ABSOLUTELY ‘PURE, therefore BEST, ‘The standard of highest Purity.” — The Lancet. eSTABLISHED 1865 ) RO a p\. Ss SCIENCE-GOSSI/P. 321 GEOLOGICAL NOTES IN THE ORANGE RIVER COLONY. By Major B. M. SKINNER, R.A.M.C. 1e a former article (SCIENCE-GOSSIP, vol. vii., No. 74, p. 185) it was pointed out that Bloem- fontein occupies a position where the Karroo strata pass up into the Molteno group of the Stormberg strata. The railway station, level 4,517 feet, marks fairly exactly the altitude at which this change takes place. Above this point sandstones predominate, while below mudstones prevail. Borings made below this level show casts of mudstones, chiefly blue grey, sometimes purplish in tint, with thin bands of sandstone, the same condition being seen in the banks of that of the modern wildebeeste. This particular spot was a most exceptional one among many scores of similar diluvia visited, in that, in addi- tion to the horn-core, two shells of a small Succinea were found in a carbonaceous layer. Another exception which may be noted was a sec- tion in the stream-bank west of the town, which provided, five feet below the surface, the stone of a peach, lying in a sandy layer of diluvium. The result of disintegration of the rocks has been the formation of two classes of soil, sand and clay; there are also soils formed from the BED AND BANK OF THE BLOEMSPRUIT. dongas and in the Bloemspruit. The subjoined photograph, taken in the Bloemspruit about two miles east of the town, shows the bed and lower bank of this stream, where the outcropping rock was of this character. The white band is traver- tine, covering denuded mudstone. Above the travertine is modern diluvium. The modern diluvium in this bank—and it is of much the same character elsewhere—varies in places, being sometimes chiefly sand, sometimes clay, or a mixture of the two. In some parts the strata of clay or sand show patches of darker tint, and occasionally of black carbonaceous material, in which the forms of ferns and grasses may be distinguished, generally too friable to be pre- served. Near one of these patches, a little below the site of the photograph, some eight feet below the surface, and embedded in a carbonaceous sandy clay, a horn-core was discovered, resembling APRIL 1902.—No. 95, Vou. VIII. admixture of these, also a black soil, which is a carbonaceous clay. The last has been formed, whenever found, in localised patches near dolerite hills. It is the result of denudation of dolerite accumulated in an area to which there was no outflow, until the level of the top of the obstruc- tion had been reached, and consequently marks the sites of small bogs. In the present day such patches of black soil are not extensive, and are deeply furrowed by the rush of rain water to lower regions. The pure clay soil is usually found only at the foot of a dolerite hill. It contains boulders of dolerite which are disintegrating, but doing so more slowly than when exposed to air only. Some of these have been denuded through removal of the surrounding clay for brickmaking purposes, and lie in the middle of a clay quarry on the talus slope near New Fort Kop. Seen alone they might be suggestive of other means of production. eo ob a The dolerite in disintegrating, besides forming the ferruginous clay above mentioned, supplies the lime which washes down and forms the travertine beneath the diluvium of the valley, and also gives up some magnesia, which is traced in the well- water of the vicinity. The sandstone rocks supply the vast quantities of sand which form the greater part of the beds of the larger rivers, sometimes very loose and crumbling, at others stiffened with some of the clay from the dolerite. Occasionally interbedded with the sand, dark carbonaceous patches mark the sites of former vegetation, producing ribbon-like dark grey or black streaks, in the banks of the spruits. Returning to the older rocks, the sandstones and grits which are found as one ascends from the railway level are seen again on Sussex Hill (see S.-G., map, p. 104, vol. vii.), and lying loose on these rocks silicified wood, fragmentary, is occasionally found. On proceeding §.E. from this hill for about a mile a whole tree was discovered, just above the level of Bloemfontein station, lying in strata of thin sandstones and mudstones. The tree was lying with its roots at a slightly higher level than its branches, having evidently drifted down to this position, where in all probability it still remains, for efforts which were in progress for its removal to the Bloemfontein Museum were cut short through the writer having to proceed to another post. Frag- ments of silicified wood were also observed a little south of Spitz Kop. According to Stow, the Molteno strata were occupied by vast forests of coniferous trees, which are found copiously in certain localities, and generally overlie Coal- measures. It may be noted here that a rock described in SCIENCE-GOssIP, vol. vii. p. 34, as appearing like chert was the same as that described on p. 103 as “ black, with conchoidal fracture and white streak,” and was found afterwards to be carbonaceous shale, metamorphosed by contact with dolerite, the continuation of the same rock near the dolerite being unaffected by the intrusive rock. Since coming to this conclusion, it’ suggests itself that the rock described by Stow in “ Quarterly Journal Geological Society,” vol. xxx., No. 120, p. 620, may be of a similar nature. Proceeding northwards from Bloemfontein along the Brandfort Road, Deale’s Farm is passed, just beyond which is the exposure noted on p. 134 of vol. vil. Near this kloof is a flat-topped hill, Plaat Kop. The top of this hill is formed by a dolerite cap; beneath that is a grit which shows signs of denudation previous to its having been covered, while its upper part has been metamorphosed by the overflow. Beneath the grit come the usual sandstones of varyine structure, while in the dongas below the base of the hill blue-grey shales are exposed. Rejoining the road, leaving Plaat Kop on the left, the grass-covered surface of the SCIENCE-GOSSIP. country slopes gradually towards the Rhenoster Spruit, which, where the road approaches it, winds through gorges cut through dolerite, its modern banks being formed of brick earth, and lined with plentiful mimosa. Its bed in places shows the dolerite rock. After clearing these hills, shelving diluvial country leads down to Glen, on the banks of the Modder River. Here is the bridge for the railway running northwards, blown up by the Boers shortly after the occupation of Bloemfontein by our troops. but now reconstructed. The banks of the river are cut out of sand, in which a few sec- tions of mudstones are occasionally visible. These mudstones are well exposed in the bed of the river. The river level here was made to be 4,325 feet; that of the Rhenoster, where crossed a short dis- tance above by the road, was 4,375 feet altitude. Wimbledon, February 16th, 1902. THE PLUM AND ITS- ALLIES: 3Y SOPHIA ARMITT. N March and April, before the great rush’ of spring flowers begins, while they are yet few and therefore precious, only the starry celandine, violets sweet and otherwise, coltsfoot, gorse, golden saxifrage, mercury, marsh marigold, perhaps a stray primrose or an early windflower, occur the blossoming of many plum trees and the blooming of the blackthorn in the leafless hedges. Gilbert White’s date for it is April 7th to May 10th. Other observers have placed it as early as March 16th. In Mr. Preston’s ‘ Flora of Wiltshire ” the earliest flowering is February 20th, 1869, and the latest May 5th, 1879. A little later by about a week comes the bullace, and later still the flowers of the - wild plum; but all of them generally bloom in April. These three—sloe or blackthorn, bullace, and plum-—are classed together under the common specific name of Prunus communis, and separately as sub-species called respectively P. spinosa, P. insititia, P. domestica. ‘The sloe, or blackthorn, is. very different from the other two. It is thorny while they are not; its branches spread out at right angles as theirs do not;.its flowers appear before the leaves, while the others produce flowers and leaves simultaneously. The black fruit of the sloe is upright, round, and sour; that of the others is. hanging, elliptical, or ovoid, and sweet-flavoured, as well as much larger. The blackthorn is much more abundant and more widely spread in this country; it is wild in Europe only; while the native home of the others is Western Asia and Northern Africa. It is more than doubtful if the wild plum is native to Europe, since in the south, where it is supposed to be so, this species is living in hedges and near dwellings with the appearance of a tree scarcely naturalised. Bullace is to be found apparently wild south of the Alps, in Turkey, and the regions round the SCIENCE-GOSSTP. 