the light of a higher culture, who invented the famous sacred calendar, so long the subject of astonishment to the learned, and who constructed edifices of brick and stone whose massive walls, strange ornamentation and remarkable architectural details, place them among the most impressive of any on the continent.

One of these was described, not for the first time, but with considerable care, by the engineer Aureliano Estrada, in the Memorias de la Sociedad Scientifica Antonio Alzate, of Mexico, last year. It is a mass of buildings crowning the summit of the Cerro de Quiengola, a mountain some 2,500 feet in height in the District of Tehuantepec. It presents thick walls of stone and burnt brick, circular and square towers, truncated pyramids and all the proofs of an extensive population.

It is sincerely to be hoped that these and numerous other remains in this state will be protected from destruction and thoroughly examined to the benefit of science.

The Basques and the Iberians.

An unusual number of papers and essays on questions relating to the ethnic position of the Basques and their possible relationship to the ancient Iberians, have appeared in France within the last year.

First, the linguists have had much to say. It is well known that Wilhelm von Humboldt in the first decade of the present century wrote an admirable analysis of the place-names throughout Spain, showing, he believed, by them, that the Basques at the time of the Roman conquest extended westward from the Prenees to the Atlantic coast. His conclusions have been alternately accepted and denied by special students of the tongue, and so they are to-day. Professor Julien Vinson, for example, a distinguished Basque scholar, says: "There is no historic proof, nor even scientific probability, that the Basque at any time occupied a much larger area than at present. The opinion that the Iberian peninsula or other parts of southwestern Europe were peopled by a race or races speaking a kindred dialect is based merely on etymologies, and must be considered a pure hypothesis."

Directly the contrary is maintained by M. J. F. Bladé who observes: "Inasmuch as, in a large area surrounding the present territory of the Basques, altars are almost daily found inscribed to gods unknown among the Celts, and tombs bearing names certainly not Celtic, the conclusion appears justified that these names are ancient Basque, and that this tongue once spread over Aquitania and Iberia."

Meanwhile, the physical anthropologists have been at work. Dr. Lajard, in the Bulletin of the Anthropological Society of Paris, published the results of a comparison of ancient and modern skulls in the Canary Islands, with a large number from Portugal and Spain; reaching the result, that not only was the race of the Guanches of the Canaries identical with that of the old Iberians, but that both point to the still older race of Cro Magnon, as their near relatives. This does not take in the Basques, but leaves them to one side; while, as we certainly know that the Guanches were blonde Hamites, closely akin to the Ritians at Morocco, it places the Iberians along with the North Africans. As for the present Basque population, they are reported by M. De Cartailhac as losing their language and diminishing in number. Even in the most remote and secluded districts, the deaths are more numerous than the births, owing to the rarity of marriages; and French and Spanish are in a fair way to drive out this curious and venerable tongue from its last refuge in the fastnesses of the Pyrenees.

Man in South America.

There is no part of the world that offers a more curious subject of speculation as to its future than the continent of South America, as was well set forth in an address before the American Geographical Society, by its President, Mr. Gardiner G. Hubbard.

That the Amazon river system alone drains a basin of fertile land, basking under a climate of perpetual summer, greater in area than the whole of Europe, is an astounding fact in itself. This vast territory is practically uninhabited. Its aboriginal

population is disappearing, or has disappeared, and the whites who in sparce number take their place, scarcely pretend to come with the expectation of remaining. There are tracts as large as the whole of France, of which we know less than of any equal area on the globe. Tribes of men are living there who are yet absolutely in the Stone Age, and who, even by barter or distant rumor, never heard of the European race or the use of metals.

The question up to which Mr. Hubbard leads his reader is second in importance to none in anthropology-that of acclimation. Is it possible for the white race, when it shall be endowed with all the resources of art and science which it is soon to have in its grasp, successfully to fight against the terrible odds of a tropical climate? He quotes in his favor the words of the historian, Buckle, and the naturalist, Bates; he might have added others of weight; but it cannot be doubted that most of the medical observers who have devoted themselves to this vast inquiry, lean to the opinion that never will the white race flourish under tropical skies

NOTES AND NEWS.

