mains, have still further confirmed the Silurian age of the only to the Upper Llandeilo series, the Lower Llandeilo

form of an anticlinal axis near the southern border of the Silurian area. This axis can be well seen in Roxburgh

The Moffat group, as represented in Wigtonshire, has a thickness of about 1,000 ft., of which more than half shire and Dumfriesshire, having a north-east and south-consists of flaggy greywacke beds. The underlying series, west direction. It has also been recognised by the the Ardwell group, probably attains to a much greater officers of the Geological Survey in Wigtonshire; and the thickness. rocks which it exhibits, which are the lowest in the Southern Uplands, have been designated by Prof. Geikie the "Ardwell group." This group is made up of "hard, well-bedded greywackes and grits, with bands of hard shale or slate. These rocks have a prevailing reddish or brownish hue, especially on weathered surfaces."

The third member of the Upper Llandeilo rocks of the Southern Uplands of Scotland, like the second, derives its name from Dumfriesshire. It is well exhibited in the hill called Queensberry, and has been designated the Queensberry grit group. The characters of this third member, as they are seen in Wigtonshire, in Wigtonshire, "consist of greywacke and grits in massive courses, with occasional bands of grey and greenish shales." Massiveness and regularity of bedding and jointing are the characters of this group. The sandstones are often coarse; and sometimes even coarse conglomerates appear, in which some of the embedded fragments are sometimes from 2 ft. to 3 ft. in diameter, a feature which distinguishes the Queensberry group from all the other members of the Upper Llandeilo rocks of the South of Scotland. Fossils appear to be absent from this group, no trace of them having been met with in the three parallel bands which traverse Wigtonshire.

In the Dumfriesshire portion of the Upper Llandeilo area of the South of Scotland, there have been recognised, above the Queensberry grit group, black shales with graptolites, the thickness of which have not yet been ascertained. To these black shales the name of Hartfell group has been given. As the typical area where these rocks occur is in the higher part of the Annandale district, the sheets of which have not yet been pub

the Geological Survey.

The Hartfell group is succeeded by the Daer group, which is made up of hard blue and purplish greywacke, and grey shales. It derives its name from a stream flowing from the north side of Queensberry into the Clyde. Its strata are greatly folded, and no reliable estimate can be formed of the thickness of the Daer group.

As seen in Dumfriesshire and Roxburghshire these low rocks have the same aspect and nature. They have afforded, both in Wigtonshire and Dumfriesshire, markings which have considerable resemblance to the fossil described by McCoy as Protovirgularia, and in Roxburghshire they have yielded crustacean tracks, but no other traces of organic remains have been obtained from them. Above the Ardwell group the officers of the Geological Survey recognise a mass of strata to which they have given the name of the "Lower or Moffat Shale group." This group is composed of "flaggy greywacke and grey shales," which are distinguished by the occurrence in them of several bands of black carbonaceous shales. These strata are well developed in the neighbourhood of Moffat, Dumfriesshire, from whence they derive their name. The black carbonaceous shales are very persistent, having been traced by the officers of the Survey from near Melrose to the western shores of Wigtonshire, "a distance of more than 100 miles." Three bands of carbonaceous shales can frequently be made out, but occasionally they come together so as to form one thicklished, we have at present no account of this group from band. These bands are very prolific in graptolites. They have, from their carbonaceous aspect, induced many persons, under the guidance of "practical miners," to expend large sums of money in search after coal, and some of the spots where they have been worked are known under the name of "coal heughs." Although the Moffat group is well developed through the greater portion of the Southern Uplands, it is on the coast of Wigtonshire that the best sections of the series can be seen. Here they are recognised resting on the Ardwell group, having at their base "grey and reddish shales, and clays, with calcareous bands and nodules, and enclosed bands of black shale, the lowest members being hard and flaggy." The second member of the Moffat group, as seen on the Wigtonshire coast, consists of black shales with intercalated clays, like the fire-clays of the coal-measures. Calcareous nodules and lenticular bands are also associated with the black shales, the whole being so intensely plicated as to render an attempt to determine their thickness extremely difficult. Upon the black shales well-bedded greywacke and grits occur with occasional shaly partings. These are succeeded by black shales so much jumbled and jointed, that their thickness cannot be made out. The next sequence consists of grey flagstones, flaggy sandstones, and grits, in beds of varying thickness up to 3 or 4 ft., with abundant partings of grey shale. these succeed a thick band of finely laminated grey shale, 3 or 4 ft. Black shales, bands 12 to 18 ft. in thickness, occur next, and the highest members of the group consist of fissile shales.