323 Caspian; but it is likely that, though the hardy form with the round fruit may possibly have been native to Europe, the improved form has travelled like the plum from its original home in Asia. That the bullace and wild plum may have had a common origin is more conceivable than that the sloe should have shared their ancestry. This matter, which brings us to the difficult subject of origins of cultivated plants, is, like all origins, wrap- ped in mystery. These plants are far too new in the world’s history to be found in the geological record ; we can go no further back in their story than-to the remains of the lake dwellers of Italy, Switzer- land, and Savoy, and the record there is not very easily read. In those remains are found many stones of the blackthorn, few, and from one place only, stones of Prunus insititia, and no stones at all of P. domestica. The ancient people who lived above piles driven into shallow lakes must have fared hardly, since they fed upon sour berries that we deem uneatable, though they may have been in a cooked state. From,this it may be inferred that the wild plum in its half-naturalised state has not been in Europe more than some two thousand years. From the fact that Cato only once mentions Prunus, it is supposed that there could be no cultiva- tion of the plum tree in orchards in his time. Virgil speaks of waxen plums, and Ovid talks of “not only the black, but the nobler kind that borrow the hue of fresh wax.” Plums were grafted on to sloes, according to Virgil; in the garden of Horace plums grew on thorn trees. Columella knew three kinds of plums, and Pliny a number of varieties. The Roman name prunus came from the Greek prowmnon. With the tree and its fruit the name prunus spread from Italy to Central and Western Europe. Our English word “ bullace” is Celtic in origin, and sloe is the old Slavic sliva, aplum. In early times the two, Prunus insititia and P. domestica, were not clearly distinguished from each other. It is the first of these, I think, which, cultivated, produces the greengage. In the Mediterranean region plums have not the fine flavour of more northern districts. In Bosnia and Servia plums are cultivated most extensively. There whole forests of plum trees provide the chief food of the people for four or six weeks of the year. The fruit is dried and exported as far as America, pigs and plunis being the coin in which these people pay for their importations. Great quantities of this abundant fruit are made into plum brandy, mostly drunk on the spot. but also exported in considerable quantities. How long plum culture has been going on in the borderland of Austria and Turkey is unknown, but Herodotus alludes to the making of a drink fiom the berries in which North-east Europe is rich as an old Slavonian national trait. Prunus domestica is found wild in Anatolia, in’ the country south of the Caspian, and in Northern J Persia; P. insititia grows in a wild state in Cilicia, Armenia, south of the Caucasus, and in the province Talysch, near the Caspian. It seems probable, therefore, that these regions were the starting places whence plum trees have spread themselves more or less throughout Europe. From the time of Pliny old writers all relate how, after the destruction of the city of Cerasus, lying between Sinopé and Trapazunt on the Pontic coast, the Roman general, the rich Lucullus, trans- planted cherry trees from that region into Italy. Coming froma land of hard winters Prunus cerasus was able to spread itself through a country where P. avium seems to have been indigenous, so that 120 years after the transplanting by Lucullus the cherry tree was growing on the Rhine, in Belgium, and in Britain. In the Alps and northwards the cherry is better flavoured than near the Mediter- ranean. ‘To-day the Tyrol, Switzerland, and Upper Rhine are regions where the fruit thrives, and from the surplus harvest thereof in Switzerland is made the well-known cherry brandy, or ‘‘ Kirschwasser.” The original home of P. cerasus seems undeter- mined. All cultivated cherries come from two species, P. cerasus and P. avium, the geane The latter is wild in many places—Asia, north of Persia, Armenia, south of the Caspian, south of Russia, and in Europe generally from the south of Sweden to Greece, Italy, and Spain; also in Algeria. This gean, P. avium, was spread through Europe in prehistoric times, and must have been in Italy before Lucullus transplanted P. cerasus from Pontus. As cherry gets its name from a place, Cerasus, whence a good variety at least was brought, so the peach and apricot, in their names Prunus persica and P. armeniaca, show clearly whence they came. Coming from farther east than the cherry, their fruits later reached Italy. It was only in the middle of the first century of our era, when the Roman Empire came in touch with Armenia and the south shore of the Caspian, that the trees bearing them were brought to Italy, and gardeners asked high prices for the so-called Persian apples and Armenian plums. The almond, Prunus amygdalus, was brought from Pontus, in Asia Minor, first to Athens, where it went by the name amygdalé; later to Italy, where about 150 B.c. Cato called it nux Graeca. A medical book of the early first century A.D. mentions sweet and bitter almonds; and from that time the trees seem to have become almost as common in Italy as they are to-day, when in January, February, or March, as the season is mild or otherwise, gardens are white with the blossoms that come before the leaves. The cherry laurel, Prunus lauro-cerasus, the evergreen of our gardens, from the Levant, pro- duces, when it ripens here, most delicious fruit, as I know, having eaten it cooked during one of the hot summers when it abounded. M 2 324 Prunus padus, the- bird-cherry, is a northern ‘tree, native to Arctic Europe and Siberia, abound- ing in the north of our island, but not found wild in the south. Its graceful long racemes of flowers come with the new leaves, and the blooming of this bird-cherry, like that of the wild cherry, is ‘one of the events of our northern spring. OUR SCIENCE-GOSSTP. The north temperate zone appears to be the home of the genus Prunus, which consists there of some seventy-five species. ‘There are some few others in the tropics, but not more, I think, than half a dozen. Ambluside, February 1902. COCKROACHES, By E. J. BURGESS SOPP, F.R.Met.Soc., F.E.S. (Continued from page 297.) UR next division contains those insects that are truly indigenous to our islands. Omitting Phyllodromia germanica Stephens(??) had seven species—viz., Blatta pallens, B. perspicillaris, B. panzeri, B. nigripes, B. livida, B. pallida, and B. lapponum ; but later authorities have considerably curtailed this list, so that to-day we regard three only as undoubtedly native to Great Britain. They are all small and comparatively insignificant, and are included in the single genus Hetobia. Although Hetobia lapponum Linn. (fig. 5) often enters houses in many parts of Europe it is not recorded as having done so in England. It is known from the folowing two by having the head and antennae black and the disc of the pronotum always dark ; it may also be “ readily distinguished from panzeri by its larger size” (Burr), from livida by its darker colour, ‘The elytra, which are testa- ceous with darker markings and spots, are fully developed in the male, but in the female do not reach to the middle of the abdomen. Its size, according to the compiler of the “ Natural History of Insects,’ published at Perth in 1792, is ‘not much larger than a fly,” but as flies differ some- what in this respect it might be as well to add that the usual dimensions vary from about three- eighths to seven-sixteenths of an inch (9-11 mm.) in length in the male, the female being somewhat smaller. Unlike the majority of the family this insect can stand severe cold, and although nearly all our records are from the South of England there seems no reason, considering its far range in Scandinavia, why it should not ultimately be discovered further north. This is the species of which Linnaeus wrote that it occasionally attacked the Laplanders’ stocks of dried fish. Mr. Burr states the insects are found during summer amongst dried leaves and nettles, under moss, and in similar situations. I believe the species also occurred at “sugar” to Mr. Milton at Brockenhurst during 1899. My specimens are from Bootle, in Lancashire, where it would probably have been imported amongst: timber, the bulk of the foreign timber trade of the port of Liverpool being con- (27) “Tilus, of Brit. Entom.”; Kirby and Spence, “ Intro, to Brit. Entom,” fined to the North Docks, which extend into the former township. E. panzeri Steph. (fig. 9), the smallest of our British Blattidae, is of a lighter or darker testaceous hue, the male measuring but five-sixteenths of an inch (7-8 mm.) in length, and the female rather less. Apart from its average smaller size, it can usually be easily separated from the preceding cockroach by the paler disc of the shield and by having the vertex of the head light. The dotted wing-cases of the male are lanceolate in form and longer than the body, those of the female abruptly squared behind, as in the last species, but rather shorter. Pronotum with brown markings; legs dark brown or testaceous ; cerci dark. EL. panzeri is usually met with in sandy situa- tions, often frequenting the neighbourhood of the Aeolian dunes that form so characteristic a feature of much of our coast-line. It does not, apparently, occur much north of the Thames Valley, most of our records being from the southern counties of England. Mr. Burr (28) mentions it as common in ' Belgium, Holland, and France, and of occasional occurrence in Germany, Dalmatia, Ferrol, etc. My own specimens: come from the coast near Col- chester and from Branksome Park, Bournemouth, from which latter locality my friend Mr. Brockton Tomlin has also sent me the larvae. These are very distinct little creatures, having the pro- and meso-notum effectively decorated with a dark triangular figure. A variety of this insect, Mctobia panzert var. nigripes, occasionally occurs. It is considerably darker than the type and has black legs. Mr. Burr records it from the New Forest, Devonshire, and Bournemouth, from which last- named locality my own specimens also come. Our remaining indigenous cockroach, Zetobia livida Fabr. (fig. 10), barely exceeds five-sixteenths of an inch (8 mm.) in length. Its general hue is lighter than that of the two preceding species, and it still further differs from them in having the legs and cerci pale, the wings and elytra fully developed in both sexes and reaching beyond the end of the body. When there is any difference in ‘the alar organs of the cockroaches it is always the (28) ** Entomologist’s Record,” vol, xii. No. 8 (1900), SCIENCE-GOSSIP. males that have them most fully developed. ‘This little insect is usually taken by sweeping, or amongst leaves, etc., although it has also occurred by beating fir and oak at Broadwater Forest. Mr. Burr records it as widely distributed over Central and Southern Europe, it being, however, commoner 11. Blatta (Stilopuga) orientalis Linn., female, 13. Blabera gigantea Linn., showing underside of cockroach, The lower figure exhibits arrangement of ova in an opened egg-purse, half the Linn, 325 Mr. W. E. Sharp obtained it by sweeping in June 1900. é In our final group are included those cock- roaches, three in number, that are found from time to time in our seaports, markets, etc.