THE fifth summer meeting of the Geological Society of America will be held Tuesday and Wednesday, August 15 and 16, in the Geological Lecture Room, Science Hall, University of Wisconsin. On account of the World's Congress of Geologists convening in Chicago, August 24, an invitation will be sent to geologists residing outside of North America to attend this meeting and present papers. A meeting of exceptional interest is anticipated. Fellows desiring to read papers should send titles and abstracts not later than July 15, in order to secure insertion in the preliminary list of papers. Matters for the programme, distributed at the first session, should be sent in by August 10. The meeting-room has facilities for lantern views, and members are invited to bring such illustrations. Matter sent by express or mail may be addressed in care of the Secretary, Room 32, Science Hall University of Wisconsin, Madison, Wis. Packages should be clearly marked with the sender's name and prepaid. The excursions offered to the Fellows of the Geological Society of America are as follows: To the Lake Superior Region, to Devil's Lake, to the Dells of the Wisconsin, and to the Driftless Area.

- The Pope Manufacturing Company, of Boston and Hartford, makers of the Columbia bicycles, have engaged of late in a novel enterprise. They offered some time ago to give one of their bicycles to the school teacher who should be most successful in detecting errors in the school books in use in this country, provided the errors were determined to be such either by the authors and publishers of the books or by an impartial board of examiners. Typographical mistakes and disputed points in history and opinion were not to be included, but only errors of fact or of statement which could be shown to be such. Responses came from all parts of the country and the company have already awarded several of their bicycles to the persons who complied with the conditions of the gift The kind of errors detected may be learned from the pamphlet entitled "Errors in School Books," which the Pope Company have issued, and which has now appeared in a second edition. Some of the errors are hardly more than ambiguous statements; others are erroneous dates; while others still are misstatements of scientific fact, as, for instance, the statement in a geographical work that the earth moves around the sun in a circle. Most of the publishers took the criticisms good naturedly, and whenever they were shown to be well founded corrected the books accordingly. The Pope Company have now renewed their offer of a bicycle to each of the five persons who shall send them the greatest number of errors in school books before September 1, 1893, the present competition to be open to all persons and not to teachers alone. That errors in school books are specially mischievous is obvious, since the young people who use the books have not, as a rule, the means of detecting them, and though the class of errors to which the Pope Manufacturing Company have devoted themselves are not perhaps the worst, they are the most easily detected and proved, and we should be glad if this new enterprise might result in the exposure and correction of every one of them.

SCIENCE:

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NOTES ON THE FLORA OF LONG ISLAND.

BY SMITH ELY JELLIFFE, M.D, BROOKLYN, N. Y. THE flora of Long Island is one of some degree of richness, which upon a casual observation would seem to be a somewhat anomalous statement, for it would appear that a sand waste a few miles wide and about a hundred miles in length would hardly be a place upon which a rich or abundant flora could flourish.

Long Island, so geologists tell us, is a portion of the terminal moraine of the glacier that stretched across the country from east to west; traversing the entire length of the island there is a rocky ledge, the so-called "back bone," from which the land falls in more or less steep descents to the north, and in long gradual slopes southward; the whole coast is rich in fresh and salt water marshes, which are more pronounced upon the southern coast.

The earliest notices upon the subject are to found in a paper published in 1807, entitled "Plantæ Plandomensis," or a catalogue of the plants growing near Plandome, Queens County, by Caspar Wistar Eddy. In 1835, J. B. Zabriskie published a "List of Plants Growing near Erasmus Hall, Flatbush," and from 1843 to 1853 John Torrey M.D., in his publication on the Flora of New York," included many Long Island plants. In 1874, E. S. Miller and D. W. Young published their "Catalogue of the Plants of Suffolk County," to which additions were made in the Bulletin of the Torrey Botanical Club. This journal also contains many notes upon the island flora. C. H. Peck, N. L. Britton, A. H. Hollick, Geo. D. Hulst, W. H. Rudkin, W. H. Leggett, J. L. Zabriskie, Mrs. E. G. Britton, Mrs L. D. Pychouska, F. E. Tillinghast and others have contributed notes from time to time upon new or interesting plants found on the island.

