the other. Otherwise he will not be able to compete with the white race in the economic struggle for land or the political struggle for power."

This is a sad conclusion, but it is that which is supported by the history of both the Red and the Black races, and is that which is illustrated by the histories of so many of the Polynesian islands, where the circumstances were most favorable to the development of the best relations between the natives and the Europeans. The psychic traits of races are as unalterable as the shade of their hair, and inevitably for them define the future of their stock and limit its possibilities.

The Land Fu-Sang.

Now that the discussion of the various discoveries of America is in order, that which is referred to in Chinese annals as far back as the seventh century, in connection with the name Fu-Sang. should receive attention. It was first brought to the notice of scholars in 1761 by the French orientalist, De Guignes, and of course created some sensation. Various writers since then have warmly espoused his views, among whom may be mentioned in our own country Charles G. Leland and E. P. Vining, both of whom have issued volumes in proof of De Guignes's identification.

The coup de grace seems to have been dealt the theory by Gustave Schlegel in his book published in Leyden this year entitled "Fou-Sang Kouo; le Pays de Fou-Sang." He is a Chinese scholar of acknowledged competence, and takes up the story as recited in the original, with as many side-lights as he can bring to bear upon it.

The result of his researches is to knock every pin from under the notion that any part of America could have been intended in the description of Fu-Sang. As far as any real land can be discerned through the fog of exaggeration and fable which encircles the whole account, it is that of the island Krafto or Saghalien, and the people described resembled the Ainos more than any others. A variety of arguments are adduced to show that Mexico is out of all question; and therefore those fanciful archæologists who have been ready to find Buddhistic elements in American religions will have to look for them elsewhere than in the legend of Fu-Sang.

Another Failure in Ethnic Osteology.

The trenchant criticisms of Professor Sergi of Rome have already been referred to in these notes. He has recently published another of these in which he attacks and apparently demolishes the favorite theories of Professor Kollmann of Basel, in relation to the analogy existing between the face and its members. The latter has long maintained that there is a constant correlation between the elements of the face of such a nature that to long faces correspond high orbits, narrow nasal apertures, and elongated palatine vaults; and to wide faces the converse of these characters; and that the types of races expressed in headforms will be a composite of the cephalic and facial indices.

Professor Sergi arrives at quite a different conclusion. He points out from various series of skulls that in the purest types the craniological criteria vary very widely. In every race individual examples present the utmost diversity. As to any fixed correlation between the shape of the face and the facial indices, which is the crux of Kollmann's argument, it is a pure chimera. He presents a series of measurements, tabulated from African and American crania, which leave no doubt as to the accuracy of his assertions; and Dr. Colignon, who reviews his work for L'Anthropologie, accepts its conclusions as incontrovertible. This is another serious blow to that department of physical anthropology which has set up a few anotomical features as more important than those of language and mind, as criteria of peoples.

WE are informed that in view of the general interest awakened in the cholera, Dr. Klein's well-known little book on "The Bacteria in Asiatic Cholera," published by Macmillan, has been reduced in price to one dollar. Dr. Klein is lecturer at St. Bartholomew's Hospital, London.

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.

On request in advance, one hundred copies of the number containing his communication will be furnished free to any correspondent.

The editor will be glad to publish any queries consonant with the character of the journal.

A Pre-Aino Race in Japan.