—insects which, although only occasional visitants,. we can orientalis Tinn,, male. 14. Odtheca of B. orientalis 12. B. number of eggs being exposed to view. 15. Young nymph, B. orientalis Linn. 16. Older nymph, exhibiting the prolongation of lateral margins of thoracic segments, or gradual growth of wings. of B. orientalis Linn. in the south than towards the northern limits of its range. Amongst his British localities are the New and Charlton Forests, Dorking, Bournemouth, Woking, Bognor, Itchenor, etc., whilst I have also received it from Branksome, near Bournemouth ; Ferndown, Dorset; Tunbridge Wells, and Headley Lane, near Dorking, in Surrey, where my friend 17. First five joints of antennae of male (gf) and female (2) (Drawn by E. J. B. Sopp.) ill afford to omit. The section contains one of the Goliaths of the race, and many there be who will rejoice that it is of rare occurrence in the land. Rhyparobia maderae Fabr. (fig. 3) is a large and robust cockroach, measuring from one and three- eighths to over one and a half inches (85-39 mm.) in length, the broad oval elytra, which reach beyond 326 SCIENCE-GOSSTIP. the apex of the abdomen, serving to give the appearance of still more formidable dimensions. The general colour of the upper surface is lightish- ‘brown with darker markings, the dividing vein on the elytra being very distinct. The size of this handsome insect would alone prevent its being mistaken for either of the above-mentioned cock- roaches, it being not only longer but of a generally much stouter build than Periplaneta americana, the only one at all approaching it i size, My own representative is from the Gaboon (or Gabun) district of West Africa, where the species is very abundant, but the insect has occasionally been taken alive in and about the docks and markets of London. Leucophaea surinamensis Linn. (fig. 4) is a much smaller cockroach than our last, although ap- parently varying considerably in size, one of my specimens scarcely attaining to nine-sixteenths of an inch (15 mm.) in length, whilst another from St. Paul’s measures 24 mm., or very little short of aninch. The elytra are dark testaceous, the pro- notum being shining black and narrowly but dis- tinctly bordered with orange along its anterior margin, thus imparting a very pleasing effect to the upper surface of this attractive little insect. The elytra are fully developed in both sexes and reach slightly beyond the apex of the abdomen. Upper surface of body brown with yellow mark- ings; legs brown. L. surinamensis 1s a cosmopolitan cockroach, having spread with trade from its former haunts to various parts of the globe. It has very rarely occurred in Britain. Mr. Burr, however, records it from Bognor, where two were taken a few years ago by Mr. H. L. F. Guermonprez, who was of opinion they had been imported amongst bananas from Madeira, and one has since occurred at Kew. The claim of this tropical insect to be included in our lists thus rests on very slender grounds. The last, but by no means the least, of our occa- sional visitants is the Titan Blabera gigantca Linn. (fig. 13), which has often been captured in Britain. This handsome hexapod attains from nearly two and a quarter to two and three-quarter inches in extreme length; the genus Alabera, including amongst its many species the largest cockroaches at- present known(*). Its upper surface is light testaceous with a well-marked dark central patch on the disc of the shield, two dark patches on the left elytron, and one on the right. The elytra are of considerable breadth, and altogether the size of this insect serves to at once distinguish it from all our other species. ‘This is the ‘** Drummer” (*) of South America and the West Indies, so called from the fact of its being supposed by natives and others (29) The smallest members of the family, measuring less than the eighth of an inch, belong to the Genus Woctilwca, and were discovered by M. Simon a few years ago in cases in the Philip- pines (Camb. Nat. Hist.,” vol. v.) (30) Drury’s “ Insects,” iii. Preface. to make a sharp rapping sound during the night- time in the old wooden houses where it swarms in various parts. Cases are recorded in which it has been known to attack dead and even dying persons by nibbling their extremities. B. gigantea has been taken not uncommonly along the London docks, as well as at Bradford, Huddersfield, and one or two other places. For my * British ” specimen of this handsome insect I am indebted to my friend Mr. Willoughby Gardner. who received it some years ago from the Liverpool] docks. (To be concluded.) RUBBLE DRIFT AND DRY CHALK VALLEYS. By Epwarp A. Martin, F.G:S. RESTWICH was one of the earliest geologists to recognise that, beside the various sub- aérial, marine, and river-valley drifts, there was a fourth that he designated the “rubble drift,” and which he first recognised in 1851 in the Sangatte Cliff. This has also long been known under the general term of “head,” and it is this which is associated with all the raised beaches around our coasts. ‘These raised beaches are all fairly uniform in structure, containing rounded local and foreign stones, but the rubble drift naturally varies in composition according to locality, and as to whether it has been formed near or far from the source of its constituent parts. The raised beaches were probably continuous around all our southern coasts ; but the contour of the coast being different at the time of formation from that which now obtains, the encroachments of the sea have very widely destroyed all traces of them. ‘The rubble drift, which in some places occurs immediately over the raised beach, as at Kemp Town, Brighton, can also be seen at the following places, in many cases, however, without any beach, as though it were more extensive in its formation than the latter:—Margate, South- Eastern railway station; .the gaps on each side of the North Foreland; the cliffs west of Rams- gate; South Foreland, by Kingsdown ; Dover West Cliff, where mammoth remains have been found ; Folkestone, under the Battery, with hippopotamus and mammoth remains; under Eastbourne, again with remains of hippopotamus and mammoth : Birlng Gap; Cuckmere Valley; Ouse Valley, above Newhaven, with bones of a species of Hlephas; Rottingdean ; Brighton, at Kemp own, including mammoth and hippopotamus ; Hove and Portslade; the Sussex Coast plain, at Worthing, Peppering, and Selsey, and especially near Chi- chester, where were mammoth remains ; Hayling Island; Portsea; Bembridge Point, Isle of Wight ; Freshwater Gate, inammoth being represented ; SCIENCE-GOSSIP. 327 Isle of Portland; Chesilton; Dawlish; Hope’s Nose, Torquay ; many occurrences on south and north coasts of Devon and Cornwall; and Porlock Bay, where are found remains of a submarine forest. Prestwich was unable to support Godwin Austen’s theory, which was supported by Lyell, that the large palaeozoic and crystalline boulders found in the raised beaches and in the bed of the Channel had travelled along an old coast-line extending between Normandy and Sussex. At present the tidal movements carry pebbly beach up channel west to east; but the presence of chalk flints in the Devon raised beaches indicates that the move- ment of materials was from east to west at the time of their formation. The Ramsgate fishermen are constantly meeting with obstacles to their trawling in the shape of granite and serpentine blocks that strew the bed of the ocean. Prestwich, therefore, concluded that such foreign blocks were brought through the open Straits of Dover in the arms of floes and bergs by a current from the North Sea. Such ice-floes especially became stranded in the bay that stretched from the west coast of Sussex across to Bembridge. Clement Reid has pointed out how great was the deposition of these foreign blocks in this particular area, the Solent River then being perhaps in existence, but the strait of Spithead not yet having been formed. It seemed most probable that the foreign boulders of the raised beaches were derived from the “crystalline, metamorphic, and palaeozoic rocks of Norway,” or some of them possibly came from Germany and the Ardennes. The raised beaches may be regarded with tolerable certainty as contemporaneous with the lowest of the river drifts of the Thames and Somme Valleys, also with the fauna of the cave epoch, and these are but little removed in time from recent alluvial beds. The rubble or head, which contains mammoth remains, is therefore, accord- ing to this chronology, more recent than the latest valley drifts. Certain drifts in the London basin, which Mr. Whitaker places under “ Doubtful Deposits,” have “the appearance of a*iocal wash,” and many of these drifts Prestwich places with the “head,” so far as the cause of them is concerned. The character of the head depends entirely upon the character of the local strata, and the fragments of the harder portions of which it is composed are sharp and angular. It follows the slopes of the hills, and as it recedes from its base becomes sub- angular. As it ranges from the chalk hills the chalky element gradually disappears. The mass takes the colour and composition of a tertiary loam or brick earth. The fact that it contains the remains of land shells and land animals forms a sure guide in tracing the same formation inland or elsewhere. Murchison called it the angular flint drift, and considered it to have been caused by great waves of translation resulting from the sudden elevation and breaking up of the Wealden area by earthquake action; but geologists do not now appeal to catastrophic action as an explanation of the de- nudation of the Weald. Lyell considered that the head