America.

Another remarkable fact is shown in our map. It is the prevalence of cold water along many coasts. In South Africa we see the line of 16° C. (61° F.) extending far northward, and on the

amount of material has been contributed by numerous investigators. Among these, I mention Buchanan's researches in the region of the counter equatorial current on board the 'Buccaneer,' Captain Hoffmann's observations off Cape Guardafui, and Dr. G. Stapff's off Angra Pequeña in South Africa. All these observations tend to show, that wherever the prevailing winds are blowing off the shore, and the water is thus removed without a possibility of being replaced by superficial currents, cold water rises to the surface. But it has been pointed out in an essay published in the Annalen der Hydrographie, that, wherever a current is deflected from a coast, cold water must rise to the surface. This fact accounts for the low

temperature off the west coasts of California and South America. A number of profiles showing the temperatures of the Pacific Ocean off the coast of California, which were published by Dr. C. M. Richter in the Bulletin of the California Academy of Sciences, show very plainly the rising of cold water near the shore; and although the author tries to prove, by means of these charts and profiles, the existence of a cold current, they seem to be far more in favor of the theory advanced above.

It will be seen that in the equatorial parts of the Atlantic Ocean two regions of remarkably cold water occur. One of these is on the coast of Guinea; the other, east of St. Paul. Krümmel believes that they are also due to a submarine source, the cold water of the depth taking the place of the warm dense water which is driven westward by the wind. He points out that it is situated between the equatorial current and the counter equatorial current, and that thus the cold water supplies a deficiency caused by two currents flowing in opposite directions. Therefore this area of cold water does not exist in February, when both currents are less strong. The Guinea current he considers entirely caused by the southern equatorial current, and as supplying the Gulf of Guinea with water instead of that which is drawn from it by the southern equatorial current. We ought to point out here the fact shown by Buchanan, that all counter equatorial currents are very superficial, that their velocity is the greater the less the density of this water, and that the isothermal gradients are very great below these currents, as the light water of the surface prevents the heat from penetrating into the ocean.

The problems of the equatorial circulation of the oceans is extremely complicated, and the observations mentioned above show that the vertical as well as the horizontal circulation of the waters must be studied. The dynamics of the counter equatorial current are particularly obscure, and a careful investigation of its density, temperature, and strength is very desirable.

MENTAL SCIENCE.

The Mechanism of Attention.1

VOLUNTARY attention is an artificial act: it grafts itself upon spontaneous attention, and takes its nourishment from this. In spontaneous attention the object acts by its intrinsic power; in voluntary attention the subject brings an alien power to bear upon the process. Spontaneous attention represents the maximum of attraction between subject and object; voluntary attention, the maximum of resistance. It is the voluntary form of attention that is here to be considered.

In the first place, how is so artificial a process as voluntary attention brought about? The method, says M. Ribot, is to make attractive artificially what is not so naturally; to arouse an artificial interest in things naturally uninteresting. The process by which this is done is infinitely varied, but consists always of arousing an interest by playing upon some emotional state.

The infant, according to Preyer, at first is under the sway of spontaneous attention alone: it looks only at bright objects, at sustenance-giving objects. At about the end of the third month it explores the field of vision, and glances at less and less (selfishly) interesting objects; and it is the same with the other senses. The path is from the most intense, most impressive sensations to the finer, more delicate ones. The child naturally 'flits from one sensation to another: to fixate and hold one sensation is an art that must be learned. A child, for example, refuses to learn to read, but is vastly interested in the pictures in the book. The father says that reading will show the meaning of the pictures. This acts as an artificial inducement, and the child goes to work, substituting an artificial attention to arbitrary signs for the natural attractiveness of pictures. M. Ribot distinguishes three periods in this substitution process. In the first we can appeal to bodily feelings alone. The child can be taught voluntary attention only by playing upon its fear, its egoistic tendencies, by rewards, sympathetic emotions, natural curiosity. In the second period the emotional nature is still the most powerful motive, but the kind of emotion is higher. One can here appeal to ambition, to emulation, to duty. In the final period the attention is maintained by habit. The student at his 1 A résumé of an article by Prof. Th. Ribot (v. Science, No. 252).

desk, the workman at his shop, often wish they were elsewhere; but the habit as formed by past appeals to pride, ambition, etc., chains them to their tasks. Art has done its work, and attention has become second nature. Granted a certain environment, and the work goes on almost of itself. Many persons never reach this third organized stage of voluntary attention: there is a vast body of unsteady, Bohemian, vagabond types of character in whom voluntary attention is sporadic only, and not habitual.

The training of animals proceeds by the same steps. An ape is taught to do things meaningless to it by connecting such acts with rewards and punishments. The factor of attention in the process is well shown, in that such animals are selected for training as most readily attend amid distractions.