IN the Report of the National Museum for 1890, just issued, are two papers by Romyn Hitchcock, entitled respectively, "The Ancient Pit-Dwellers of Yezo" and The Ainos of Yezo, Japan." In these papers he advances the idea, which he evidently thinks is new, that there was a race of people in Japan previous to the Ainos, and these people he identifies with the Pit-Dwellers of Yezo. He says, "it has been supposed that the shell-mounds were left by the Ainos. This is the opinion of Professor John Milne." Mr. Hitchcock further says, "It has recently been shown by the researches of Milne, Morse, Chamberlain, and others that Japan proper was once inhabited by a race of people different from the present Japanese, and from the comparison of the remains found in shell-heaps and kitchen-middens in many parts of Japan, even as far south as Kiushiu, with similar remains found in Yezo, it is thought that the Ainos once inhabited Japan." It is hardly necessary to inform Mr. Hitchcock that the writers above mentioned did not require the evidences of shell-heaps to convince them that the Ainos inhabited Japan, as historical records in that country fully establish the fact. I have always maintained, however, and in one case with an acrimony which I now regret, that all the evidences point to the existence of a race occupying Japan previous to the Ainos, citing these very shellheaps as proof. I am not concerned with the fact that he has overlooked my views published at different times on the subject, but I do object most emphatically to being represented by Mr. Hitchcock as holding views directly the reverse of what I have repeatedly urged; and as the point of a Pre-Aino race in Japan, if established, is of some value, I do not intend to relinquish it unless other claims to priority can be shown. While Mr. Hitchcock has not taken the trouble to look up my papers on the subject, he cannot plead ignorance of my views, as he has made most ample use of a memoir by Mr. Basil Hall Chamberlain, published by the University of Tokio, and should have seen the following statements in that publication (p. 44). Mr. Chamberlain says: "Two theories may be held with regard to the former pres ence of the Ainos in Japan. One is that they have occupied the whole country before the arrival of the Japanese. This theory has been advocated by Professor Milne. . . . The arguments used by Professor Milne are chiefly derived from archæological finds. ... To his arguments, which should be consulted at some length, ... it has been objected by Professor Morse . . . that there is no positive proof that the remains attributed by him to the Ainos may not have been left by some still older race." There is, therefore, no excuse for this oversight or blunder on the part of Mr. Hitchcock.

Fifteen years ago I sent from Japan a communication to Nature of London, entitled "Traces of Early Man in Japan." In this I said: "The examination of a genuine kjoekkenmoedding, or shell-heap, enables me to give positive evidences regarding a prehistoric race who occupied this island." And when I designated this race as pre-historic, I supposed every one familiar with Japanese history was aware of the fact that the Ainos had preceded the Japanese in Japan, as the Indians had preceded the English in New England. Hardly a popular book on Japan had failed to allude to the fact, quoting early records of the Japanese in proof of it. Over thirteen years ago I sent an article from Japan to the Popular Science Monthly, entitled "Traces of an Early Race in Japan." This was published in the January number, 1879, and contained numerous engravings. In this paper I said: "With every reason for believing that the Japanese came from the south, displacing the Ainos, who came from the north, the question next arises as to the original occupants of the island. Did the northern people encounter resistance from a primitive race of savages, or were they greeted only by the chattering of relatives still more remote, whose descendants yet clamber about

the forest-trees to-day? The records are silent upon these points. A discovery that I made in the vicinity of Tokio last year leads me to believe that possibly the traces of a race of men previous to the Aino occupation have been found." Again I say: "The next question arises as to whether the deposits are Aino or pre-Aino. The race who left these remains were pot-makers par excellence. It is generally admitted by ethnologists that the art of pottery once gained is never lost. It is a fact, however, that neither the Esquimaux, Aleutians, Kamtchadales, nor the Ainos are essentialy earthen pot makers." And, again, having shown incontestible proofs of the evidences of cannibalism in these deposits, I ask, "Were the Ainos cannibals? Repeated inquiries among eminent Japanese scholars and archæologists, like Mr. Kanda, Mr. Ninagawa, and others, as to this question, are always answered in the same way. Not only were they not cannibals, but they are reported as being so mild and gentle that murder was never known to have occurred. So monstrous a habit would certainly have been known and recorded, particularly in the painstaking annals of early historians."

In the Proceedings of the American Association for the Advancement of Science for 1878 occurs in the list of papers read by title the following one of mine, entitled "Evidences of Cannibalism in a Nation before the Ainos in Japan." A foot note states that this paper was published in the Tokio Times

In the year 1879 the University of Tokio published my memoir on the Shell Mounds of Omori," illustrating the various forms of pottery, bone implements, etc., by seventeen folded plates. While this memoir is devoted exclusively to a minute description of the Omori deposits as a basis of comparison with material that I had on hand for the description of other shell-heaps, yet I urged the evidence of the deposits not having been made by Ainos, but by a race anterior to the Ainos, and cited especially the evidences of cannibalism as bearing on this point.

Twelve years ago I had occasion to criticise and controvert (American Naturalist, September, 1880), in the most emphatic manner Professor Milne's views as published in the Transactions of the Asiatic Society of Japan. At the same time I also showed, as I believed, the fallacy of the views of Henry von Siebold on this question. Thus in various publications in 1877, 1878, 1879, and 1880 I have urged the existence of a pre-Aino race in Japan.