In round numbers about 1500 phænogamous plants have been recorded; the work in the cryptogams has been scanty, yet the writer has records of upwards of 750 species, which promises much for the numerical value of this portion of the flora when more completely studied.

he most characteristic of the plants are found in the salt Larshes and along the sands of the sea coast, here are a number of interesting grasses and sedges, including Fuirena squarrosa, Heleocharis Robbinsii, rostellata and melanocarpa, Scirpus subterminalis. Rhyncospora nitens, Calamagrostis Nuttalliana, Glycenaspfluitans, Eragrostis pectinacea and others; the salt-loving plants as Ranunculus cymbalaria, Lecheas, racemulosa, minor and major; Hudsonia tomentosus in quantities and H. ericoides, though much rarer, Prunus maritima and several of the more common forms are constantly to be found at almost all points along the southern shore. In the fresher marshes Spiranthes, Habenaria, Calopogon and Pogonia. Cypripidiun and Goodyera are intermingled with rush and sedge and grass.

Along the ridges and in the higher lands the Composites, Labiates and Graminiæ are widely distributed, there seeming to be a nearly equal distribution throughout the three counties. In general, however, the plants found in Suffolk county are among the most characteristic, there being there some fifty or sixty plants that belong to the New Jersey pine-barren flora and whose presence is to be explained upon the geological grounds that this eastern portion of the island was at one time a portion of the Atlantic littoral plain. Among those plants found in Suffolk county, some of which are also to be met with in Queen county, there may be mentioned Camelina sativa, Reseda luteola, Drosera longifolia and filiformis, Ascyrum stans and Crux andreæ, Arenaria squarrosa, Polygala lutea, Quercus phellos, Cyperus dentatus and Cupressus thyoides, as of more particular interest. Recent investigations by Dr. A. H Hollick, of Columbia College, have been directed to a better understanding of this portion of the flora, and interested botanists are referred to his papers in the Transactions of the New York Academy of Sciences.

The knowledge of the cryptogamic flora is still in its infancy. The ferns are well known and comprise the majority of the common Aspleniums and Aspidiums with here and there a more or less uncommon form, as Woodsia obtusa, Woodwardia angustifolia. The Bryophytes are represented by over 100 species, and it is certain that twice that number will be found when the collectors are more numerous and alert. Catharine a crispa is one of the rarer plants that has been found. The list of lichens is far from complete. 60 species are recorded and hardly a rock lichen collected. The number of species of fungi is 250, also a new field. The best known of the lower cryptogams are the marine algæ, they having been studied from the time of Professor Bailey to the present. Bostrychia rivularis, Callithamnion dietziae, which Professor Farlow, from a study of the original specimens in the herbarium of the Long Island Historical Society, is disposed to regard as a var. laxa of C. Baileyi, Callithamnion tenue are a few of those interesting algæ that are more or less uncommon. The diatoms are represented by a list of 78 species, which, with 45 species of fresh-water alga completes the numerical enumeration of the island's flora. Figures, however, are totally inadequate to express the characteristics of the flora of any region, however sparse it may be in vegetation, and it is hoped that in the near future a flora of Long Island will be in sufficiently advanced condition to warrant its publication, at least the portion recording the distribution of the phænogamous plants.

CONSUMPTION AMONG THE COLORED PEOPLE OF THE SOUTHERN STATES.

BY G. W. BUBBARD, M.D., NASHVILLE, TENN. PROBABLY no greater change in the social condition of a people can be imagined than the transformation of a race from the state of slavery to that of freedom.

The colored people of the late slave-holding States have now been free for twenty-eight years; and their present condition in regard to health and mortality, as compared with that which prevailed before their emancipation, is an interesting question, not only to the physician, but also to the philanthropist and the student of social science.

It is almost, if not quite, impossible to obtain reliable vital statistics concerning the people of the Southern States outside the larger cities and towns; and it is only within a few years that even these have been complete and reliable.

In this article I shall consider only one disease, phthisis pulmonalis; but it may be well to remark that the general death-rate among the colored people in the southern cities, where statistics are attainable, is nearly twice as great as that among the whites. I have made careful inquiries of many physicians who practised in the South before the late civil war, and it has been their universal testimony that pulmonary consumption was a comparatively rare disease among the slave population, some even affirming that it was entirely unknown. It would probably be safe to say that this disease was very much less frequent among the negroes than among the white people.

It will be seen from the above table that the rate of mortality in proportion to 1,000 of population per annum is nearly four times as great among the colored people as among the white. It is probable, however, that consumption is much less prevalent in the country districts.

I will now consider some of the causes that have probably produced this excessive death-rate from this disease.

