fully double that obtained in the ordinary way. 2. The difficulties to be overcome in the application of diffusion are wholly mechanical. 3. The process of carbonatation for the purification of the juice is the only method which will give a limpid juice with a minimum of waste, and maximum of purity. 4. By a proper combination of diffusion and carbonatation, the experiments have demonstrated that fully 95 per cent of the sugars in the cane can be placed on the market either as dry sugar or molasses.

PROGRESS IN METALLURGY.

ONE of the serious metallurgical problems of today is the recovery of the by-products from the manufacture of coke by the destructive distillation of bituminous coal. In this country coke for metallurgical purposes is prepared almost exclusively either in open heaps or in 'beehive' ovens, hemispherical fire-brick chambers into which sufficient air is admitted to burn the distillates, and thus to produce the heat required for the distillation itself. Not only are the distillates, which contain ammonia and tar, of great value to the color-maker, thus wasted, but, as they burn in actual contact with the coking mass, much (often twenty-five per cent) of the coke itself is incidentally burned. Both these evils are completely avoided by coking in retort ovens, heated externally by the combustion of the distillates, but after they have deposited their tar and ammonia in surface condensers. The first volume of the Journal of the Iron and steel institute, for 1885, contains an important group of papers and discussions on this subject, whose net result is to place the advocates of retort coking in a much stronger position.

The iron blast-furnace is the chief consumer of coke; and though in continental European blastfurnaces (and in British foundery cupolas as well) retort coke is as efficient as beehive coke, and though the calorific powers of the two fuels are almost identical, yet in British and American blastfurnaces the efficiency of retort coke has hitherto proved so low as to largely offset the advantages of the retort, its greater yield of coke and its recovery of by-products. Hence the retort has gained but a slight foothold in these countries, though used on the continent very extensively and successfully with coals of widely varying compositions and properties. We may solve the retort problem either by adapting our retorts to the requirements of our coal, or by adapting our blast-furnaces to the requirements of retort coke.

Mr. J. Lowthian Bell shows by conclusive ex

periments that the low efficiency of British retort coke is due to its ready solubility in the carbonic acid which it encounters on entering the blastfurnace; and this, in turn, appears to be mainly due to the comparatively low temperature of retort coking. It would seem practicable, however, to raise this temperature approximately to that of the beehive; and Mr. H. Simon and Mr. Watson Smith describe the adaptation of the Siemens regenerative system to the retort for this purpose, and the improvement in the quality of the tar which it has effected. The problem of adapting the retort to the coal seems thus in a fair way to solution, while that of adapting the blastfurnace to retort coke appears to be in an equally promising condition, if we may judge from comparative tests which Samuelson describes, conducted on a gigantic scale in his blast-furnaces, themselves highly efficient, in which British retort coke shows an efficiency equal to that of the best beehive coke. This one success outweighs in importance fifty previous failures.

A very important contribution to the world's supply of tar and ammonia is promised from another source. A large and constantly increasing proportion of our metallurgical furnaces are heated by gas produced by the simultaneous distillation and partial combustion of bituminous coal and similar substances. In the apparatus employed the hydrocarbons, etc., arising from distillation, incidentally become diluted with such enormous volumes of nitrogen and carbonic oxide from the partial combustion of the coal, that the condensation of their tar and ammonia would require apparatus of a size and cost which are simply prohibitory; and, unable to separate these valuable substances, we burn them in enormous quantities. But Mr. John Head describes an egg of Columbus which promises to enable us to isolate the distillates for condensation and the manufacture of illuminating-gas.

A knowledge of the relations between the chemical composition and the physical properties of iron, which would enable us to infer the latter from the former, would be invaluable: unfortunately investigation has thus far only plunged these relations into hopeless confusion. To elucidate the subject, Dr. Hermann Wedding has carried out extensive and ingenious microscopic studies of the structure of iron. We have not space to analyze the results which he here presents, further than to give as a sample his announcement that malleable iron, produced by any fusion process, consists of two distinct components : 1°, minute porphyritically distributed crystalline particles; and, 2°, a homogeneous matrix in which they are distributed.