Had Mr. Hitchcock taken the trouble to give proper credit to others who had worked in this field, he would have found additional support to the position he takes; as it is, his paper is marred by misapprehension and by the injustice of these omissions. EDWARD S. MORSE.

Salem, Mass., Aug. 30.

On the Fundamental Hypotheses of Abstract Dynamics; From Another Point of View.

THERE is at present very little agreement among physicists or philosophers as to the nature of the hypotheses or laws upon which dynamics is based. On Aug. 5 Professor MacGregor expounded one view of the matter in these columns; but as I cannot but think his view contains some logical imperfections, I wish to lay before your readers a different view with which to compare it. For this is not a question to be settled by authority; the arguments on either side are after all simple enough, and, having studied them, any man of average attainments is capable of weighing them and forming his own opinion.

The principles of abstract (subjective) geometry may be deduced from definitions of the terms "Position" and "Direction," together with certain axioms asserting the conceivability of geometrical figures and constructions. Even without these axioms a symbolic geometry might be deduced, whose conclusions, however, would be mere truisms, or verbal assertions, till they were given a meaning by the axioms. To proceed to the objective geometry of material space, we require in addition certain inductions; which, however, are so complete that no practical doubt remains as to their validity.

See my "Foundations of Geometry," Deighton, Bell, & Co., Cambridge, Eng., 1891.

In the same way we may treat kinematics from three different points of view. Symbolically, it is sufficient to define Time implicitly by the assertion, The positions of points are all continuous single-valued functions of the Titne." This definition may be given a subjective meaning by the axiom, "Particles are conceivable in Time,” and an objective meaning by an induction proving that "material particles exist only in Time." i.e., their positions are continuous single-valued functions of a certain variable, which we may call Time.

To proceed to kinetics symbolically, we require definitions of Mass and Force. The only connotation symbolically required for the former term is "Mass is not a function of Space or Time.” The latter term may be defined implicitly by assertions equivalent to Newton's laws of motion, which may be stated thus: —

1. The resultant force on any particle in any direction, referred to a given set of axes, is the product of the measures of its mass and its acceleration in that direction.

2. All forces go in pairs between pairs of particles, equal forces in opposite directions acting on the particles respectively in the line joining them. (Such a pair of forces may be spoken of as a stress.)

It is evident from 1, since mass is not a function of space or time, that forces, like accelerations, are vectors, and may be compounded by the parallelogramic law. Paragraph 1, however, only speaks of resultant forces, and the actual, or acting, forces on any particle would remain entirely arbitrary but for paragraph 2, which must be read in conjunction with 1. Professor MacGregor asserts that paragraph 2 is not consistent (i.e., might be inconsistent) with 1. So far from this being the case, I propose to show that it still leaves the term Force to some extent arbitrary. The stresses between particles are not completely determined, even with reference to a given set of axes; and, moreover, both Force and Stress are relative to the axes chosen.

In geometry and kinematics both position and direction are relative terms. To determine a position we require to know its distance and direction from a given position. To know its direction we require to know the inclination of that direction to two given (independent) directions, and, in addition, which side it is of the plane determined by them.

Suppose, then, we have a set of particles numbered from 1 to n. Choose the first particle as origin of a system of rectangular coordinates; the direction 12 as that of the axis of x; the direction at right-angles to this in the plane 123, and on that side of the line 12 on which the particle 3 lies, as that of the axis y; and the direction perpendicular to the plane 123, on that side of it on which the particle 4 lies, as that of the axis z. Thus we have determined a set of axes completely, and in doing so we have made the six arbitrary assumptions:

and two similar equations with y and z (r1, being the distance between the particles). Thus in all we have 3 n equations ben-n-1 tween quantities F12, F13, etc. But these equations 2 may not all be independent. As, however, they contain (3 n 6) independent variables, x2, x, y, etc. (the other six having been arbitrarily equated to zero), there will in general be (3 n − 6) of them independent. If they only just sufficed to determine the quantities F12, F13, etc., we should have

hence the two assertions about Force are arbitrary and may be laid down as a (partial) definition of that term.

From this definition all the theorems of dynamics may be deduced, as from Newton's laws of motion. The theorems of statics may also be deduced, the only difficulty being the principle of virtual work. This difficulty, however, disappears as soon as the term "geometrical conditions" is properly defined.