1. Unhealthy dwellings, often situated on narrow alleys, reeking in filth and moral and physical pollution. 2. Improper food, often of poor quality and lacking in quantity. 3. Insufficient clothing and exposure in inclement weather. 4. Irregular habits and a lack of a proper amount of sleep. 5. Excessive use of alcoholic drink. 6. Ignorance concerning the laws of health. 7. Lack of medical attention and good nursing.

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Variation and Evolution.

No branch of the study of natural history is more interesting, or more likely to lead to valuable results, than that of the causes of the large amount of variation which is exhibited by many species of animals.

If, as seems certain, what were at first varieties, in the process of time, by increase of the differential characteristics, or simply by these becoming permanent, originated new species, we are, while studying the causes which favor these variations, at the same time gaining an insight into those of the origin of species themselves.

No class of animals offers more favorable conditions for this study than the terrestrial and fresh-water mollusca. The great variety of conditions under which many species live, and the numerous varieties into which they are divided, together with the ease with which they may be collected and kept under observation, make them peculiarly suitable for our purpose.

Darwin says in an extract from one of his letters which I have lately seen: "In my opinion, the greatest error I have committed has been in not allowing sufficient weight to the direct action of environment, independently of natural selection." Probably those changes which are commenced in a species by the influence of environment are, in process of time, fixed by means of natural

selection. That there is a preference exhibited for individuals of a like variety, even where the variation cannot be supposed to confer any benefit, may be proved by anyone who will observe the pairing of that most variable species, both in color and banding, Helix nemoralis, be will find, though with many exceptions, that among the pairs which he may discover by the roadside, soon after sunrise or in the evenings during spring and early summer, that there is a decided preference shown by these animals for individuals similar to themselves, the red varieties prefer to mate with those of their own color, as do the yellows; while, in a less degree, it will be found that the many-banded select mates among their own class rather than from the one-banded or unicolorous forms.

That in the majority of instances, at least, the progeny in those cases in which individuals of a similar variety have mated resemble the parents I have been enabled to prove by selective breeding. I am still continuing these experiments, and hope to have something further to say on the subject at a future time. Doubtless other species show preferences of this kind. I have referred, however, to those of which I have most experience. Is it not probable that Helix hortensis and H. nemoralis have been derived from a common form in comparatively recent times through varietal differences which have at last become specific?

Malacologists in America have opportunities denied to us in the old country. They have the great advantage of being able to study the variations, in introduced species, which have been produced as the consequences of that introduction.

As species introduced into a new country, under different climatic conditions to those under which they have previously lived, are in some degree similarly circumstanced to species living through climatic changes produced by alterations of land and water surfaces. etc., during the changes which all parts of the world have undergone during the long geological ages, we have in their cases a means of studying what changes certain conditions are able to produce, and consequently of gaining an insight into the causes which have helped to the development of our present fauna from their remote ancestors of the past. We can study the effects of a more equable climate in some parts, of greater heat or cold in others, of more and less moisture, of changes in the food-plants, of exposure to the attacks of new enemies, etc

The more this subject is investigated, the more, I believe, will become apparent the fact that all species possess latent powers which the proper stimulus in the shape of altered circumstances, such as those suggested, is capable of bringing into action for the benefit of themselves and their descendants.

The observations at present recorded relating to the causes of variation are scattered through a large number of publications, these, in a short series of articles for another journal, I have endeavored to bring together and arrange for reference. Some of the causes which the various writers have assigned as probably inducing variation may be mentioned. Deficiency of lime in the soil produces thin, horny shells, and in some degree may cause change in their shape. Moisture, when deficient, is supposed to favor the formation of thick, white shells among the terrestrial mollusca, while its extreme abundance prevents the formation of colored bands in those species usually possessing them. Deficiency of light (as in dense forests) has been referred to as the cause of dull, unicolorous shells, while those more exposed to its influence are often gaily colored. Heat, combined with moisture, is considered conducive to brilliant coloring, with dryness as increasing the influence of the latter, while among the fresh-water species it tends to the production of fragile, dwarfed shells, overcrowding among the latter having a nearly similar effect. Dense vegetation, impeding the progress of aquatic species, has been considered a cause of scalariform varieties. Flowing and stagnant water are well known to effect the Limnacidæ to a large extent. Muddy, rocky, and sandy bottoms also have their effects. Food is undoubtedly an element of great importance in the manufacture of varieties in its relative abundance and luxuriance, while other circumstances have been observed where certain plants existed in unusual abundance. The presence of certain molluscan enemies has been found coincident with peculiar deformities, e. g., that of Hydra viridis, with deformed examples of a species of

Limnæa. Again, Mr. W. Doherty, writing from Cincinnati, records a remarkable dentate variety of Conulus fulvus; he further remarks that dentate species of Helix are the forms there prevalent, and points out that this formation is useful in obstructing the entrance of a grub which lives in beds of leaves and preys on small snails.