RECENT CHALLENGER MONOGRAPHS.

FOUR great books of final reports of the Challenger expedition, together with two volumes of 'the narrative,' represent the outcome of the last few months of work of the Challenger staff. Commendation seems superfluous in describing a work so monumental in its character; but, on the other hand, it is impracticable to speak of it, either as a whole or in any one of its subdivisions, without the most enthusiastic praise.

Professor Turner of Edinburgh discusses the human crania in a paper of 130 pages (part xxix. vol. x.), which is one of the most important contributions to somatology ever printed in English. The last sixteen pages are devoted to general conclusions, drawn, not only from the study of the crania gathered by the Challenger in southern Africa and America, Australia and the Pacific Islands, but of those in the Edinburgh university museum and several other collections. The paper is, in fact, an essay upon the craniology of certain races, the Bushmen, Fuegians and Patagonians, Australians, New Zealanders, and the Admiralty, Chatham, and Sandwich Islanders. A short paper, on the other human bones is to follow. The body of the memoir is densely packed with details of craniometry, for the most part in tabular form, and critical notices of past investigations. The 29 illustrations are exceedingly satisfactory, especially the diagrams of sections of skulls drawn by the author.

One of the most noteworthy results of this investigation is that it has given Professor Turner still stronger convictions upon the importance of craniology as the foundation of a classification of the races of mankind. Without undervaluing the classific value of such features as the color of the skin, the color and character of the hair and eyes, the shape of the nose and lips, the stature and the form of the pelvis, he maintains, that, by taking a combination of craniological characters, there may be laid down certain propositions as regards unmixed races of men, which, while allowing for the occurrence of occasional individual variations, will be as distinctive as those afforded by the study of any other series of physical characters.

In unmixed races, where the skull is markedly dolichocephalic, brachycephalic skulls never occur; and similarly in unmixed races, where the skull is markedly brachycephalic, dolichocephalic skulls are not met with. People resulting from mixtures, especially of dolicho- with brachy-cephalic races, are more difficult to deal with; for some will have heads which exhibit, with little variation, the characters of one or other of the two parent types,

while in others intermediate characters will arise which incline toward those of one or other of the ancestral types. It is, he thinks, through lack of recognition of the true effects of mixture of races that discredit has been thrown on the value of the skull in the determination of racial characters.

The author, while inclining to the belief that, as a rule, unmixed races are either long or short headed, and that mesaticephalic peoples usually proceed from mixtures, admits that certain of the mesaticephali for instance, the Tasmanians, and the Bush race of South Africa (not improbably the remains of the primitive people of Africa) — may be classed with the unmixed races.

The discussions of the extent and character of individual variation within the limits of a race are to be of a very scholarly and suggestive character.

The author advances the idea that the races of the extreme south, Bushmen, Fuegians, Australians, Tasmanians, and Negritos, with their feeble frames, small heads, low statures, and low intellectual development, may in the early unwritten periods of history have had in their respective continents a much wider range than at present, and have been pushed southward into their present restricted areas by the advance of the more powerful races which now surround them. If in their displacement they failed to mix with their invaders, their physical characters would remain pure, for isolation and long-continued interbreeding would preserve and even intensify the struc tural peculiarities of each race.

The enigma concerning the builders of the megalithic monuments on Ascension and Easter Islands, the Fijis, the Gilbert Islands, and Tongatabu, is simply restated, -the natives can neither account for them by tradition, or show physical evidence that their forefathers could have created such structures, nor are there any traces of races, pre-existing in the Pacific region, capable of such enterprises.

The study of the Patagonian and Fuegian skulls suggests interesting speculations as to the origin of the peoples of South America.

It is rather mortifying to find that our own countrymen have accomplished so little in the field of craniology, that in this exhaustive treatise there occurs but a single incidental allusion to any American authority.