We have then a symbolic dynamics. To give it a subjective meaning we have to conceive a real denotation for its terms. It is not, however, necessary to give a real denotation to Force if we can do so to Mass, for we may still regard Force as merely a name for the product of mass by acceleration, or (which is the same thing) as the time-flux of momentum. To give the theory an objective application it is necessary to show that what we call material particles not only occupy positions which are continuous one-valued functions of what we call Time, but also possess a certain characteristic which is not a function of space or time, and which may be called Mass. Then, whether we attach any denotative meaning to Force or not, we can discuss the forces or stresses that must be postulated between various particles of matter. The magnitudes of these will in general depend on the axes we assume by which to determine positions, and also on the masses assigned to the various particles. The axes and masses are therefore assumed in such a way as to make the resulting system of stresses the simplest possible. For example, it is generally assumed that the stress between any two particles diminishes as the distance between them increases, and may be neglected if this distance is very great. Hence in astronomy the attractions of the fixed stars on the planets may generally be neglected, and we may discuss the solar system alone. It is further shown that the system of stresses between the sun and planets is simplest when a certain plane is taken as "the invariable plane." But we do not really know that the stresses thus deduced are the actual ones, or indeed that there is any actual phenomenon corresponding to what we call stress at all. Any plane might be chosen as the "invariable" one, at the cost of having to postulate a more complicated system of stresses. We cannot determine fixed directions dynamically, any more than kinematically, except by making assumptions which are really arbitrary about the stresses between certain particles.

As Professor MacGregor points out, the law of the conservation of mechanical energy would flow from the assumption that stresses are functions of the distances between the particles on which they act. But this would not include the general law of conservation of energy until all energy was shown to be mechanical energy. And even then, on the above assumption, the term conservation of energy would be rather misleading; for the kinetic energy is not conserved unless the term potential energy is merely used as a cloak to hide our ignorance of kinetic energies which for the moment have passed beyond our ken. For example, a few years ago it might have been said that when we project a keeper away from an electro-magnet, the kinetic energy with which it starts becomes converted into potential by the time it stops, just as when we throw a stone into the air. But if, while the keeper is at a distance from the magnet, the current is switched off, that potential energy is abolished! The true view is, however, that there never was any potential energy at all, the energy of the flying keeper had its equivalent in an increase in the electric current round the magnet a kinetic, not a potential, energy. And I have no doubt that some day science will show a similar explanation to hold with respect to gravitation and other actions at a distance. When that day comes the term "potential energy" may be banished to "the limbo of once useful things."

It will be seen, therefore, that I differ from Professor MacGregor chiefly in denying "the non-relative character of Force." Professor MacGregor says, "it is easy to show that if it [the third law of motion] hold for one point of reference, it cannot hold for another having an acceleration relative to the first." I should like to see his proof; but if he refers accelerations to a single point, I can well understand that he should arrive at results inconsistent with mine. For, as I have shown, the apparently absolute determinations of direction depend in reality on arbitrary assumptions as to stresses. Having made these arbitrary assumptions, it may

well be impossible to further make arbitrarily the assumptions involved in the third law of motion.

I cannot quite follow his paragraph beginning "It may easily be proved that the stress between two particles is proportional to the product, by the sum of their masses into their relative acceleration." There seems to be some misprint; but how a single particle could in any case exert all the forces acting on a system of particles, I cannot understand, unless the words "equal and opposite" in the third law of motion are not held to imply that the forces act in the line joining the particles, which, moreover, is distinctly implied in the Professor's law of stress. In any case the difficulty referred to above comes in again, viz., that we cannot determine directions absolutely, or positions by reference to a single point.

In conclusion, I should like to point out that it seems inconvenient, even if Professor MacGregor's views be accepted on other points, to include in one law of stress, two statements resting on such very different evidence as that forces may be considered to be attractions or repulsions, and that their magnitudes depend solely on the distances between the particles on which they act. It would give a student a very false notion of the fundamental bypotheses of dynamics to teach him that he must accept or reject both these assertions together. EDWARD T. DIXON. Cambridge, Eng., Aug. 20.

The Fundamental Hypothesis of Abstract Dynamics. PROFESSOR HOSKINS points out (Science, Aug. 26, p. 122) that for the conservation of energy the necessary and sufficient condition is that Σ Pdr shall be a perfect differential of a function of the quantities r, P being the stress between any two particles of the system, and r their distance; and that the condition that each P shall be a function of the corresponding r only, which I suggested for adoption as a fourth law of motion, with a view to the deduction of the law of the conservation of energy (Science, Aug. 5, p. 74), while sufficient, is not necessary.