as it appears at Brighton “ might have been heaped up above the sea-level in the delta of a river draining a region of white chalk,” with perhaps a slow subsidence during accumulation. He thought that the large blocks and angular flints might have been trans- ported by the aid of ice, the river and its tribu- taries being occasionally frozen over. This seems the most reasonable explanation of ‘* head.” Mr. Clement Reid calls in the aid of a frozen climate in order to explain the origin of - the numerous and now waterless chalk valleys. With the ground frozen in a winter of Arctic severity to a depth of several hundred feet, the otherwise permeable chalk would be rendered impermeable to the summer rains, and the surface waters then, according to Reid, carried down the angular chalky debris which went to form the local coombe rock in the valleys and “ head.” Prestwich thought that after the formation of the raised beaches the land was temporarily raised 100 to 120 feet, and the sand dunes, which occasionally occur between the raised beach and: the head, were formed. ‘Then camea submergence of about 1,000 feet. Much of the blown sand was denuded away, but the submergence did not last long enough for the establishment of a marine fauna. On the final uprise of the land which followed, the deposition of the rubble drift com- menced, being caused by the displacement from a state of rest of a great body of water. In order that the resulting formation, the head, should be in any way different from other deposits, I under- stand Prestwich to mean that the rise was sudden and the resulting wave-action was of a cataclysmic nature. This without ice would no doubt be sufficient to transport the trail of debris over the West Sussex plain, with but a slight fall in the surface. Clement Reid has extended the application of his theory of the formation of frozen-soil gravels to the gravels of the Thames Valley. These terrace gravels, which we are accustomed to regard as marking successive stages in the excava- tion of the Thames Valley by the river, may, he thinks, have after all been laid down contempo- raneously at all heights, the determination of the relative ages of such gravels by reference to heights above Ordnance data being of no value whatever. He believes that there were two distinct periods of Arctic cold, as evidenced in the south and east of England, and these were divided. by a mild episode when the characteristic Pleistocene mammalian and molluscan fauna inhabited this country. The second glaciation not reaching south of the Wash, the rain in non-glaciated areas 328 SCIENCE-GOSSIP. fell on the frozen soil, and thus led to extensive sheets of gravel. Let us put Prestwich, Lyell, and Clement Reid into the melting-pot and adopt something from each. As one who has been familiar with the dry Sussex coombes for many years, I may perhaps express an opinion as to their mode of excavation and the formation of rubble drift. First of all, the dry coombes must have been caused by water action. Everybody is so far agreed. It is also allowed that the water must have been in motion. The coombes emerge towards the sea with but few exceptions ; therefore the moving water must have excavated and moved southwards. The Weald may have been covered with its beds continuously from north to south. If so, the coombes which then existed had not been denuded sufticiently deeply to cut down below the level of the highest part of the existing downs, except perhaps where now are the gaps at Lewes, Devil’s Dyke, Saddles- comb, and the southerly flowing rivers now exist- ing. Surely, however, the carving of these valleys would commence long before the chalk finally protruded its head out of the sea at the close of its last period of submergence. I think with each change of level, as the bed of the sea approached the surface, there would be a perfect tumult of currents, and the more rapid the rise the more complicated and unsettled would be the courses taken by such currents. As the land emerged, which we all admit it did finally, however we may disagree on other points, the marine currents would subside, but would in some cases be replaced by fresh-water streams, or even torrents, owing to the saturation of the chalk beneath. I cannot account for the absence of marine shells in the valleys, but they may have all been decomposed during the ‘“pluvial” period, a process which, indeed, goes on over the Downs in the case of dead land shells even now. The marine-shell question need not trouble us. They are not found here on the Downs, yet no one ventures to say that the chalk was not, all of it, under the sea at some time or other, in Quaternary times. Up some of the valleys formed under the sea, the tides would still act and erode. Nothing is more porous than a beach of rounded flints. Yet the tides breaking on the Brighton beach now form miniature hollow coombes with rounded heights between, like, indeed, to downs in miniature. There the sea does the work. although in an instant it has sunk through the porous beach. Where is the necessity to argue for a frozen soil? Repeated tides will often flow through just the same’ miniature ““coombes” over and over again, and these will not necessarily be parallel to one another. Another point, too: the coombes which they make are gene- rally clear of detrital matter, which in their case is carried away to form a “rubble drift,” perhaps beyond low tide, with mammalian remains, occa- sionally in the shape of a dead dog or cat. As the tides finally retired and the “pluvial” period ceased most of the coombes would be run dry, the rainfall being not greater than could be assimilated by the porous chalk. That marine shells are absent is true. If not explicable, as suggested above, it cannot be denied that they may yet be found. A point in favour of this theory is the fact that in some of the chalk rubbles there are found land shells, for in such cases we should have the waves. of retiring tides drawing denizens of the land into the sea and actually depositing rubble strata con- taining land shells. Where ‘“ head” has been formed to any large extent there must have been, after the retiring sea had done its work, a com- paratively large river in existence. In the case of the Brighton ‘‘ head” there were two rivers which joined before the cliffs were reached. If, as geologists believe, the Weald was denuded during the course of an upheaval or upheavals over the central ridge, surely it is not assuming too much to believe that, after another submergence and another upheaval, that part of the Downs that remained and was nearest the Weald continued to uprise over and above the degree to which the existing coast was raised. In that case the angle of the fall of torrential waters would possibly be sufficient, with the occasional aid of ice-floes, to deposit the head containing flints, angular because of the shortness of their journeys, together with Ter- tiary sandstones, with their rough corners rounded. It may be that some gravel has been formed in the way brought forward by Mr. Clement Reid. The great fault, however, with modern gravel geologists is to ‘overburden the boat,” to ride their own particular theories to the death by endeavouring to cause them to explain too much, ‘or, as in the case of Prestwich, by classing too many different deposits together under one name. The most sensible view of rubble deposits seems to be that of Mr. J. Allen Brown, who claimed that these had been formed at all times since the last period of emergence. He also, very reasonably as I think, attributed the formation of much of the angular gravel to the removing action of subter- ranean waters upon the- éhalk, the latter being removed both in solution and mechanically. See also Whitaker’s ‘« Guide to the Geology of London,” ed. 1901, p. 72, concerning the formation of “ clay with flints.” Given a pluvial period, a period of floods, there seems no reason why Lyell should not, after all, prove to be correct in recognising, in some of the rubble drifts of Sussex at least, the deltaic work of rivers piercing the Downs, in this way doing away with the necessity of imagining a sub- mergence of the land here to at least 1,000 feet (Prestwich), the height of the highest occurrence of such drift elsewhere. 23 Campbell Toad, Croydon, Mareh 1902. SCIENCE-GOSSTIP. ill BARGAINS IN SCIENTIFIC BOOKS COLE (A.C.). METHODS OF MICRO- SCOPICAL RESEARCH: a Practical Guide to Micro- scopical Manipulation. 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With 14 Plates and 42 Illustrations in the Text. THE FORAMINIFERA. AN INTRODUCTION TO THE STUDY OF THE PROTOZOA. By FREDERICK CHAPMAN, A.L.S., F.R.M.S., Formerly Assistant in the Geological Laboratory of the Royal College of Science, London; Palzontologist to the National Museum, Melbourne. LONGMANS, GREEN & CO., London, New York & Bombay. SECOND-HAND BOOKS. JOHN WHELDON & CO., 38 GREAT QUEEN STREET, LONDON, W.C. can supply most Books in the various branches of NATURAL HISTORY AND SCIENCE in good condition at moderate prices. STATE WANTS, OR CATALOGUE SENT POST FREE. SCIENCE-GOSS/P. Revolutionising Photography. -HORNTON : CADETT ) SPECTRUM) |} tex: ICKARD AND SHUTTERS Make Photography a Pleasure. ** AMBER’ and ‘‘RUBY”’ Cameras for Hand or Stand. Price from £42 3s. Gd. Time and Instantaneous Shutter, from 12s. 6d. Standard Pattern, “2 2 fromslsemGde { TWO PTA TE: (BRANDS = —— Yt, = (i a AND LIGHT FILTERS. ||| 9 Write for Booklet ‘‘Orthochromatic Photography” Gratis. Post Free. 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Pyice List, 2d. 300 Lecture Sets of Science Subjects and Travels, &c¢. 