The genesis of voluntary attention is to be found in its utility. When the conditions of life become at all hard, and especially if they become so by more or less sudden changes, the power of adaption to them is dependent upon voluntary attention to details ; upon consideration of something besides the immediately attractive and useful. The savage is lazy, is inspired only by chase, by war, by play; his interest is in the unknown, the unforeseen, the chance. He is not capable of continuous labor. In half-civilized communities work is repugnant. Voluntary attention is a factor of civilization, and is maintained with effort. The most constant characteristic of criminals is lack of power to pursue a steady calling; and the Italian anthropologists regard this as a reversion to primitive habits. Voluntary attention thus came in, and is maintained as a sociological power.

While we all have quite a definite notion of the feeling of effort in fixing the attention, the nature of the process escapes our observation. We feel that the struggle is to focus the thought upon one topic to the exclusion of others, all knocking for admittance into consciousness. The question is not, 'How does a concept come to be attended to?' but How is it maintained in the focus of attention? How do we inhibit other concepts?' The answer is very incomplete. The physiology of inhibition is in its infancy. The fact itself simply states that the excitation of a nerve may not only produce motion, but may cause a motion to cease. Stimulating the pneumogastric nerve arrests the heart-beat. The highest form of this power of inhibition is attention: this Ferrier locates in the frontal lobes of the brain. The intelligence would thus be proportionate to the development of these lobes; stimulation of them would never produce movements; and their disease would cause no paralysis, but a lowering of the mental life. All this is found to be true. Inhibition is likewise late in appearing, coming long after impulsive will in child-development. We know only the initial and final steps of the process, the will not to do an action, the fact that it is not done; but we have good reason to believe that the muscles play an active rôle in the process.

Attention may be fixed upon three kinds of mental objects, — perceptions, images, ideas. In perception the dominance of the motor element is evident. In seeing, touching, etc., there is always a motion; and the law that the more mobile the part the more sensitive it is, is quite a general one. To fixate an object steadily without moving the eye soon reduces the field of vision to a blank ; a weight constantly pressing upon the skin is soon not felt. Consciousness is always of change, and change is based upon movement. Attention is the repression of foreign, irrelevant movements and the concentration upon pertinent ones. Distraction is a diffusion of movements. Next with regard to images. Here the attention is turned inwards, and becomes reflection; but the motor element has not been lost. The motor element of the perception is only weakened (not lost) in its recollection. The two processes are the same in kind, and differ only in degree. As the vividness of the recollection increases, it approaches the perception in the prominence of the motor element. The intense thought of falling down an abyss has led some persons to throw themselves down. Mind-reading is really muscle-reading. When we pass to ideas (and especially abstract ideas), the problem is more difficult. M. Ribot confines his attention to three types of ideas. The first are such as are formed by the fusion of like images without the aid of a word. Their type is the idea of a class, a species. This is within the grasp of animals, children, and deaf-mutes. It is a generic image, like a composite portrait. Here the question as to the motor

element is unnecessary, because there is no voluntary reflection involved in attaining this idea. The second class includes the fusion of images in different objects, still without the aid of words, and is represented in the common abstraction. This is a much higher process, and many peoples have stood still at the early stages of it. The Fuegians have no abstract terms; the Indians have words for 'red oak,' for 'white oak,' but not for oak' in general; the Tasmanians have words for different kinds of trees, but not for 'tree.' In all these processes there is a motor element in the word, and perhaps in the image too. Finally, as the image becomes more and more abstract, the word becomes more and more fundamental. That the word contains a prominent motor element (varying, however, in its strength in different persons) is generally accepted, and is shown by the fact that this element in language can be lost while the rest remains unlost.

We are thus led to the conclusion that thought without motion is impossible; and, though we cannot have the opportunity of demonstrating this absolutely, we can make it extremely probable. Severe activity is incompatible with intense thought. To direct one's attention is work, and the less natural interest in the topic the more fatiguing the strain. It is not a purely mental process, but is connected with nerve-activity and such movements. Monoideism is work, destruction is rest.

Finally the hints as to the action of attention to be derived from experimental study should be noted. In re-acting to a stimulus, the time is shortened when the attention is fixed, and is lengthened when the attention is wandering. So, too, the more cultured classes can re-act more quickly than the ignorant, because their power of voluntary attention is drilled. If the physical state prevents sharp attention, the time is lengthened. A headache lengthened a re-action-time from .133 to .171 of a second, and severe fatigue to .183 of a second. In various stages of paralysis the time lengthened to .166, .281, and .755 of a second; while in hypnotism, when there is an extraordinary concentration on one perception, the time was shortened from .328 to .193 of a second. Again: the most influential factor in the re-action-time is the expectedness of the impression. If the sensation is preceded by a signal announcing its approach, the time is much shortened. According as the nature, intensity, and time of the stimulus is known, the time is more and more shortened. The unexpected delays the re-action. Again Wundt has shown that when two impressions—say, the ring of a bell and the movement of an indicator are simultaneous, the one that is attended to gets first perceived. The adjustment accommodation of the attention in all these cases is again a

motor act.