Dr. Rudolph Bergh of Copenhagen, in an essay of 151 pages, with 311 figures of structural details beautifully drawn by himself (part xxvi. vol. x.), treats of the Nudibranchiata. The paper is purely descriptive and critical, and deals chiefly with the 25 forms collected by the expedition, which include 11 new species and 3 new genera. He gives, however, a list of all known forms in each genus

which comes up for discussion, the number sometimes being very large, as in Chromodoris with its 95 species. The remarkable new genus Bathydoris, dredged in mid-Pacific at depths of 14,550 feet, is described at great length, and elaborately figured.

The family Onchidiadae-modified shell-less pulmonates,' resembling in form certain nudibranchiates are treated of in an appendix, with historical and critical notes. Bergh believes that the tropical seas, though hitherto but slightly explored for nudibranchiates, will ultimately prove to be the headquarters of this group. The absence of allusions to American work emphasizes the fact, already pretty well appreciated on this side of the Atlantic, that in the study of this group there is an excellent opportunity for some one of our young naturalists who has not yet chosen a specialty.

The venerable George Busk prints part i. of his report upon the Polyzoa (part xxx. vol. x.), which treats of the Cheilostomata, enumerating 286 species from the Challenger's work, of which 180 are described as new. The workmanship of the paper is in the author's own peculiar style of excellence. There are nearly a thousand figures, and the pages devoted to an explanation of terms used in description are especially acceptable. The general conclusions arrived at by Mr. Busk are evidently withheld for the second part of his report. geographical and bathymetrical distributions of the group are treated at great length, and illustrated by an instructive map. Four species of Polyzoa were taken by the Challenger in the North Pacific at the depth of 3,125 fathoms; and one of these, Cribrilina monoceras, was taken in the Australian region at a depth of 35 fathoms, an instance of extensive range in depth unparalleled elsewhere.

The

Dr. Hoek's report upon the Cirripedia (part xxv. vol. viii.; part xxviii. vol. ix.), although the author mourns that his studies upon the deep-sea material have not yielded results equal to his own anticipations, is a very important contribution to zoology. It is printed in two parts, and is brimful of concisely stated observations and pregnant criticisms. It is an excellent example of the scholarly work which the naturalists of the Netherlands have of late been producing, and is no unworthy continuation of the classic memoir upon the same subject published a third of a century ago by Darwin. The systematic portion of the reports is devoted entirely to the description of the Challenger's collection, but in the introduction is given a critical review of all that has been discovered or written concerning the group since the time of Darwin, and also a new zoogeographical arrangement of all known species.

One of the most surprising of the recent reports is that by Dr. von Graff upon the Myzostomida of the expedition. Fifty-two of the 68 species discussed appear here for the first time. In fact, all the known species of the group have been brought to light by Dr. von Graff, with the exception of three described by Leuckart, by whom the genus Myzostoma was first discovered. These very remarkable animals, by Dr. von Graff placed among the arachnids, by other authorities among the worms, near Tomopteris, and only found parasitic upon and in crinoids, are being found in all the zoological collections, now that attention has at last been directed to their very inconspicuous existence. Twenty-two species, 14 of them new, are attributed to the explorations of the U.S. steamers Bibb, Hassler, Blake, and Corwin. A concise account of what is known concerning the Myzostomida serves as a preface, and there is a curious colored diagrammatic figure printed in with the text. The lithographic plates are exquisite.

In a second paper upon the Entomostraca (part xxiii. vol. viii.), Dr. G. Stewardson Brady treats of the Copepoda. His paper is mainly descriptive, and is, of course, prepared in his usual scholarly manner. There are 55 plates, diagrammatic and useful, but not artistic; and 142 pages of text, treating of 90 free-swimming species, and 15 fish parasites obtained by the Challenger, only one of which, Pontostratiotes abyssicola, dredged in a depth of 2,200 fathoms, is undoubtedly a deep-sea species.

The report upon the calcareous sponges, by Professor Poléjaeff of Odessa, a pupil of Schulze's, enumerates 30 species, 23 of which are new. A considerable portion of the paper is devoted to destructive criticism of the previous work of Professor Haeckel, and the construction of a new 'natural classification of the group. There are four superb plates of white sponges upon black backgrounds, as well as a number of anatomical figures beautifully drawn by the author.