60,000 Slides; List, Sd. Post Free. so beautifully coloured Slides loaned for 3S. By Subscription for the eh 450 10s. 6d. : 1,000 21s. Hire List, 24d. ee ada Ww. CGC. ELUOUGHES, Specialist in Optical Projection. Established over 30 years. Brewster House, 82 Mortimer Road, Kingsland, LONDON, N. SCIENCE-GOSSIP. AN INTRODUCTION TO BRITISH 39) SPIDERS. By FRANK PERCY SMITH. (Continued from page 299.) FAMILY ZLYCOSIDAE. In this family the four posterior eyes are, as a rule, much larger than the four anterior, and form a quadrilateral figure upon the upper surface of the caput. We may in consequence refer to the eyes as being placed in three transverse rows of 4, 2, 2 The tarsal claws are three in number. The Lycosidae spin no snare, but hunt their prey upon the ground or low herbage, the term ‘‘ wolf- spider” being consequently applied to many of the representatives of this family. Some species are able to run upon the surface of water, these being commonly known as * raft-spiders. ” GENUS P/SAUGRA SIM. In this genus the eyes are not very greatly un- equal in size, and the second row is much shorter than the first. The clypeus is high. The legs are long and rather slender. The radial joint of the male palpus is provided with an apophysis. Pisaura mirabilis Clk. Bl., Ocyale mtrabilis Cb. Length. Male 10omm., emae 14 mm. This fine species is common in most parts of the country, running rapidly amongst low herbage. (Dolomedes mirabilis GENUS DOLOMEDES LATR. The spiders included in this genus are very similar to Prsaura. They are, however, of a far more robust form. The tarsi and metatarsi are pro- vided with scopulae. Dolomedes fimbriatus Walck. fimbriatus + D. ornatus in Britain and Ireland.”’) Length. Male 12 mm., female 20 mm. This handsome spider is almost invariably found in swamps and marshes, but is rather uncommon. ‘¢ Spiders of Great GENUS PIRATA SUND. Eyes of second row much larger than those of first row. Superior spinners decidedly longer than the inferior. Radial joint of male palpus without apophysis. : Pirata piscatoria Clk. Length. Male 9 mm., female 11 mm. Cephalo-thorax dull yellow-brown with dark lateral bands. These bands are furnished with a dense coating of brilliant white hairs. Rare. (Dolomedes Pirata piraticus (Lycosa piratica Bl.) Length. Male 5 mm., female 6 mm. Cephalo-thorax yellowish-brown with lateral, but not marginal, dark bands. A very common species. (Lycosa prscatoria: Pirata hygrophilus Thor. Bl.) Length. Male 6 mm., female 7 mm. 7 a ees Sens oe uy te lec ga Pisaura mirabilis. Clk. a. Profile of Female, legs and palp truncated; 4. Palpus of Male; c. Vulva; d. Eyes of Female, viewed from in front. Cephalo-thorax yellowish-brown with dark lateral and marginal bands. Common. Pirata latitans Bl. (Lycosa latitans Bl.) Length. Male 4 mm., female 5 mm. Cephalo-thorax dull dark-brown. Not rare. Pirata knorrii Scop. Length. Male 5 mm., female larger. Legs distinctly annulated. A very rare species. GENUS Z7ROCHOSA. The spiders included in this genus are, as a rule, larger and more robust than Pevata. The superior spinners are not longer than the inferior. The M 3 350 anterior row of eyes is never less than the second row. Trochosa ruricola Degeer. (Lycosa campestris Bl.) Length. Male 9 mm., female 13 mm. The palpus of the male is terminated by a short claw, and the fang of each falx has a small knob- like projection on its outer side. A very common species. Trochosa robusta Sim. Length. Male 10 mm., female 15 mm. May be distinguished in the male 7. ruricola by the absence of the projection upon sex from the fang. Very rare. Trochosa terricola Thor. (Zycosa agretyca Bl.) Length. Male 7 mm., female 12 mm. This species may be distinguished from the fore- going by the absence of the terminal claw of the male palpus. It is common. Trochosa spinipalpis F. Cb. Length. Male 8 mm., female 10 mm. The radial joint of the male is furnished with a number of stout spines towards its fore extremity on the inner side. Rare. Trochosa leopardus Sund. BI.) Length. Male 7 mm., female 9 mm. This species may be distinguished by the extremely narrow digital joint of the palpus of the male. Not common. (Lycosa cambrica Trochosa cinerea Fabr. (Lycosa allodroma Bl.) Length. Male 16 mm., female 17 mm. Allied to 7. deopardus, but easily distinguished by ceason of its large size. Trochosa picta Hahn. Length. Male 7 mm., female 8 mm. The digital joint of the male palpus is very narrow, but not so much so as 7. deofardus. It may be dis- tinguished from that species by the brilliantly coloured abdomen. It is not uncommon. ‘Trochosa biunguiculata Cb. Length. Male 8 mm. Digital joint terminated by two short claws. rare. Very GENUS ZARENTULA SUND. The spiders of this genus are not by any means sharply separated from Zyochosa. In the present case the anterior row of eyes is never longer, but is usually shorter than the second row. The clypeus, too, is usually higher than in Zyochosa. Tarentula pulverulenta Clk. Bl.) Length. (Lycosa rapax Male 6 mm., female 9 mm. SCIENCE-GOSSIP. Eyes of anterior row equally separated. This row is distinctly shorter than the second. Not uncommon. Tarentula cuneata Clk. Length. Male 6 mm., female § mm. Closely allied to 7. pulveriulenta, but the tibiae ot the anterior legs of the male are dark and swollen. Rare, Tarentula accentuata Latr. (Lycosa an- drenivora Bl.) Length. -Male 8 mm., female 9 mm. This species may be distinguished from 7. pzlveru- lenta by the distance between the anterior central eyes being greater than that between one of them and the adjacent lateral. Not uncommon. Tarentula fabrilis Clk. Length. Male 12 mm., female 15 mm. This spider may be at once recognised by its large size. The anterior central eyes are larger than the laterals, and the anterior row is almost as long as the second. 9.03 9. Sa PD egal -. Wenus* Oey. on Re 2.28 8. enn emmers .» Mercury*.. Gam, .. oy GS JESS Manlvatese tsp nen ars -.» Noon O06 3. eee Pe ONES Cerest 4ranms erie Sy ORB ISE mG tc -. Saturn 2AM eee ye BeOS * Daylight. + Below English horizon. OCCULTATIONS. Angle Angle Magni- Dis- from Re- Strom April Star. tude. appears. Vertex. appears. Vi ertem. him. 2 him. 11... 6° Tauri Ao DN cle Os5.0)D-WNy) fefenn Bod ars NWO ssa bl tae. 4:6 2.11.23 pm... 50.. 15... 68 Geminorum 5:0 ., 21-22 a Virginis 1:2 29... p' Sagittarii 10.15 pm. .. 193 Below horizon. 0:36am. .. 15.. 1. (9:asma 296 ..11.46 pm. .. 144 . 0.52a.m. .. 242 39... 4.20 a.m. . 5.. 6.44a,.m. .. 245 THE SUN. There is a very slight partial solar eclipse on April 8th, visible in far northern (arctic) regions in the early afternoon, but quite invisible at Greenwich. PARTIAL ECLIPSE OF ToraL EcCLIrpsk OF THE Moon. On April 22nd the moon rises at 7.5 p.m. totally eclipsed, about 12 minutes after the middle of the SCIENCE-GOSS/P. 347 eclipse. Totality ends at 7.35:-4 p.m., the last contact with the shadow occurs at 8.45°4 p.m., and with the penumbra at 9.55°3 p.m. The last contact with the shadow is at a point 60° from the north point towards the west. Dr. C Hillebrand calls attention to the fact that, owing to the effect of refraction, it may be possible, in suitable localities, to see the setting sun close to the western horizon and the eclipsed moon close to the eastern horizon at the eclipse of April 22nd; and on October 17th, the conditions will be reversed the ‘sun in the east and the eclipsed moon in the west. THE SUN, after a long state of inactivity, became very disturbed in the early days of March. In the north-eastern quadrant there was, upon the 6th, a group of large spots covering an oval area having apparently a mean diameter of not less than 43,000 miles. A more elongated group of small spots was visible in the north-western quadrant and a small group of faculae just within the south- eastern limb. On March 9th the area covered by the large group was found to be 86,600 miles by 43,000 ‘miles in extent. A watch should be kept for further outbreaks. MERCURY is a morning star all the month until April 29th, when it is in superior conjunction with the sun at lam. At midnight on the 23rd Mars and Mercury are in conjunction, the latter being only 40’ to the south. It is not in favourable position for observation. VENUS is amorning star all the month, reaching her greatest elongation west, 46° 12’, at midnight on April : 25th, on “which date it rises at 3.26 a.m., only an hour and 21 minutes before the sun. Its path is wholly through the constellation Aquarius. MARS is too near the Sun for observation. JUPITER and SATURN are morning stars all the month. Saturn rises at 3.9 am. on Ist and at 1.19 on 30th, Jupiter rising 40 and 50 minutes later respectively. URANUS retrogrades along a short path a little north of 44 Ophiuchi, situated a little N.E. of the star 6 in that constellation. NEPTUNE may still be observed in the evenings ‘on the borders of Taurus and Gemini. NEw MINOR PLANETS.—The discovery by Dr. ‘Carnera of five of these tiny bodies, one on February 12th, three on March 3rd, and one on March 4th, is announced from Professor Max Wolt’s Astro- . physical Observatory, K6nigstuhl, Heidelberg. ) “ON THE PHENOMENA CALLED SIGNALS ON Mars” was the title of a paper read by Mr. Percival Lowell at a meeting of the Astronomical and Astrophysical Society of America in December last. It referred to the bright projections seen upon Mars by Mr. A. E. Douglass on December 7th and 8th, 1900. They are ‘shown by subsequent calculation to have belonged to different parts of the planet. Apparently both were in motion, nearly due west, during the time of observation, and were probably due to clouds. BRILLIANT SUN PILLAR.—The evening of March 6th was beautified by one of these remark- able phenomena. It seems to have been first noticed by Mr. McHenry Corder, of Bridgewater, the well-known meteor observer, as early as five o’clock. At this time it was white, and there were slight. traces of a halo around the sun. Colonel H. E. Markwick at Devonport observed it at 5.50 about 20 m. before sunset. When first seen, nearly all observers agree that it appeared white, deepening in tint to golden, and finally crimson. After sun- set it appeared to rise from a low cloud bank, and. to have had an altitude of some 20°, gradually shortening. It seems to have disappeared about 6.40 p.m. To Mr. W. A. Knight at Bruton, Somer- set, a few light clouds, visible at the same time, appeared to pass behind the pillar. Messrs. Corder and Markwick both note the similarity of its ap- pearance to a comet. It was seen from London and Salisbury on the east, and at Penzance on the west. Its origin was terrestrial, the sun’s rays being refracted by ice crystals in the upper regions of the atmosphere. The phenomenon is quite different from the zodiacal light, with which some seem to have confused it. THE GREAT COMET OF 1901.