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Comprising Fossils, Minerals, and Rocks, labelled with Name, Locality

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EDINBURGH, May 31, 1889. DEAR SIR, I have just returned from a six weeks' stay at the Ben Nevis Observatory, and while there had an opportunity of testing the admirable qualities of your new "Watkin" Aneroid. The result has been most satisfactory, the extreme error noted being only about the one-hundredth of an inch. During my stay at the Observatory the Aneroid was frequently tested by taking it down a couple of thousand feet and then Observer, Scott. Met. Soc. comparing it with the standard on my return. The R. C. MOSSMAN, F.R.M.S., results obtained speak volumes for the high-class work manship and great accuracy you have attained in the manufacture of this instrument. (Signed)

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MAKER:

J. J. HICKS,

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FOR

THURSDAY, DECEMBER 19, 1889.

THE EPIDEMIC OF INFLUENZA.

OR the first time after an immunity of nearly half a century, our country is again threatened with an epidemic of influenza. The accounts we receive of epidemic illness in Russia, in Germany, and last of all Paris, seem to make its irruption here every week more mmment. The question will, however, naturally be asked She public, whether there is any real ground, in the netry and in what is known of the nature of the disease, for such an apprehension? Is it a disease really brought from a distance? Is it anything more than the general prevalence of catarrhal affections, of colds and coughs, which the time of year, and the remarkably unsettled weather we have lately experienced, make readily explicable without any foreign importation? Indeed, is intiuenza, after all, anything more than a severe form of the fashionable complaint of the season?

To answer the last question first, and so to put it by, there can be little doubt that influenza is a distinct, specine affection, and not a mere modification of the common cold. The grounds for this belief cannot be fully stated here, but may be gathered by reference to the descriptions of the disease as seen in former outbreaks by physicians of the older generation; for instance, by Sir Thomas Watson in his classical "Principles of by sic," or the late Dr. Peacock in his article in Quain's Dictionary of Medicine."

These symptoms, the history of the disease, and its stribution, all justify us in treating it as a distinct and ecinc disease, which when it is prevalent will rarely be staken, though, with regard to isolated and sporadic 1es, dimculties of diagnosis may arise. About its nature, or its affinities with other diseases, it is unnecessary to speculate. It will be sufficient to inquire what its recorded history in the past justifies us in expecting as its behaviour in the future. There are few cases in which history proves so important an element in the scientific conception of a disease as it does in that of fluenza. For hardly any disease shows a more marked endency to occur in epidemics-that is, in outbreaks strictly limited in point of time. After long intervals of naction or apparent death, it springs up again. Its bronology is very remarkable. Though probably occurng in Europe from very early times, it first emerged as 4 definitely known historical epidemic in the year 1510. ace then, more than 100 general European epidemics have been recorded, besides nearly as many more limited to certain localities. Many of them have in their origin and progress exhibited the type to which that of the present year seems to conform. We need not go further ack than the great epidemic of 1782, first traceable in Kassia, though there believed to have been derived from

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In St. Petersburg, on January 2, coincidently with a remarkable rise of temperature from 35° F. below freezing to 5 above, 40,000 persons are said to have een simultaneously taken ill. Thence the disease spread Over the Continent, where one-half of the inhabitants were supposed to have been affected, and reached England in VOL. XLI.-NO. 1051.

May. It was a remarkable feature in this epidemic that two fleets which left Portsmouth about the same time were attacked by influenza at sea about the same day, though they had no communication with each other or with the shore.

There were many epidemics in the first half of this century; and the most important of them showed a similar course and geographical distribution. In 1830 started a formidable epidemic, the origin of which is referred to China, but which at all events by the end of the year had invaded Russia, and broke out in Petersburg in January 1831. Germany and France were overrun in the spring, and by June it had reached England. Again, two years later, in January 1833, there was an outbreak in Russia, which spread to Germany and France successively, and on April 3, the first cases of influenza were seen in our metropolis; "all London," in Watson's words, "being smitten with it on that and the following day." On this same fateful day Watson records that a ship approaching the Devonshire coast was suddenly smitten with influenza, and within half an hour forty men were ill. In 1836 another epidemic appeared in Russia; and in January 1837, Berlin and London were almost simultaneously attacked. Ten years later, in 1847, the last great epidemic raged in our own country, and was very severe in November, having been observed in Petersburg in March, and having prevailed very generally all over Europe.