Mr. Henry B. Brady's ponderous memoir on the Foraminifera, in two volumes, one of text, 814 pages; and one of illustrations, 115 plates and at least 2,000 figures,--is really a monographic revision of the entire group, with an exhaustive bibliography, from the year 1565 to the present time, and a chapter on classification, historical, critical, and constructive, leading up to an elaborate synopsis of families and genera. The synonomies and the tables of geographical distribution are made up in a very workmanlike manner, and the index is a delight to weary eyes.

The animals of this group are distributed everywhere over the ocean-bottom, as well as at the surface and in mid-waters. The presence or ab

sence of the calcareous shells of some of the pelagic species at different depths and in different localities is connected with some of the most important problems in oceanography. It was of the greatest importance that all questions relating to geographical and bathymetrical distributions should be discussed with reference to a thorough understanding of the relations of all existing forms; and it was, indeed, a fortunate thing that a naturalist so familiar with the Foraminifera as Mr. Brady should have undertaken this work.

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Mr. Brady, referring to certain views held by Dr. Wm. B. Carpenter and his colleagues concerning the existence or non-existence of true species amongst the lower Protozoa, which are, he admits, "from a purely biological stand-point. for the most part incontestable," holds that they really embody only one aspect of the subject. Although in some families, not merely reputed species, but reputed genera, are connected by a close array of intermediate modifications and dimorphous forms, and all sharp demarcations have ceased to exist, in others the successive modifications appear to be less closely connected, and to possess distinctive characters of greater persistence. Admitting," he writes, "the intimate relationship which often prevails throughout an entire generic group, admitting even that all the members of a genus may be referred to a common ancestral type, the question still remains how the different terms of each series are to be recognized. The various modifications which have been referred to differ not merely in details of form and structure, but in habit. They are met with under diverse conditions as to latitude, depth of water, nature of sea-bottom, and the like, and their modes of life are often totally distinct; furthermore, fossil specimens, with similar peculiarities, appear to have existed under precisely corresponding circumstances. Whether species' or not, the more important of them possess characters which afford means of easy identification, and it is obviously necessary that they should be provided with distinctive names." He admits the value, as a method of study of the plan proposed by Parker and Jones, in their memoirs on North Atlantic Foraminifera, of grouping the almost endless varieties of the Foraminifera around a small number of typical and sub-typical species, but denies that this plan may be made a basis of nomenclature. The binomial system must be retained, and it is impossible to deal with the multiferous varieties in this group without a much freer use of distinctive names than is permissible among animals endowed with more stable characters.

The chapter on the chemical composition of the tests of the Foraminifera possesses considerable

interest in connection with the study of bottom deposits. That upon pelagic species would be much more satisfactory to the reader if rather more definite conclusions could have been attained by the author of the memoir in a manner satisfactory to himself.

Eozoon is admitted to a place in the synopsis, but Mr. Brady does not commit himself to any opinions. In the introduction to his bibliography, he states that many of the titles of the less important contributions to the Eozoon controversy are admitted. The American names in the bibliography are those of Isaac Lea, the earliest, 1833, S.G. Morton, J. W. Bailey, E. de Verneuil, J. Hall, Meek and Hayden, G. G. Shumard, W. M. Gabb, J. W. Dawson, Count Pourtales, J. P. Whiteaves, C. A. White, H. A. Johnson and B. W. Thomas, T. A. Conrad, Angelo Heilprin, and J. Leidy.

The publication of the results of the Challenger is evidently being forwarded as rapidly as the limitations of painstaking research will permit. It is much to be regretted that the French zoologists who have the work of the Talisman and Travailleur in charge do not profit more by this example. G. BROWN GOODE. U.S. national museum.