—At the meeting of the British Astronomical Association on Febru- ary 26th Mr. E. Walter Maunder called attention to the memoir by Professor Brédikhine, Director of the Pulkowa Observatory, on the shape of this comet’s tail. This worker many years since made an especial study of cometary tails, with the result that he divided tails into three groups. First type, long and straight, like the tail of great comet of 1861. Second type, the long curved plume, like that of Donati’s comet of 1858. The third type, by no means frequently found, where the tails are short and violently curved. These different types are supposed to be caused by the varying molecular weights of the gas or vapour composing them, and therefore of its susceptibility to the unknown repulsive force which forms them. The first comet of the present century, previously to its perihelion passage, showed but a single tail, and that of the first type. After perihelion it exhibited two tails, one of the second and one of the third type. A study of the last-mentioned seems to indicate that it was originated by a great explosion which must have taken place on April 22nd. The second-type tail was somewhat different from those usually ob- served, in that the central rift was not of the usual conoidal form, but instead conical, having the nucleus at its apex. This is well shown on photo- eraphs dated May 5th and May 20th, on which, as also on that of April 24th, the nucleus appear ed to have no envelopes on the side towards the Sun. The third-type tail also differed from those usually seen in that form. Instead of being short, it had a length of from 30° to 40° longer than the principal tail. The drawings and photographs from which the Professor drew his conclusions were principally those made at the Royal Observatory, Cape of Good Hope. GREAT METEOR.—On the evening of January 7th, at 8.35 Sydney mean time, a very brilliant meteor was observed in New South Wales, at places so far as 370 miles apart. It appears to have radiated from a point in the constellation Octans about R.A. 16 h. Dec. 8. 83°, and during visibility fell from a height of 71 miles to that of 28 miles. Its path must have had a length of about 100 miles, which was traversed in about three seconds. A few minutes after its disappearance a terrific ex- plosion was heard, which in some places was so violent as to shake windows and even cause build- ings to vibrate. These particulars are gleaned from a paper read by Mr. W. E. Besley before the British Astronomical Association. Ene Oe — a se ye eS CONDUCTED BY C. AINSWORTH MITCHELL, B.A.OXON., F.I.C., F.C.8. BREATHING UNDER WATER.—Some years ago a diver’s helmet was constructed by Mr. Fleuss with the object of enabling the divers to be independent of an external supply of air. In this apparatus the exhaled carbon dioxide is absorbed by caustic potash, whilst the oxygen consumed is replaced by fresh gas from a small portable cylinder com- municating with the helmet. The efficacy of this appliance has been frequently demonstrated by Mr. Fleuss, but never in a more striking manner than when he passed through the flooded Severn tunnel, remaining under water for more than thirty minutes. The helmet has also been adapted for the use of firemen, who by its aid are enabled to breathe in an atmosphere of thick smoke. A simpler apparatus on the same lines has recently been devised by Drs. Desgrez and Balthazar, of Paris. The main feature of their invention is the use of sodium peroxide, which was discovered in 1862 by Professor Vernon Harcourt, though it has been but little used, except as a reagent in analytical chemistry, Commercial sodium peroxide is a yellowish-white powder, which is extremely caustic and possesses strong oxidising properties. On exposure to the air it absorbs carbon dioxide in the same way as caustic soda, being converted into carbonate, whilst on treatment with water it is decomposed into caustic soda and gaseous oxygen. ‘Thus on placing sodium peroxide in con- tact with water in an atmosphere that is being breathed, the carbon dioxide will be continually absorbed and the oxygen renewed by one and the same substance. The apparatus applying this principle contains a clockwork appliance by means of which sodium peroxide is made to fall at regular intervals to water, whilst the violence of the reac- tion is moderated by a refrigerator. The apparatus is contained in a light circular box of aluminium, and is connected with the helmet by means of two rubber tubes. With the aid of this “oxygen generator ” Dr. Balthazar has been able to remain for more than half an hour in an atmosphere saturated with sulphurous acid. ARTIFICIAL PARTHENOGENESIS. —Greeley has discovered the interesting fact that it is possible S effect the development of the mature unfertilised eggs of the starfish by exposing them in sea-water to a temperature of 4° to 7° C. for one to nine hours. Another striking fact in this connection is the influence of potassium cyanide in prolonging the life of the unfertilised eges of the sea-urchin, which has recently been demonstrated by Loeb and Lewis. It was found that this salt, which is ordinarily such a deadly poison, when added in a small proportion to the sea-water apparently effected a suspension of the processes which cause the death of the unfertilised eggs. Possibly these processes are of an enzymic character presenting an analogy to the so-called fibrine fer ment, which SCIENCE-GOSSTP is said to be the agent causing the coagulation of the blood. It has frequently been shown that potassium cyanide has a restrictive influence on the action of various enzymes. “RED” Cop.—Minute red points resembling vermilion have occasionally been observed on dried salt cod, and in 1887 a whole cargo of fish at Lerwick was thus infected. Dr. Edington found the phenomenon was due to a micro-organism,. Bacillus rubescens, which developed not only on the fish, but also on the salt used by the curers. When grown upon nutrient gelatin a wrinkled colony was formed, in which a pink colour only developed after some weeks. Though this micro- organism was proved to be harmless, the fact of its being present at all showed that the fish were insufficiently preserved, and might thus become a suitable medium for the development of pathogenic bacteria; and as a matter of fact several other species of non-pathogenic micro-organisms were isolated by Dr. Edington, although that mentioned above was the only one that produced a colouring matter. This bacillus is quite distinct from B. pro- digiosus, which forms a blood-red colony on moist bread, and occasionally on meat. Dantec sub- sequently found two chromogenic micro-organisms, a bacillus forming terminal spores and a micro- coccus, which produced a red pigment when grown upon gelatin, but formed colourless colonies when cultivated by itself upon salt cod. ACTION OF DISTILLED WATER ON LEAD.—Pro- fessor Clowes. has made a series of experiments to determine the influence of various salts and gases upon the solvent action of water upon lead. From the results obtained it is evident that carbon dioxide has a restrictive influence, which is greater in proportion to its quantity, whilst free oxygen is the principal active agent. It was also found that of the substances that prevent the solvent action the most effective were sulphuric acid and sul- phates, while lime (calcium hydroxide) was much less effective, and when present in large quantities even promoted the action. Distilled water, free from dissolved gases, only dissolved lead to the extent of 0°3 part per million when kept out of contact. with atmospheric oxygen. The amounts of lead dissolved by the water in the presence of oxygen and carbon dioxide were as follows :— | 48 hours | 7 | — | 24 hours 72 hours | \i= a | Sao =) =, = |= ae Per cent. | Per cent. | Per cent. Oxygen alone 50 Se 0-013 0:023 0:029 Carbon dioxide alone 0:005 0-008 0:017 Oxygen and Carbon dioxide ; | in equal volumes 0°:003 0°003 0°603 | Oxygen and Carbon dioxide | (Bei) aes ae Be 0015 =| 0-018 —— | | COMPOSITION OF ANTIQUE STATUETTES.—An interesting communication by M. Ber thelot in a recent issue of the ‘‘Comptes Rendus” shows that the Chaldeans and Babylonians were possessed of considerable metallurgical skill. A Babylonian statuette was found to consist of a copper alloy containing 79:5 per cent. of copper, 1°25 per cent. of tin, and 08 per cent. of iron. A similar statuette from Chaldea estimated to be 2,200 years old was composed of nearly pure copper containing only a slight proportion of iron, whereas another Chaldean statuette, some 400 years older, consisted mainly of an alloy of four parts of copper with one part of lead and a trace of sulphur. SCIENCE-GOSSTIP. ( >s SSS SS SS CONTRIBUTED BY W. H. CADMAN. LORD KELVIN.—We are glad to notice the name of this great physicist included in the modest list of nine distinguished men upon whom the young University of Wales will confer in May the degree of Doctor in Legibus (honoris causa), in celebrating the second installation of a Royal Chancellor. EFFECT OF SMOKE AND GAS UPON VEGETA- TION.—The extent of injury to agricultural and forestry interests by pollution of the atmosphere in cokeing and other manufacturing operations has received considerable attention during the last few years. W. A. Buckhout has recently noted the condition of vegetation in the immediate vicinity of a number of manufacturing centres in America. The injurious effect of the gases, smoke, and soot is shown by the destruction of forests and orchards in the vicinity of large manu- facturing establishments. The most: practicable method for the prevention of some of this injury is believed to be the erection of tall smoke stacks or chimneys, in order to secure the most effectual aid in rapid dilution of the gases. Much mischief would be prevented if such works were erected in large open plains instead of in valleys, as is so often the case. INFLUENCE OF MOUNTAINS ON HAILSTORMS.