Some of these epidemics are believed to have travelled still further westward, to America; but the evidence on this point seems less conclusive. Without entering on further historical details, and without speculating on the nature of the disease, we may conclude that these broad facts are enough to show that a more or less rapid extension from east to west has been the rule in most of the great European epidemics of influenza; and that therefore its successive appearance in Russia, Germany, and France, makes its extension to our own country in the highest degree probable.

There are, it is true, certain facts on the other side, but they appear much less cogent. Since our last great visitation, certain epidemics of influenza have been recorded on the Continent which have not reached our shores.

One was that of Paris in 1866-67; another at Berlin in 1874-75, of a disease described by the German doctors as influenza, and of great severity, affecting all classes of society. But in all epidemic and even contagious diseases there are outbreaks which seem to be self-limited from the first, showing no tendency to spread. This has been notably the case with plague and cholera. On the other hand, when an epidemic shows an expansive and progressive character, it is impossible to predict the extent to which it may spread. And the present epidemic, it must be confessed, appears to have this expansive character.

Many interesting points are suggested by this historical retrospect. What is the meaning of the westward spread of influenza, of cholera, and other diseases? Is it a universal law? To this it must be said, that it is by no means the universal law even with influenza, which has spread through other parts of the world in every kind of direction, but it does seem to hold good for Europe, at least in the northern parts. The significance of this law,

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as of the intermittent appearances of influenza, probably is that this is in Europe not an indigenous disease, but one imported from Asia. Possibly we may some day track it to its original home in the East, as the old plague and the modern cholera have been traced.

As regards, however, the European distribution of influenza, it has often been thought to depend upon the prevalence of easterly and north-easterly winds. There are many reasons for thinking that the contagium of this disease is borne through the air by winds rather than by human intercourse. One reason for thinking so is that it does not appear to travel along the lines of human communications, and, as is seen in the infection of ships at sea, is capable of making considerable leaps. The mode of transmission, too, would explain the remarkable facts noticed above of the sudden outbreak of the disease in certain places, and its attacking so many people simultaneously, which could hardly be the case if the infection had to be transmitted from one person to another.

Another important question, and one certain to be often asked, is suggested by the last-namely, whether influenza is conta gious. During former epidemics great care was taken to collect the experience of the profession on this point, and its difficulty is shown by the fact that opinions were much divided. Some thought the disease could be transmitted by direct contagion, while others doubted it. But there was and is a general agreement that this is not the chief way in which the disease spreads, either in a single town, or from place to place.

We must avoid the fascinating topic of the cause of influenza, or our limits would be speedily outrun. But one simple lesson may be drawn from the facts already mentioned-namely, that the disease is not produced by

any

kind of weather, though that, of all possible causes of disease, is the one most often incriminated in this country. It is true that some of our worst epidemics have occurred in winter, but several have happened in summer; and the disease has been known in all parts of the world, in every variety of climate and atmospheric condition; so that it is certainly not due to a little more or less of heat or cold, moisture or dryness. Its constancy of type, the mode of its transmission, its independence of climatic and seasonal conditions, all suggest that its cause is "specific,”—that is, having the properties of growth and multiplication which belong to a living thing.