There are three reasons which influence me in selecting for the fourth law an hypothesis which is more than sufficient for the main purpose in making the selection, viz., (1) that it is capable of simple physical expression, (2) that it is already known to hold in the case of several natural forces, and (3) that the additional assumption involved in it, over and above that necessary for the deduction of the conservation of energy, is one which is, I think, invariably made in investigations on the laws of natural forces.

What the additional assumption is, is readily seen. In a system of two particles A and B, Σ Pdr becomes Pdr; and in this case it is both necessary and sufficient for the conservation of energy that the single stress acting shall be a function of the distance AB only. If we add a third particle, C, to the system, conservation no longer requires that the stress between A and B shall be a function of the distance AB only, though it is secured if that condition is fulfilled. Thus the proposed law assumes, in addition to what is required for conservation, that the stress between A and B is not changed by the fact that other stresses have begun to act between A and C and between B and C. The proposed law therefore involves an assumption similar to that implied in Newton's second law. As Newton's law assumes that a force produces the same acceleration in a particle whether other forces act on it or not, so the proposed law assumes that the stress between two particles is the same whether or not there are other stresses acting between them and other particles.

That this additional assumption holds in the case of some natural forces has been abundantly verified, and in investigations into the laws of forces not yet determined, so far as my knowledge of such investigations goes, the same assumption is always made. This being so, we would seem to be warranted in adopting, tentatively of course, as a fourth law of motion an hypothesis in which this assumption is implied. The proposed law cannot be said to have received anything like the verification that Newton's laws have received. But of the many deductions which have been made from it, none have been contradicted, while many have been corroborated, by experience. J. G. MACGREGOR.

Shubenacadie, N.S., Sept. 2.

The Nomenclature Question.

I AM glad to see this question brought up as it is by Professor Underwood in the number of Science for Aug. 26; for we should have a uniform nomenclature in all departments of natural history. That such is not the case now is apparent to every student who is working in any of its various branches. But I do not wish to discuss the subject in general, but to touch upon one or two points. As to the question of priority, there should be some definite rules by which this should be governed, as has already been said in other of our scientific periodicals, and it will not profit by any rehashing it here, further than to say that among entomologists it is generally understood that the mere proposal of a name for a genus without characterizing it does not hold against a later name accompanied by a description.

As to the act of a writer who takes a species already named and puts it into a new genus with his own name after it instead of the name of the original describer, that is an outrage that has not been tolerated among entomologists for some time. I can see no valid reason for retaining such a system of nomenclature in any department of natural history, merely that some reviser may gain a little cheap notoriety.

A word as to the initial letter of specific names. It seems to me that the name of a species is a proper name as much as the name of a genus; in other words, it is the name of a group of plants or animals, and, if such, is as much entitled to a capital

initial as is the name of the genus. Many of our leading entomologists have adopted this view and begin all specific names with capitals; as, for instance, see Edwards's "Revised Catalogue of the Diurnal Lepidoptera of North America," 1884; Kirby's "Catalogue of Diurnal Lepidoptera," 1871 and 1877, etc. I believe it is the correct principle and follow it in all my work in natural history. G. H. FRENCH.

Southern Illinois Normal, Aug. 30.

The Grand-Gulf Formation.

THIS has now become a clearly recognized division of the posteocene geology of the Gulf States. No subdivisions of it have as yet been attempted in print, though more than three years have elapsed since the writer - then in the service of the U. S. Geological Survey - announced the first discovery of fossils on Pascagoula River and the two branches which form it, Leaf River and the Chickasawhay, near their junction. The exact locality of the largest deposit is Shell Bluff, just below Robert's Ferry and a few miles south-west of the post-office Vernal, in Greene County, Mississippi. It was then proposed to call it the Pascagoula formation, and to regard it as distinct from Dr. Hilgard's GrandGulf. Further developments and recent discoveries have confirmed me in this view. It was not at first accepted, because there is but the one witness, myself, and attempts to trace it westward and eastward failed to detect the same or similar fossiliferous beds on the Mississippi, on Pearl River, on the Alabama River, or on any of the smaller streams of these States. This kind of negative testimony would only go to restrict its extension, and not to overthrow the validity of the distinction if otherwise properly established.