An American malacologist, Professor Wetherby, adduces evicence which goes far to prove that even malformations resulting from individual injuries may, under certain circumstances, be transmitted to the offspring.

In investigating these phenomena and their causes, I would suggest, first, that the manner of variation should be investigated and described, and, second, the exact nature of the surroundings as regards possible causes, always bearing in mind the conditions under which the species lives in its original home, and especially noting all deviations from these which may be supposed to induce the varietal character.

Among the species common to North America and Britain are the following: Vertigo alpestris, V. edentula, Conulus fulvus, Helix aspersa, H. hortensis Limnæa peregra, L. auricularia, L. stagnalis, L. palustris, L. truncatula, Physa fontinalis, Bullinus hypnorum, Planorbis albus (= P. hirsutus, Gould), P. glaber (= P. parvus, Say). W. A. GAIN.

Tuxford, Newark, England.

Books for Children.

IN answer to Mr. Waldo's request printed under the above heading in your issue of Science for June 16, let me suggest that such books as he desires are a desideratum not only for children, but for adults who, while not scientifically inclined, ate yet interested in the wonders and beauties of nature. Unfortunately our attention has been too exclusively absorbed with the struggles and the problems incident to a new country for us to have time to educate the men who could study and name all our plants and animals, much less those who could translate scientific monographs into popular language. Especially in the insect world a good collector could bring in from any summer-day's excursion dozens of specimens which have never yet been christened.

But while we cannot hope for books which will enable us to attach names to everything we may find in a ramble through Nature's museum, most of the more conspicuous animals and plants have been studied, at least enough for this purpose, though the results have been put forth in scientific works. But on the stores of knowledge thus accumulated popular writers are beginning to draw to meet the demand created by our growing outof-door life, our increased out-of-door interests. As was to be expected, plants have received the greater amount of attention. Mrs. William Starr Dana's "How to Know the Wild Flowers," just published by Charles Scribner's Sons, at $1.50, is intended to teach one to identify the commoner flowers by color, size and shape of leaf, size of plant and so forth. Ten-year-old children would seem to me rather young to use such a book, but it is admirable for those of twelve or thirteen. Newhall's Trees of Northeastern United States," published by G. P. Patnam's Sons, at $2, teaches one to identify trees by the leaves, bark, and so forth. This I know from experience to be admirable for children. The same author is at work on a similar book upon shrubs, but I believe it is not yet out. I know of no such book on birds as the ones I have just suggested on plants. The best thing for children I believe to be Florence Merriam's "Birds through an Opera Glass," published by Houghton, Mifflin & Co., at 75 cents. The appendix to this little book contains lists giving form, color, size, habits, song, flight, nest, and so forth of our common birds. A fuller and altogether admirable book on birds is Minot's "Song and Game Birds of New England," published, I believe, by Casino, at $2.50 or $3. The best book on insects is one which Professor Comstock, of Cornell University, has in band. It will probably be out now in the course of a very few months. Prepared especially for the school children of California, it is written in a manner attractive to children and will contain tables by which any insect may be traced to its proper fam

ily. Farther than this it would be hardly possible for a child to go, as the characteristics on which genera and species are founded are often so difficult of observation that the best tables which could be prepared would be only a source of perplexity and

worry.

After all the best method of teaching children is that which Mr. Waldo quotes as employed by his former teacher. And there are many books which occur at once to the mind of any teacher as valuable aids to the parent who wishes to work with his child. I have not named these because I understood the request to be for books which the child could use alone. But I should be happy at some future time to extend my list if it is not done by some other person better qualified for the task. M. A. WILLCOX,

Professor of Zoology, Wellesley College.

Two Queries.