Whether the disease affects the lower animals is not

now.

the epidemic became noticeable in Petersburg, where according to a correspondent of the British Media Journal, it began on November 15 or 17, thoug: sporadic cases had undoubtedly occurred earlier. In the beginning of December it was already widely spre throughout Russsia, and, as it would seem from the pub lished accounts, must have been in Berlin about the same time. In Paris the first admitted and recorded cases occurred about December 10, though doubtless there were cases before that date. Both public and private accounts report it exceedingly prevalent there In London, notwithstanding the abundance of colds and coughs, and the mysterious rumours whet have been afloat, it appears to the present writer douteful whether any cases of true influenza have yet occurred. But according to its apparent rate of progress, it migh if coming from Paris, have already arrived here; and it may be breaking out even while these lines are going through the press. But, on the whole, one would be disposed to give the epidemic another week or two. If its distribution depends, as it seems to do, on the winds, it is impo sible to prophesy with much plausibility. A steady breest setting in from one of the affected places might bring us an invasion in a very short time; but the current of au would have to be continuous over the whole district Light local winds, whatever their direction, would, if the hypothesis be correct, have little effect. On the othe hand, a steady frost, with an "anticyclone" period, might effectually keep off the disease. If, then, there is anything in the views above stated, prophecy belongs rather to the province of the weather-doctors than of the medical doctors.

Should the prospect seem a grave one, it may be some consolation to remember that an epidemic of influenza rarely lasts more than a few weeks-three to six-in one place; that it is rarely a fatal disease, though affecting large numbers of people; and that the present epidemic seems to have displayed on the Continent a decidedly mild type, which, according to the general rule, it is likely to retain. J. F. P.

THE HORNY SPONGES.

A Monograph of the Horny Sponges. By Robert von Lendenfeld. (London: Published for the Royal Society by Trübner and Co., Ludgate Hill, 1889.)

absolutely certain, but the human epidemic has often WITHIN the last few years, and as a direct result of

been preceded or accompanied by an epidemic among horses of a very similar disease. It is pretty well known that such a disease is now very prevalent among horses in London. Nearly three weeks ago, one of the railway companies in London had 120 horses on the sick list, and the epidemic is still by no means extinguished. To a certain extent this must be taken as prognostic of human influenza.

It may be asked, if the influenza is really to come, can we form any notion how soon it is likely to appear? On such a point little beyond speculation is possible, for the rate at which the disease travels is extremely variable. Generally, it has taken some weeks, or even months, to traverse Europe, but occasionally much less, as, for instance, in 1833, when it appeared to travel from Berlin to Paris in two days. It is now barely a month since

the famous Expedition of the Challenger, three most important monographs of the sponges belonging to the groups of the Hexactinellida, Monaxonida, and the Tetractinellida have been published, nor must the valuable contributions by Poléjaeff to the history of the remaining groups, Calcarea and Keratosa, be overlooked. The Calcarea had the advantage of having been already monographed by Haeckel, and so there only remained the Horny Sponges to be fully described, in order tha the natural history of the sponges should be up to date

Such a work has now been accomplished-thanks to the liberality of the Royal Society-by the labour and scientific skill of Dr. Robert von Lendenfeld. This monograph forms a fine quarto volume of over 900 pages, with an atlas of fifty lithographed plates.

While a student at the University of Graz, Lendenfeld

ells us, his time was chiefly spent in the zoological laborstory of Prof. F. E. Schulze, then engaged on those rearches on the natural history of sponges with which *.5 name will ever be associated. This led him to take a special intest in the group, and to work out its history, in the Mediterranean, and then at Melbourne and ner places on the southern coast of Australia-a coast edingly rich in organisms of this class. From Melune, New Zealand was visited, and the Christchurch nd Dunedin collections were examined. Next, that aparent El Dorado of the spongologist, Sydney, was exored, and, thanks to the splendid liberality of Sir Witam Macleay, Lendenfeld was enabled to establish laboratory at the water-edge, and to study in a very rough manner the sponges of this district.

With such abundant material, and with such ready 1p, nothing was wanting to work out the structural history of the species of the group. But to describe and me them, reference to type specimens was, above all things, necessary, and these latter were to be found most conveniently in the British Museum; thither, therefore, Lendenfeld came, early in 1886, at first resolved to write account of the Australian Horny Sponges; but fortanately finding, during the progress of this work, that so great a proportion of the known forms were Austraan, he determined to make a complete monograph of the group, and hence the volume which we proceed to

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This monograph of the Horny Sponges is divided into | hee parts: (1) an introduction, containing a brief historical summary and a detailed list of publications relatIL to sponges; (2) an analytical portion, devoted to the wystematic description of all the known Horny Sponges; and 3) a synthetical part, in which the anatomy and physiology of sponges, especially of Horny Sponges, are rrated, and their phylogeny, systematic position, and Classication discussed.