Many facts, too numerous to be elaborated in this short paper, prove that the great Mississippi embayment had collateral branches in which the variations are too well defined to be disregarded. The Pascagoula embayment was one. And whilst the main body of the Grand-Gulf formation is of sand, sandy clays, and quartzites due to a fresh-water agency, in the Pascagoula formation it presents a marine aspect, where calcareous clays, more or less pure and with more or less distinct evidence of molluscan fossils, prevail. The boundaries of these two will not be attempted in this paper. Let us pass at once to some of the strongest and more recent proofs.

Of the shells discovered at Shell Bluff it may be said only one, the large oyster, could be clearly determined. The rest were in a condition so decayed and friable as to render their transportation in good condition impossible. But as I remember them, the oyster approached, yet differed from, the recent O. Virginiana, among other particulars, in its greater massiveness. Among the other

shells too rotten to be moved was one strongly similar to a Gnathodon, though it may turn out to be a Mactra. Another, and the most numerous, was a small shell somewhat resembling in size and outline the Donax so common on our beaches, but with less umbonal development, and with the distinctly visible lines of growth resembling Venus. The difficulty in this case as well as the other is that the hinge could not be clearly made out.

Borings for artesian wells at Biloxi and other places on the Mississippi coast, and quite recently at Mobile, Ala., solve the difficulty.

The Biloxi borings, among other things, brought up, from a depth in the neighborhood of 700 feet, fragments of a large oyster, which might well belong to that of Pascagoula, and a very easily recognized Gnathodon.

The boring at Mobile, from about the same depth and just above the water-bearing sands, has yielded similar bits of oyster, and a small shell, evidently the same as that of Pascagoula, and sufficiently preserved to be determined. It is a Venus, or very nearly allied to that genus, and if not already found elsewhere and named, the name V. Mobilensis is proposed for it.

Not having room to go further into detail, I wish clearly to say that I find evidence sufficient to establish the existence of a formation of deep-bedded gray clays of partially marine genesis, lying upon the water-bearing sands of the upper strata of the Grand-Gulf formation; that I have traced this clay from Pearl

River, Miss., to Conecuh River, Ala.; that it constitutes the

cover rendering artesian wells possible, and that it was for these clays that the name Pascagoula was proposed.

Meridian, Miss., Aug. 1.

LAURENCE C. JOHNSON.

European Origin of the Aryans.

My attention has been called to Dr. Brinton's note in Science for June 20 as to the claim of Omalius d'Halloy to have preceded Latham in calling in question the theory of the Asiatic origin of the Aryans. In 1890, when in his lectures on Races and Peoples," Dr. Brinton advanced the claim of d'Halloy, I carefully read over Halloy's articles, as cited by Dr. Brinton on p. 146 of his book, and I came to the conclusion that d'Halloy was not acquainted with the theory he is said to have controverted. The dates confirm this conclusion. The articles in question were published in the Bulletins of the Belgian Academy during the years 1839 to 1844, and were recapitulated in 1848. The theory of the migration of the Aryans from central Asia first found definite expression in an article by Pott, buried in a volume of Ersch and Grüber's Encyclopædia, which was published in 1840, but it attracted no attention till taken up by Lassen in 1847, and by Jacob Grimm in 1848. This was the theory against which Latham contended, whereas d'Halloy's very confused and misty arguments seem to refer, if they refer to anything, to the Caucasian theory broached by Blumenbach in 1781, with the modifications proposed by Adelung in his Mithridates, 1806-1816.

I think, therefore, we are still justified in asserting that Latham was the first to question the comparatively modern theory that the Aryan race originated in the highlands of central Asia, a theory of which d'Halloy does not seem to have heard, and consequently in the second edition of my "Origin of the Aryans," published in 1892, I did not think it necessary to modify my former statements as to Latham's priority. ISAAC TAYLOR. Settrington, York, England.

Acid Prevention of Cholera.

IN previous epidemics the value of sulphuric and sulphurous acids as preventives was demonstrated, and when Koch discovered his comma bacillus he also noted that its cultivation was possible only in alkaline media, and that acids destroyed it. In corroboration of these findings, Niemeyer, who wrote long before anything of this nature was known, records that the ileum, or lower small intestine, is the main seat of the pathological changes caused by cholera. This lower small intestine is the most alkaline and the farthest from the normally acid stomach. The large intestine, being acid, does not suffer.