— This disputed subject has received much attention at the hands of the Italian Meteorological Office. In the last publication Professor V. Monti compares the results of observations for seven years at the typical stations, the Collegio Romano, and Monte- cavo, an isolated station at an altitude of 1,000 metres, near Rome. Highty days of hail were observed at Montecavo against forty-one at Rome. During the same period there were 176 thunder- storms at Rome, compared with 129 at the other station. The excess of hail at the mountain station does not appear to be attributable to a greater intensity of atmospheric electricity. ‘The monthly mean temperature at Rome is about 10° C. higher than at Montecavo, and hence Professor Monti suggests that the fusion of hail in crossing the warmer stratum of air may account for the smaller amount at the lower station. MATHEMATICAL INVESTIGATION OF INTEL- LECTUAL ABILITY.—The “Proceedings of the Royal Society,” No. 456, March 7th, 1902, contain an amusing article on ‘‘The Correlation of Intel- lectual Ability with the Size and Shape of the Head,” drawn up by Karl Pearson, F.R.S. Miss M. Beeton, of Girton College, prepared cards giving the name, college, and chief physical measurements of upwards of a thousand Cam- bridge undergraduates. The nature of the degrees ultimately obtained by them were then compared with these measurements. ‘Tables are given show- ing the relation between ability and length and breadth of the heads of different men. The author finally concludes that “very brilliant men 349 may possibly have a very slightly larger head than their fellows; but, taking the general popu- lation, there is really a very insignificant associa- tion between size of head and ability. For practical purposes it seems impossible to pass any judgment from size of head to ability, or vice versa.” RATE OF RECOMBINATION OF IONS IN GASES UNDER DIFFERENT PRESSURES.—‘‘ The London, Edinburgh, and Dublin Phil. Mag.” for March 1902 contains an interesting paper on this subject by R. K. McClung, M.A. Any gas which has been exposed to Réntgen rays retains the ionisation thus produced for a short time after the source of radiation has been removed. The negative and positive ions take an appreciable time to recom- bine with each other. This question of the rate of recombination of ions was investigated by Pro- fessor Rutherford for air and some other gases at atmospheric pressure. McClung undertook his research to find the relation between the rates of recombination at different pressures. The rays from an X-ray bulb passed through a brass cylinder containing the electrodes consisting of thin aluminium foil between which the leak was mea- sured. ‘he cylinder was made so that it might be exhausted or subjected to considerable internal pressure as desired. The results obtained show that the rate at which the ions recombine in ionised air is determined by the same law, no matter what the pressure may be—namely, a — an’, where 7 is the number of ions per c.c. in the gas at any time, ¢, after the rays have ceased, and aisa constant for any given gas. The same law was found to hold true for hydrogen and carbon dioxide as for air. ELEctRIC DETONATORS.—It is not, perhaps, generally understood how useless dynamite and other high explosives would be except for the insignificant little detonator. A ton of dynamite may lie secure, yet the smallest Nobel detonator exploded in the mass sets free the terrible resist- less power of the dynamite in all its fury. Detonators consist of thin copper tubes closed at one end and filled with a detonating composition consisting of fulminate of mercury and, generally, potassium chlorate. Fulminate of mercury is pro- duced by the action of nitric acid and alcohol upon mercury. It is very sensitive to heat and shock, and, being one of the quickest explosives known, gives an extremely sharp shock, which is exactly what is required to detonate dynamite. Electric detonators usually contain a mixture of antimony sulphide and potassium chlorate as a priming mixture, in addition to the fulminate of mercury. There are two systems of electrical blasting—namely, high tension and low tension. The high-tension E.D. fuses are largely used in Europe. Attached to the ends of the wires em- bedded in the detonator is a sensitive chemical composition which is ignited by a spark passing between the terminals, resulting in an explosion. Low-tension E.D. fuses have within the detonator a fine platinum wire encased in a suitable flashing mixture; and this wire on becoming heated by the current ignites the mixture, which in its turn explodes the detonator. This system is in almost universal use in tropical countries. The low-ten- sion possess a great advantage over high-tension fuses, in that their efficiency can be tested at any time with a galvanometer. SCIENCE-GOSSTIP. CONDUCTED BY B. FOULKES-WINKS, M.R.P.S. EXPOSURE TABLE FOR APRIL. The figures in the following table are worked out for plates of about 100 Hurter & Driffield. For plates of lower speed number give more exposure in proportion. Thus platesof 50 H. & D. would require just double the exposure. In the same way, plates of a higher speed number will require proportionately less exposure. Time, 10 a.m. to 2 p.m. Between 9 and 10 a.m. and 2 and 3 p.m. double the required exposure. Between 8 and 9 a.m. and 3 and 4 p.m. alae by 4. Scenes, and Groups SUBJECT F, 5°6) F. 8 | F. u |F. 16| F.22 iF. 32 | F.45)| F. 64 | | | | SeaandSky.. | sts |a25 ado | & | & | & | 2 1 | | | | |Open Landscape. ) and Shipping "a| = | sv | ve | 3 2 3 : | Landscape,with dark fore- ground, $ ah as 3 3 4 1 2 4 | Portraits in | ! Rooms Rie le | Light Interiors) 4 8 16 | 32 1 2 4 8 | Dark Interiors) 1 8 | 16] 32 r fos _ bo a The small figures represent seconds, large figures minutes. The exposures are calculated for sunshine. If the weather is cloudy, increase the exposure by half as much again ; if gloomy, double the exposure. PHOTOGRAPHIC YEAR-BOOKS.— The ‘ Process Year-book” for 1901-2, published by Messrs. Penrose & Co., of London, shows a marked advance upon its predecessors. It is full of beautiful pictures, reproduced by the photography of colour and ordinary plain process-work. Some of these are exquisite in artistic production and accuracy. There are many useful articles. on various subjects connected with photography. The “ International Annual of Anthony’s Photographic Bulletin” for 1902, being vol. xiv., is to hand. It is produced in. New York, the London agents being Messrs. Nliffe & Sons, Limited. It is published at the price of two shillings, and contains many illus- trated articles. Some of the pictures are excep- ticnally beautiful, and most of them are interesting. The book will be found useful to amateurs, as well as to the more advanced photographers. Messrs. Penrose have also sent their illustrated catalogue, which contains much information. The annual number of ‘“* Photography,” published by Iliffe & Sons, is beautifully illustrated by a series of the chief photographs of the year. The Thornton- Pickard Catalogue for 1902 contains several im- portant novelties, one of them being the Focal Plane Automan, which is fully described. It isa distinct advance towards obtaining perfect pictures. LONDON GEOLOGICAL FIELD CLAss.—We under- stand that the annual series of Saturday afternooh excursions of the London Geological Field Class, conducted by Professor H. G. Seeley, F.R.S., com- mences on April 26th, when a visit will be paid to Erith. The excursions will be continued on each succeeding Saturday. except on the Saturdays before W hitsuntide and in Coronation week, until July 12th. These excursions will afford the means of examining some of the greater movements which the rocks of the South-east of England have experienced in foldings which changed ‘their level. The denuding action of the sea in levelling the land will be examined and compared with the action of atmospheric denudation, as seen in the forms of the parallel hill ranges and valleys of Surrey and Kent. The work of the session will illustrate the geological structure of the districts known as the Weald and the London Basin. The strata examined will comprise all members of the Neocomian and Cretaceous groups, the Lower London Tertiaries, and the gravels and brick earth of the Thames Valley. Opportunities will be given for collecting fossils from these strata, and from the Upper Oolites, upon which they rest. Further particulars can be obtained from Mr. R. Herbert Bentley, the honorary general secretary, 43 Glou- cester Road, Brownswood Park, N. Coccus OF THE ORANGE-TREE.— This year I have noticed a greater number than usual of those small dark scales on the rind of oranges which when examined with a pocket lens bear so striking a resemblance in shape and general character to a mussel-shell with its convex side uppermost. I have been much interested in examining these curious relics of creatures whose life-history is so markedly dissimilar to all other known orders of the animal creation, These singular creatures belong to the order Hemiptera, and are closely allied to the aphides. They belong to the Coccidae, the same family as those great pests of the horticulturists, the ‘‘mealy bugs,” the cochineal insect, ‘‘ Coccus cacti,” of so much mercantile value for dyeing pur- poses, being also of the same genus. Carefully removing from the orange with a needle one of these scales, and placing it under the microscope, concave side upwards, we usually find the shell is more than half full of oval pearl-like eggs, probably forty or fifty in number, and one ‘wonders how they got there. Singular to say, while the uni- versal law of Nature appears to be progression towards perfection, here we find the exception, in that the female coccus becomes more and more imperfect as she approaches the com- plete state. Having arrived at maturity she selects the place where she intends to feed, then once for all inserts into the plant leaf, stem, or fruit her proboscis, which cannot afterwards be again withdrawn, and there she remains, de- stined for the future to be simply an animated stationary suction-pump. Henceforth she gradually SCIENCE.GOSSTP. 