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Of the very extensive and scattered literature relating to the sponges, a most excellent bibliography is given; papers are arranged alphabetically under their authors' 1. mes, but the publications of each author are given bronologically; the number of pages in each memoir is ♫ 12a, but, unfortunately, no reference is made to illustraT Ros; abstracts and translations of papers are always

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Considering the genus as "the important unit," the talytual part consists essentially of a series of monoaphs of the genera of Horny Sponges, but "species such are described; and the author has "done his to make the different species equivalent," though le has been difficult of achievement. In those cases where he has felt compelled to establish varieties, he has wed the plan of E. Haeckel and F. E. Schulze, and as divided the whole species into "the requisite number equivalent varieties." The total number of the species divaneties described amounts to 348, of which no less an 258 have been found in the Australian area.

It would not be possible, within any reasonable space, give any satisfactory details of the analytical portion this monograph. The descriptions of each genus are suped into an historical introduction; a sketch of the -pe, size, colour, surface, and rigidity characteristic of "group; an account of the canal system, skeleton,

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with notes on the histology and physiology; the affinities of the genus; statistics of the species, with a key thereto, and details of distribution. Doubts must of necessity arise as to the exact limits that each author would ascribe to the species described by him, and in doubtful cases of this sort Dr. Lendenfeld has adopted the plan of placing no authors' names after them, but gives a full list of synonyms; we think it a pity that in these lists the memoirs, instead of being quoted, are simply referred to by numbers, for the explanation of which one must refer to the bibliographical list.

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It is in the synthetical part, in which the general results are discussed, that the chief interest of this work lies, at least for the general reader. Here we have the questions of the general structure and evolution of sponges as a group considered, and their classification and systematic position discussed; and finally, as the fashion of some authors is, "an ancestral tree of the families" is given. Starting with the story of the metamorphic development of sponges, we find the primitive sponge defined as consisting of a simple ento- and ectoderm, and a thin mesogloa-a very primitive mesoderm-between the two. Dr. Lendenfeld thinks that it is now generally acknowledged that the Physemaria, which Haeckel considered as Gastreaden der Gegenwart," are not sponges at all, but Protozoa, so that they need not here be taken into account. Of course, it is evident that the views about these Physemarias, held at present by Haeckel, were, at the time of his thus writing, unknown to Dr. Lendenfeld. The modified Gastræa is traced onwards in its development, and the morphology of the adult structures are passed under review; their want of symmetry-and the exceptions are but few-is noted. None of the Horny Sponges are green; blue is never observed in the group, the range of colour being from light yellow to dark brown, light to dark red, and light to a dark, almost black, violet; the colour is lost in all, with a few exceptions, such as in Aplysilla violacea, when the sponge is preserved. The Horny Sponges would seem never to imitate their surroundings in colour, but it is suggested that in some cases the intense vivid colours may have the effect of frightening their enemies. An attempt is made to account for the shape of the sponge conuli as the result of two pressure forces and to express this by formula. The biological student will scarcely be grateful for this, and is likely to be bewildered when he reads that "the conuli are hyperbolic rotatory bodies, formed by the rotating of the hyperbola,

y = (p. x), (t + t . x),

round an axis parallel to the direction of pressure through the summit of the conulus." The canal system is described in some detail, the author not confining himself to the Horny Sponges. In contrasting this system in the Hexactinellida and the Hexaceratina, there seems some little confusion as to the comparative "tenderness" of the structures. The absence of spicules (siliceous) in the fibres is considered as the characteristic feature of the Horny Sponges, which distinguishes them from their siliceous ancestors; but in the superficial fibres of Aulena, echinating proper spicules occur; in the ground substance of several genera of Spongeliada, microsclera are

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