The Hartfell shales of the Daer group seem to thin out towards the south-west. They have not been distinctly recognised in Wigtonshire, where the Dalveen group, which in Dumfriesshire succeeds the Daer group, is seen resting conformably upon the Queensberry grits.

In Dumfriesshire the Dalveen group consists of fine blue and grey greywacke, and shales having no features distinguishing them from other members of the upper Llandeilo rocks. Their estimated thickness is about 2,900 ft. They are well exposed in Dalveen Pass, Dumfriesshire, whence their name, and in Dinabid Linn they are seen passing under a coarse pebbly rock, "Haggis Rock."

In Wigtonshire the lower part of the Dalveen group is seen overlying the Queensberry rocks south of Corsewell Lighthouse. Here its lower portion is remarkably shaly, but thick masses of greywacke also occur. Among the shaley beds are some bands worked at Cairn Ryan for To slates. These slates have long been known as affording graptolites; and another thin band of black shale also containing the same fossils appears in this group in Wigtonshire.

In Dumfriesshire above the Dalveen group a series of

table old associations have united to form societies of a kind which entitle them to be regarded as Local Scientific Societies, and even Field-Clubs. Still, all these older societies, as they existed previous to 1830, differed in many essential respects from the Local Societies and Field-Clubs which began to spring up about that time; even the well-known Literary and Philosophical Society of Manchester, quite on a par with some of the best London Societies, and which has produced original work of the highest value, has been all along confined to the learned and professional men of the city and neigh

coarse and fine grits and greywacke, having red and green bands of flinty mudstone, conglomerate, and occasional breccia associated with them, occur—a persistent band of conglomerate containing quartz-rock pebbles, Lydian stone, and jasper characterise this group. The conglomerate, being locally known as "Haggis Rock," has furnished the name to the series, which is about 1,800 feet thick. The Haggis group in Dumfriesshire is seen striking across the river Afton, also, along the N.W. flanks of the Lowther hills, and elsewhere in this county. More to the north it can be recognised along the north-western margin of the Silurian area in Craw-bourhood, who have made use of the meetings of the fordjohn, Lanarkshire. The Haggis rock is not persistent in its character. To the N.E. this conglomerate becomes much finer in grain, and passes "into a gritty greywacke." This group has hitherto yielded no fossils. In Wigtonshire the Haggis rock cannot be distinguished as a distinct series; its characteristic conglomerate being, as already seen, of local occurrence, it does not appear to manifest itself in the Silurians in the S.W. of Scotland. (To be continued.)

I'

LOCAL SCIENTIFIC SOCIETIES

N very many ways has the general advance of intelligence, elevation of taste, and spread of education been shown during the present century, and more especially during the last thirty years; one of these ways is undoubtedly the increasingly rapid spread of Local Scientific Societies. What we mean by a "Local Scientific Society," as distinguished from the large Societies of London, is an association of individuals in a particular locality for the common study of one or more branches of science, by the reading of original papers, and what is perhaps of more importance, the actual investigation of the natural history-geology, zoology, botany, meteorology-and archæology of its district. Of the societies established within the last thirty years, nearly all are marked by these characteristics; such at all events is their professed object, and we are glad to say that, to judge from the special reports which we have received, and the numerous printed "Proceedings" of greater or less pretensions which are sent us from time to time, a very large proportion creditably carry out their programme.