SCARLET-FEVER REPORT. — I.

THE success which has followed from the collective investigation into the subject of distillery-milk and its effects on the lower animals and man when used as food, which was made by Science in June, has induced this journal to undertake other inquiries into similar matters which affect the public health. Correspondence has been opened with a number of prominent sanitarians of the United States, and as a result scarlet-fever has been selected as the next subject for inquiry. The following letter has been prepared, and forwarded to leading sanitarians and physicians, and others:

The prevalence of scarlet-fever in all parts of the civilized world, and the great mortality therefrom, amounting in England alone during five years to 88,273 deaths, have induced Science to institute an inquiry into the reasons for such a condition of things, whether it is a fact that this disease is not amenable to control by sanitation; or whether sanitarians have not suggested any practical method by which it may be controlled; or whether parents, teachers, health authorities, and others neglect to carry out the recommendations which sanitary science has made. With the object of helping to determine these questions, will you kindly answer the following inquiries :

1. Do you believe that scarlet-fever ever arises, at the present time, de novo, as distinct from a pre-existing case? If so, on what grounds do you base that belief?

2. Is there any doubt in your mind that scarlet-fever is a com

municable disease, and, if so, what reasons have you for that doubt ?

3. If you believe it to be communicable, can you give any instances which have come under your own personal observation, tending to prove its communicability? If so, please give them in detail.

4. Have you any information touching the communication of bovine scarlet-fever to man, either by contagion or the milk of the affected animal ?

5. When does a patient who has had scarlet-fever cease to communicate it to others?

6. Can you give any instances which have come under your own personal observation in which clothing, toys, books, or other articles have communicated the disease? If so, please give them in

detail.

7. How long have you personally known such articles to retain the infection?

8. Should boards of health require reports of cases of scarletfever to be made to them, and, if so, by whom and why?

9. What is the duty of boards of health if such reports are received?

Io. Is there any plan which, if put into execution, would, in your judgment, prevent the spread of scarlet-fever?

II. If so, can you give instances in which it has practically done so?

[WILLIAM K. NEWTON, M.D., Paterson, N.J., State dairy commissioner.] Below please find answers to your circular relating to scarletfever:

1. I have often seen isolated cases of this disease beginning at a time when no other case existed in the city. Many times I have seen a single case begin without any probability of an exposure to another case, but I do not think that we are justified in accepting the theory that the disease may arise de novo because of our inability to find the original case. But there is much to lead us to study this side of the question, for filth may be a possible cause. 2. It is no doubt communicable.

3. It is communicable, and scores of instances might be mentioned to substantiate this statement. Cases where children have been exposed at school for a few minutes to one sick with the disease have come under my notice, and, where they have not had the disease before, they have taken the disease in due time. It is a common occurrence for children exposed to the sick to contract this disease.

4. No personal information. The London Lancet during the past two years has contained many articles on this subject. 5. As long as there is any roughness of the skin.

6. Have known of many instances where woollen clothing has been the means of carrying the disease. 7. Three weeks.

8. Yes, if the proper officers are prepared and authorized to enforce strict separation and quarantine. If reports are required, and on receipt by the authorities are filed, or only tabulated, and no repressive measures employed, no good is done; and the reports should not be required, for they only go to swell the statistics without benefit. The attending physician is the proper person to notify the authorities, and for this work he should be compensated. Reports from the householder or the family are not reliable, and are not promptly made. As was said, these reports are for the purpose of enabling the health authorities to restrict the spread of the disease, and, if notification is required, restrictive measures should be followed up.

9. The reports should first be recorded, and the location of the case marked on a map of the city kept for that purpose, the latter entry being a record of location to enable us to ascertain if locality

has any thing to do with the disease. Next the proper officer should be sent to the house to instruct the family in methods of disinfection, and to note the condition of the house. He should leave with the family a circular, issued by the board of health, giving an account of the disease, its methods of spreading, and its dangers, also brief directions for disinfection. On the recovery of the patient, or in case of death, the premises should be disinfected by an officer of the board. People from infected houses must be excluded from school, church, factories, etc., and a strict quarantine maintained until the premises shall have been disinfected. In case of death, the body should be interred as speedily as possible and no public funeral allowed. No person should be allowed to enter the house except the regular attendants.