AN incident of a recent personal experience may interest those of your readers who are studying the subject of mimicry. On the 21st of May last, I was botanizing with two companions in the thinly populated sand-dune region at the south end of Lake Michigan, and about forty miles east of Chicago, when the event I am about to relate occurred. I was walking rather in advance of my companions across a level area that separated two series of high dunes, when I accidently stepped upon two large snakes which were lying close together, doubtless enjoying the warm sunshine. It was a case of mutual surprise, and as the snakes, or one of them, suddenly sprang upward into unpleasant proximity to my face, I only a little less suddenly sprang backward, believing for the instant that I had encountered a rattlesnake. I soon discovered, or thought I did, that the reptiles were only fine specimens of the kind of black snake, popularly called the blue racer. One of the two had been considerably hurt by my heavy tread, and with violent contortions of his body made what haste he could to a hole about six feet distant, and disappeared in it. The other was uninjured and crawled rather leisurely away in another direction to a distance of twenty feet or more, and then lay quiet, watching our movements. Irritated by the violent start I had received, and cherishing no great love for snakes in general, I seized a club, and, while his snakeship lay broadside to me, I aimed a vigorous blow at him. I was again surprised, even more so than before, though in a different way, for with lightning rapidity the lithe reptile dodged the blow which otherwise would have struck him near the middle of the body, and instantly threw himself into a coil precisely resembling that of a rattlesnake when about to strike, and shook his erected tail with such vigor and rapidity that it was scarcely more distinctly visible than the spokes of a bicycle wheel when propelled by a fast rider. At the same time a sound was emitted, less shrill perhaps, but continuous and distinctly similar to that produced by the rattlesnake. Whether the sound was produced by the very rapid vibration of the tail, assisted perhaps by its scaly covering, or whether it was a hiss produced in the ordinary manner, I am of course unable to say. So close was the mimicry that I was for the moment almost deceived into the belief that I had mistaken a rattlesnake for a racer. The illusion was soon dispelled however, for a stick which I threw at him hit him on the head and stunned him, and I then had the opportunity to scrutinize him closely and verify my first conclusion.

I have frequently heard of other constrictor snakes mimicking venomous ones, in fact have occasionally observed such mimicry myself, but never before in this species and never in such perfection. It would be interesting to know if others have observed the habit in this species.

On the same trip another fact of interest came under our observation. The region visited contains many ponds and lagoons, and in these turtles (mainly Chrysemys picta, Ag. and Nanemys guttutus, Ag.) abound. About these ponds, often many rods from the water, were the remains of hundreds of turtles that bad evidently all been killed since the opening of the spring, and some of them within a few hours. The dead turtles varied in size from those with carapaces two inches long to these fully six inches in

length. It was clear from an inspection of those most recently killed, that they had been killed by some animal for food. The flesh of all had at least been partly devoured, but it was observed that not a carapace nor a plastron was broken. The reptiles had been killed, apparently, by some sharp-beaked bird, by thrusting its beak between the joints of the reptile's armor, so to speak. The loon is clearly competent to do this, but lcons are seldom seen in this locality. Moreover these birds would hardly drag their prey so far inland to devour it, as was observed to be the case with many of the turtles. The blue heron is more abundant here than the loon, but still not abundant enough to be credited with so much destructive work on animals so large. I have never suspected him, either, of being a turtle-eater. The only other birds competent to do the work and sufficiently numerous and intelligent to be suspected, are crows. Several flocks of these were hovering about the locality, and though we were not able to approach the wary birds close enough to observe them feeding, our suspicions fell upon them. Has any reader of Science observed crows killing turtles ? If so, is this a well established babit of the bird or is it one which has been recently acquired?

Chicago, Ill., 2421 Dearborn Street, June 14.

The Aurora.

EDSON S. BASTIN.

DR. VEEDER'S reply of June 2nd, is so objectionable on account of the positive way in which he closes his part of the argument (believing, as I do, that his facts are in fault) leaving it to be believed that at "no point throughout the research has there appeared to be even the slightest chance' for an alternative hypothesis," that I am once more tempted to reply. Let me, before passing on, emphasize the fact that we are not discussing the question of "magnetic storms" and sun-spots. I believe there is only one astronomer and physicist of any eminence who disbelieves in this association, so that as far as discussion of the question is concerned, we may consider it as practically closed; but, even if I held the contrary opinion with the majority, so long as an opponent of such eminence held out, I should consider it inadvisable to be as positive as Dr. Veeder in his last letter, on the subject of the aurora, where, I believe, I am not alone in supposing there is reason to doubt a connection between this display and areas of disturbance on the eastern limb of the sun. I have raised some well-known objections to this theory, and, as a rule have been met by Dr. Veeder with generalities (Science, April 7, 28, May 19 and June 2); it is unnecessary to mention them again here, so that I shall content myself with dis cussing this last contribution, which leaves me in such an unccmfortable position, apparently.