In a number of the principal towns of England and Scotland associations exist, dating, some of them, from the end of last century, known as " Literary and Philosophical Societies," or by some similar title. These are generally comparatively wealthy, possessed of good buildings containing a library, museum, reading-rooms, lecture-hall, &c., with a large body of members belonging to the middle and upper classes. These, however, so far as their original objects are concerned, with one or two exceptions, scarcely come under the category of Local Scientific Societies, in the sense of the definition given above, though many of them, stimulated by the growing taste for Science, have recently added to their usual courses of lectures on literary subjects, others on subjects connected with Science, and have even organised classes for the study, under competent lecturers or teachers, of one or more branches of Science. In some instances, moreover, a few of the members of these respec

Society for the purpose of making known the results of their independent scientific investigations.

So far as can be ascertained, the society just mentioned is the oldest provincial society which can be considered as in any way scientific, having been established in 1784, for the purpose of diffusing "literary and scientific intelligence, and of promoting the literary and scientific inquiries of learned men in the town and neighbourhood." "The results of its labours," Sir Walter Elliott says, in his valuable address to the Edinburgh Botanical Society, in 1870, on this subject, were published in Memoirs,' the first volume of which appeared in 1785, at which time James Massey was president, and Thomas Barnes, D.D., and Thomas Henry, F.R.S., were Secretaries. Five volumes had appeared up to 1802. In 1805 a second series commenced under the Rev. John Walker, President, and John Hall and John Dalton, Secretaries, which had extended to five volumeș more in 1860. A third series was commenced in 1862, and has reached volume xiii. The second series is enriched with many papers by Dalton, including the first development of the atomic theory." In 1858 a microscopical and natural history section was established; the latter, however, we regret to say, is since defunct.

The next society of this class in order of time was instituted at Perth in 1781, as the Perth Literary and Antiquarian Society; we need not say that, so far as eminence is concerned, it was never to be compared with the Manchester Society. It has never done scientific work of any value, though it possesses a handsome building, with a museum, devoted mostly to antiquities, but having a fine natural history collection as well, and a good library. Like many other societies of a similar kind, its building serves as a kind of meeting-place or club, where those members who have nothing to do can meet and have a gossip, and read the papers. This society has published only one volume of "Transactions" (in 1827), but so far as we know, they have now no transactions to record. A few years ago, as will be seen from our list in Vol. viii. p. 521, a Natural Science Society was established in the county, with Perth as its headquarters, which gives promise of being one of the best working Local Scientific Societies in the kingdom.

In 1801 a society of a similar kind was established in the sister kingdom, the Literary Society of Belfast, which has never done anything to call for note here. Previous to this, however, in 1793, the Newcastle-on-Tyne Literary and Philosophical Society was established, which, although it has published only one volume of memoirs, and is little more than the owner of an excellent public library, does good work by providing educational courses of lectures for in

struction in mathematics, chemistry, and other branches Royal Institution of South Wales (Swansea), and the Isle of science as well as literature.

THORPE'S QUANTITATIVE ANALYSIS"

Quantitative Chemical Analysis.

By T. E. Thorpe, Ph.D., F.R.S.E., Professor of Chemistry, Andersonian University, Glasgow. (Longmans.)

WE welcome with pleasure a work which in the pre

sent state of our literature on Quantitative Chemical Analysis, may well be looked upon as a boon to the advanced chemical student. Fresenius's Quantitative Analysis has been so generally accepted by chemists as the standard book in this branch of Science, that we greatly regretted the unwarrantable liberties taken by the English editor in the late edition of our trusty author's work. The publishers, who did not, in justice to the accomplished author, recall that edition, may yet learn that the chemical public, at all events, know how to appreciate a good work on Quantitative Analysis. We confess to a feeling of relief, speaking as a teacher of chemical analysis, as we perused Mr. Thorpe's book; for although we have to differ from the author on some minor matters, we believe that this new work will speedily be found in the hands of every chemical student.