10. If the above plan is rigidly carried out, it is possible to check the spread of the disease; but at present it is not possible to strictly quarantine or isolate cases of this disease, because many think it a mild one and of little consequence. Again, many cases are so mild that the sick person is not confined to the bed or even the house, and hence mingle with the well, and these mild cases are often not recognized.

11. I know of no instance where the spread of scarlet-fever has been certainly and completely stopped by restrictive measures; but could we enforce rules as rigidly as is done in epidemics of smallpox or cholera, where the public is prepared for harsh methods, it is probable that the disease might be stamped out for a time. 12. I know of none.

[SAMUEL W. ABBOTT, M.D., Boston, Mass., secretary State Board of Health of Massachusetts.]

In answer to your circular relative to scarlet-fever, I have the honor to reply as follows; my reply being based upon an active country-practice of twenty years, and also upon five years' experience as the health-officer, and secretary of this board, during which time I have had opportunity to observe a considerable number of epidemics of scarlet-fever of varying extent and severity.

1 and 2. No.

3. An instance under my observation is the following: A healthofficer visited a public institution for the purpose of giving advice as to preventive measures. While there he saw several children ill with scarlet-fever, in various stages of the disease, and examined them at the bedside. He then returned to his home, a hundred miles distant. On his way home, and before returning to his family, he took the precaution to take a thorough bath, and, on reaching home, sent his clothing to a cleansing establishment. About eight days afterward, three of his children were taken ill with scarlet-fever, one of whom died on the fifth day afterward. There were no other cases of scarlet-fever in the town at that time. 4. A limited outbreak occurred last spring in the town of Wellesley. Four children were taken ill in two families who took milk from one man who had two cows. There were no other cases in the town at that time. One of these cows had an eruption on the udder, which, on examination by a competent veterinary surgeon, did not appear to have the characteristics described by recent English reports. I do not regard this as a conclusive case.

5. Not until after desquamation has been completed, and all germs of the disease originating from the patient have been destroyed. 6. I have no doubt that such is the case, but have no positive evidence on this point.

8. Yes, by the attending physician, who is the only competent authority to judge of the character of the disease. The law of this State makes it incumbent on both physician and householder to report, but reports from the latter are rare.

9. To isolate the sick, and see that proper measures are taken for the continuance of such isolation, and of disinfection upon recovery; and in case of death the funeral should be private.

10. Nothing short of complete isolation of the sick, and absolute destruction of all germs of the disease.

11. The following statistics are suggestive. By circulars, reports of boards of health, public lectures, and by every possible means, the contagiousness of scarlet-fever has been taught, and the community has been led to see the dangerous character of the disease, and its destructiveness as compared with other diseases, until public opinion will tolerate much more decisive measures than were possible twenty years since. The following table (from the

Undoubtedly several extensive epidemics might upset these statistics. I think, however, that the length of time included (30 years), and the size of the population (1,231,067 in 1860, and 1,942,141 in 1885), may be taken as conclusive that something has modified the progress of the disease, the death-rate in the last fifteen years being less than one-half as large as that of the fifteen years previous (1857-71). If the period of ten years 1857-66 be compared with the last ten years (1877-86), the result is still more striking, the death-rate of the latter period from scarlet-fever being less than one-third as great as that of the former period. 12. By remedies. No.

13. I beg leave to mention one or two popular errors in this connection. There is a singular notion that physicians' families are comparatively exempt from infectious diseases. On the contrary, I can call to mind at least a dozen families of country physicians in active practice, within five miles of my present home, which have been invaded by this destructive disease. Another error is the notion that a dead body is more dangerous than a living one. There is no evidence, so far as I can learn, in support of such a notion. One living, breathing body, sick with infectious disease, must necessarily produce more infectious material than a dead one. [R. B. S. HARGIS, M.D., Pensacola, Fla.]

In relation to the questions concerning scarlet-fever stated in your circular, I proceed at once to answer them in order :-

1. I have seen scarlet-fever on two occasions, in an isolated house, no other cases in the city nor in the neighboring places, the source of which could not be traced to any focus of infection outside the walls of the dwellings in which the cases existed. I have also seen measles, a congener of scarlet-fever, undoubtedly a contagious disease, spring up spontaneously, and spread from a single isolated place all over the city, thus apparently arising de novo. Upon careful and anxious inquiry in regard to the above-mentioned instances of spontaneous development of scarlet-fever and measles in isolated places, I was informed that none of the parties in those houses had had any correspondence, by letter or otherwise, or purchased or received any fabrics, or indeed articles of any kind, from persons at a distance anywhere. All infectious and contagious diseases are associated, as a rule, with cutaneous eruptions or glandular