66

The whole base and superstructure of this theory is erected upon a solar period of rotation of 274 days," and to quote from a letter which I have received from Dr. Veeder, dated March 16, 1892, the addition of "a few hours difference in the length of the period introduces a drift into the tables that becomes everywhere apparent" Surely this is a suspicious degree of perfection in the theory, as no one knows what the solar period of rotation is: such periods as have been determined from sun-spots (the only possible method so far) give values between 25 and 271 days, depending on the solar latitude of the spot; yet, the addition of a "few hours" can introduce a "drift which becomes everywhere apparent." when 2 days is left out of the tabulating without apparent effect, for, it is evident, that in considering the effects of the return to the eastern limb of a sun-spot or area of disturbance, that it is not a fixed rotational period that should be used, but the one belonging to the latitude of the spot under discussion.

This year auroras were visible here on the following days of the year: the 5th, 6th, 8th, 21st, 35th, 36th, 44th, 45th, 46th, 47th, 104th. 109th, 127th, 128th, 130th, 144th, 145th, 160th, 164th, 165th and 166th. If auroras are caused by a disturbed solar area at the eastern limb, we should find, by adding the interval adopted by Dr. Veeder of 27 days to any of the above days, the probable date of the returning display. What do we find in fact? That, of the 52 periods obtained by adding this interval in succes

sion to the above days, up to the present date, there were only 10 of the days so determined on which displays took place; that is, 20 per cent of successes as against 80 per cent of failures. In illustration of the above, the aurora of the 5th day should have reappeared on the 321, 59, 86. 114 and 141; from the days of auroras given above, it will be seen it appeared on none of the required dates; nor did that of the 6th; that of the 8th reappeared twice out of five solar periods; the 21st, once out of five; the 35th, once out of four, and so on.

One more objection, previously overlooked, before passing on. I am of opinion (no one can be certain, failing the necessary observations), that there is practically no instance in which aurora displays are not taking place in one hemisphere or other of the earth; a large proportion should be observed co-incident with any other class of recurrent phenomena, and think it possible that "chance," which Dr. Veeder avoids the discussion of, is really an important element in our discussion, as I shall now endeavor to prove this by his own admissions.

"The year

In a letter to me, dated May 4, 1892, he says: 1879, selected for printing as an illustration of the results seen throughout the entire table, is one of profound minimum at which times solar disturbances are well separated from each other and the relation comes out distinctly although for the construction of such a table one year is just as good as another." (italics are mine.) This is a perfectly sound conclusion, and by it alone might this theory stan or fall if chance" is not, or is, as important as I maintain. On May 13th. Dr. Veeder writes: (This table of comparison between the phenomena being now printed) "It [1879] being a year of minimum the relation does not come out so strongly as when disturbances were more numerous. In the next year (1880) the numbers would be much larger and the relation in every way more distinct.

Scientific Words in the Century Dictionary. ALTHOUGH one of the most useful books published, the Century Dictionary is, of course, not faultless. The mention of a mistake in a recent issue of The Critic reminded me also of the following:

According to the latest edition of Foster's "Physiology," saliva "in a healthy subject is alkaline, especially when the secretion is abundant. When the saliva is scanty, or when the subject suffers from dyspepsia, the reaction of the mouth may be acid." According to the Century Dictionary, the saliva is a colorless ropy liquid which normally has an acid reaction."

The word "griffe," which is commonly used in Louisiana, is defined by the Century Dictionary as a "a mulatto-especially a mulatto woman." I have copied in a note-book from a lecture delivered in New Orleans by Hon. Charles Gagarré, the historian of Louisiana and authority on such matters, the following:

In Creole America there is a very mixed population Even in very early times there were these distinctions: European, or fresh white immigrant; Creole, or pure white American of European parentage; the aboriginal Indian; the griffe, or cross between Indian and negro; the mestizo, or mixed white and Indian; the mulatto, etc., etc." These may not be the exact words of the speaker, since I may have misunderstood or copied it wrongly, but I think the same statement may be found in one of his works. Griffe, no doubt, is from the Spanish grifos, meaning frizzled