Our author has evidently felt what others have experienced before him, that Fresenius's Quantitative Analysis became with every new edition more and more unwieldy (we are speaking of the German editions), and that, at the commencement at least, a simpler guide to quantitative analysis might with advantage be placed in the hands of the student. As methods of analysis--especially volumetric methods - multiplied year after year, the teacher and the student looked to the master for some indications which methods should, under given circumstances, be adopted in preference to others. Mr. Thorpe has evidently been bent upon supplying this want. In the treatment of his subject he has followed the example set by Woehler in his "Practische Uebungen in der Chemischen Analyse," rather than that of Fresenius. It appears to us, however, that he has somewhat fallen into the other extreme, for, in the place of a series of carefully elaborated methods for the determination of each base and acid, he has contented himself with giving a few examples only of individual determinations, and has preferred to teach quantitative separations almost exclusively by describing, in language both terse and concise, a number of complex quantitative analyses, such as are likely to occur in practice. There is much to be said for this plan of teaching analysis, so to speak, en bloc. It involves, however, much repetition, or, at the very best, reference from one example to another, and leaves the student in considerable uncertainty whenever he has to break new ground. The aim of all quantitative teaching should be to enable the analyst to adopt or devise for himself correct methods of separation. The foundation for quantitative methods should, in fact, be laid by careful and accurate qualitative work. A good workable method may often be preferable to a more elaborate although more strictly accurate method. In the endeavour to write as compactly as possible, the author has frequently over-estimated the mental powers and the chemical knowledge, say of second years' students, for whose use the work is apparently written, and has thus sacrificed clearness for briefness. We refer, for instance, to the methods given for the separation of iron, manganese, &c. in Spiegeleisen, condensed as it appears,

from Fresenius, where the ammonium carbonate method occurs, but where it would be difficult for a student, without the teacher's assistance, to trace the chemical changes. There is too much of the how to do a thing, and too little of the why to do it throughout the work, to make it as useful to the beginner as it would otherwise be. Although the several methods for the separation of manganese from iron, &c., are to be found in different parts of the book, there are scarcely sufficient hints, why and under what circumstances and conditions the one method is to be used in preference of the other. The same applies to various other methods of separation. Well known and familiar chemical methods, again, are abandoned, occasionally, for new methods of at least questionable utility. We may mention, among such, the use of hydrochloric acid, as the starting-point in alkalimetry.

The same remark applies to the apparatus described and illustrated. The woodcut on p. 142 ex. gr., illustrative of the method for taking the specific gravity of ammonia, looks startlingly elaborate. Much credit is due, however, to the author and his coadjutor, Mr. Dugald Clerk, for the care bestowed upon the preparation of the woodcuts. We consider them, for the most part, well selected and well executed. There is that pleasing evidence to the chemical eye, that the illustrations have originated in the laboratory, and that they depict apparatus which can be practically used, and are not merely put in to please and catch the eye. In fact, when we compare some high-priced books of the class, which it would not be difficult to enumerate, with the elegantly gotup and cheap volume of Mr. Thorpe, we can only congratulate him on the book he has produced.

If we may be allowed to tender advice, we should say :-Condense the part on the operations of weighing; enlarge the number of examples of simple gravimetric analysis, so as to include the more important acids and bases; draw a line between determinations usually required in analyses for practical or commercial purposes, and the more elaborate complete analysis of the same bodies; and last, but not least, explain more fully, why and when one method answers better than another-if only in compassion for the weaker analyst.

We cordially recommend the book, and hope to see these suggestions adopted in the next edition, for which in all likelihood we shall not have to wait long.

LETTERS TO THE EDITOR [The Editor does not hold himself responsible for opinions extressed by his correspondents. No notice is taken of anonymous communications.]

The Management of the British Museum

I BEG to protest against the remarks upon the management of The general question whether a public institution of the sort is the British Museum contained in your article of November 6. best governed by a public official or by a body of Trustees, may very likely admit of much discussion, but the decision should not be prejudiced by totally ignoring the noble work which has been and is being done by the Museum. No scientific man surely can be ignorant that the British Museum exists not so much for the momentary amusement of gaping crowds of country people, who do not understand a single object on which they gaze, as for the promotion of scientific discovery, and the adthe indifference of the Museum Trustees to the best interests of vancement of literary and historical inquiry. We are told about science, but we are not reminded frequently enough that it is