DROUGHT AND WEATHERCOCKS. A WRITER in Symons's meteorological journal calls attention to a connection between drought and weathercocks. The connection does not always exist. Some weathercocks are entirely independent of drought or floods, and some are very seriously affected. The former are those which do not carry any of the usual letters N, E, S, W, or which are wholly of metal, and carried on metal or stone supports. The weathercocks which suffer from drought are those which have the cardinal points indicated by the letters, and which (though themselves of metal) are carried at the summit of a tall pole. The pole, under the influence of sun and drought, splits, and the cracks run nearly along its length, but not precisely. They are slightly inclined, and all run parallel. If the drought is prolonged, they become numerous, and, though no one crack may be a tenth of an inch, the aggregate amount becomes large. We have ourselves measured one on which the letters were, during the July drought, carried round 44°; the S letter was carried around until it pointed almost exactly S.W. With subsequent moisture the cracks have partly closed, and possibly by November the letter S will be nearly back in its true position; but as to this we have no knowledge. It is evidently necessary for observers to watch for the occurrence of this somewhat strange error.

FRIDAY, DECEMBER 18, 1885.

COMMENT AND CRITICISM.

In

THERE IS A POPULAR BELIEF that demand begets supply. If this be true, it would appear that the demand for good maps and atlases of this country, on small scales, is very limited. respect to culture, the published maps are fairly good, although in detail they are not what they should be, even in this respect. In their representation of natural features, however, they are, as a class, subject to severe criticism. It is not too sweeping an assertion to say that there is scarcely an atlas of this country which is abreast of our geographical knowledge, or even within several years of it. Indeed, in atlases dated '1884,' there are to be seen maps of the western states and territories, in which all geographical work, executed subsequent to the Pacific railroad explorations, has been ignored. The charitable might assume that the compilers were not aware of the existence of later and better material, were it not for the fact that in many atlases the same area is represented a second time by maps compiled from material of much more recent date. One must conclude that the same old plates have been made to do duty these many years, and that, while the culture has been revised from time to time, the natural features have not been considered of sufficient importance to warrant revision. On the most recent maps one still meets with the old familiar errors. The mouth of the Rio Dolores, in eastern Utah, is still frequently represented thirty miles out of place. The mythical island in Green River, in the Green River basin, is occasionally seen; and Sevier Lake, Utah, is sometimes accompanied by its double, the socalled Preuss Lake.'

But it is not in this respect alone that our maps and atlases are subject to criticism. As a rule, the representation of the relief is a dismal failure. There is scarcely a map published by private parties which gives even a fairly good picture of the orographic features of the country. No attempt is made, by means of contours, at a quantitative

No. 150-1885.

representation of relief, but hachures and crayon, or brush-work alone, are employed. In most cases the expression is in the highest degree conventional, a double line of hachures representing a range, and an asterisk a peak. When an attempt is made to represent properly the forms of relief, it is seldom successful. Through the ignorance of the compiler, the great ranges are belittled, while minor ridges take on an importance altogether disproportionate to their size. Every divide between drainage systems is represented as a mountain range. Plateaus appear as ranges, and ranges as plateaus. Another feature to be condemned is the raw and glaring colors by which the states, counties, etc., are distinguished from one another. If colors must be used, let them be subdued tints, which will not offend the eye, or render the map illegible. Many American maps and still more foreign maps are rendered almost illegible from the quantity of material which they contain. The names are so numerous as to obscure all other features, while the lettering is often so fine that it can be read only with a microscope. A map should be as legible as print. There is certainly room for improvement in the compilation and publication of maps.

IN THE INAUGURAL ADDRESS of President Adams of Cornell, reference is made to the need for the establishment of regular courses of instruction in the history and science of education at that university. According to the census of 1880, there are in the United States 64, 137 lawyers, 64,698 clergymen, 85,671 physicians, and 277,710 teachers. For each of the first three professions we demand a more or less special training. Sometimes we ask much, sometimes little; but we always require something, and in the more cultured sections of the country that something is a great deal. With our teachers the case is, or it may be more just to say has been, radically and incomprehensively different. Any person who chose could start a school, and various influences aside from special training served to secure responsible positions in institutions of learning. Teaching may, and perhaps does, require what we are used to hearing called a knack. But on what principle is it that teachers are not required to possess a scientific knowledge of their