35: and imperceptibly loses all trace of articulation in body and limbs, until all former resemblance to, or indeed indication of, an insect has com- pletely vanished, and she appears a total wreck, “sans everything.” Having laid her eggs, which remain under her, she finally shrivels up to a dry husk, and is now nothing but a protecting shield to the enclosed and underlying eges. She will never see her progeny, and they can at most only know their poor mother as a snug shed with a low-arched roof from which they will too gladly emerge upon the first opportunity. The male coccus is a small, short-lived, white-winged fly. Mr. C. J. Gahan says: “Some years ago the orange plantations of California were threatened with ruin owing to the ravages of [cerya purchasi, which had been accidentally imported from Australia, and had spread with great rapidity. Experts were sent to Australia to try and discover the natural enemies of the insect in its native country. It was found that the scale-insect was there kept in check by dipterous and hymeno- pterous parasites, but chiefly by the larvae of a lady-bird beetle. A number of these beetles and parasitic insects were brought to America, and set to prey upon the coccidae. When they had multi- plied sufficiently they were distributed amongst several orange plantations, with the result that many were soon almost entirely cleared of the scaly bug.” In the year 1845 Mr. G. Newport, F.RS., at that time President of the Entomological Society, said in his anniversary address that ‘so complete had been the ravages of the coccus of the orange-tree, that one of the Azores—the island of Fayal—lost its entire produce from this cause alone. The usual annual exportation from Fayal had been 12,000 chests; but in 1843 not a single chest was exported.” This amount of injury to a whole population by a diminutive and apparently contemptible insect was the result of but three years’ ravages. Well might the President say: “The effects of this insect on a single article of luxury might fairly be adduced to show that entomological inquiries are deserving of full attention.’—Samuel Howarth, 26 Grange Crescent, Sheffield. PupAa Huntinc.— Hunting for lepidopterous chrysalides may be carried on all the year round, but the summer and early autumn months wil! be found the best. For equipment an ordinary garden trowel and a box filled with moss are all that is necessary, patience and perseverance ex- cepted. It is quite likely that the bag at first will not be a large one, but the pupa digger who at the first unsuccessful essay throws up the hunt in disgust would probably have found his toil amply rewarded at the second or third attempt. It is hoped, however, that the hints given here may save those who have not tried this mode of collecting, the expenditure of a good deal of the time and trouble which are the result of inexperi- ence. First, heavy clay soils should be avoided, or ground which is so hard as to present a serious obstacle to the trowel. Next, when the ground is sodden with recent rain it should be left, and the pupae looked for upon trees or under loose bark and moss. They are, of course, often found when gardening, whilst turning over sods of turf or digging up roots; but these are chance finds as to which no rules can be laid down. By searching methodically in the manner here indicated, the pupae of some rare moths, otherwise difficult to procure, may with tolerable certainty be obtained to breed the perfect insects. The most productive trees are the oak, elm, birch, poplar, ash, hawthorn, and willow. The trowel should be inserted to the depth of about four inches in the interstices of the roots. The sod thus removed may be put on one side and the cocoons gently sought for with the hand, along the under surface of the tree root, to which they are often found to be adhering. The sod should now be lightly tapped with the trowel, and if there are any pupae in it they will pro- bably fall out. If the sod is of light dry earth, it will easily fall apart afterwards by shaking. when a more minute examination may repay the searcher. It is of little use digging at a greater distance than eight inches from the trunk of a tree, and in the case of trees other than those I have mentioned the pupae are more likely to be found under the loose bark or moss than at the roots. Exception must be made in favour of those of Trachea piniperda and Boarmia abietaria, which are found at the roots of fir and spruce and yew trees. With the approach of winter pupae become more difficult to find. They have many enemies, such as birds, mice, and even earwigs, that feed upon them. ‘The best course then is to commence searching within a few weeks of the transformation from the caterpillar to the pupae stage having taken place. The collector, however, should always be prepared for the possibility of some of his finds drying up. This arises as a rule from their being injured, either before or during their capture, or having been kept too dry. Some are tougher than others, but all require the utmost care in handling. Meadows and parks dotted with trees of large growth make the best hunting grounds. Of the trees, those where the grass beneath has been worn away by cattle or which are situated on the banks of streams are the most likely hunting grounds. A solitary oak or poplar in the middle of a field is an ideal spot for the pupa digger, especially if the soil is dry and friable. Pieces of loose bark still adhering to the tree and every nook and cranny of the tree itself should be carefully examined. In some cases the cocoons will be found concealed between a pair of leaves joined together. The chrysalis of Platypteryx falcula chooses the leaves of the birch for this purpose. It is found in June and again in September. Another species of the same genus. selects the leaves of the beech. The moss growing at the base of trees should also be carefully re- moved and examined. Woods, as a rule, will be found unproductive. This does not apply, how- ever, to their extreme edges, nor to the borders of the clearings often to be met with even in the heart of a forest. Clearings in elevated positions and with a northern aspect are the best. When a hard sod has been removed from the base of a tree without result it should, whenever possible, be replaced in the cavity from which it was taken. The earth having been loosened forms a sort of trap, and one may have an excellent find on the next visit. Pupae digging can be recommended as a healthy and interesting pursuit, and rare specimens may be obtained in this way at a season of the year when the hope of capturing fully developed insects of the same species is quite out of the question. Until, however, accustomed to the accompanying physical inconvenience, one must expect some tiring days.—A. ZL. Clifford, 37 Saint Augustine Road, Camden Square, London, N.W. 352 Messrs. BLACKIE & SON contemplate a re-issue of ‘*Kerner’s Natural History of Plants,’ a work which in its English form is identified with the name of Professor F. W. Oliver, of University College, London. Professor Oliver’s translation, in the production of which he had the assistance of Lady Busk, B.Sc., and Mrs. M. F. Macdonald, B.Sc., was first published some seven or eight years ago. The new edition, which will be issued at a considerably reduced price, will be sub- stantially a reprint of the original English edition, with a few necessary alterations and corrections. NOTICES OF SOCIETIES. Ordinary meetings are marked +, excursions * ; names of persons following excursions are of Conductors. Lantern Illustra- tions §. BIRKBECK NATURAL HISTORY SOCIETY. April 12,—* Bickiey, for Chislehurst, St. Paul’s, 2.7 P.M. E. Bowers. Miss GEOLOGISTS’ ASSOCIATION, LONDON. April 4.—§ “ Klondike, its Geology and Mining.” A. Miers, M.A., F.B.S. s, 12.—* Zoological Gardens. P. L. Sclater and F. E. Beddard. 5» 26.—*S.E.R. Main Line widening (new cutting for Elmstead Station). T. V. Holmes, F.G.S., and C. W. Osman, A.M.I.C.E. ENTOMOLOGICAL Professor H. SourH LONDON SocIEry. April 10.—}+ “Some Species of British Lepidoptera and their Geographical Distribution.” R. South, F.E.S. > 24.—7 “The Lesser British Lepidoptera.” Alfred Sich, F.E.S. ‘HAMPSTEAD SCIENTIFIC SOCIETY. April 4.—; General Meeting. “The Nature of Methods.”’ Dr. Wm. Boulting. » 9.—§ Photographic Section. “Flower Photography.” >, 11.—yf Natural History Section. ‘Notes on the Flora of Hunstanton and District.” OC. S. Nicholson. 5 ll.—y ‘On the Approximation of the Forms of Living Mollusca to their Fossil Prototypes.” Hugh Findon. » 25.—y Photographic Section. Printing.” AND NATURAL HISTORY Scientific “Demonstration of Silver NortH LoNDON NATURAL HIsTORY SOCIETY. April 5.—* Visit to Zoological Society’s Gardens, Regent’s Park. » 8.—¥§ “Some Extinct Bird Reptiles.” Miss H. K. Brown. » , 8.—f “ Notes on some Seaside Plants.” C.S. Nicholson, F.L.S. », 22.—§ “ British Freshwater Fish.” G. Hamby. ‘SSELBORNE SOCIETY. April 4.—Museum Evening and Annual Meeting. ROYAL INSTITUTION OF GREAT BRITAIN, April 7.—General Monthly Meeting. NOTICES TO CORRESPONDENTS. To CORRESPONDENTS AND EXCHANGERS.—SCIENCE-GOSSIP is ‘published on the 25th of each month. All notes or short com- munications should reach us not later than the 18th of the month for insertion in the following number. No communications can ‘be inserted or noticed without full name and address of writer. Notices of changes of address admitted free. EDITORIAL COMMUNICATIONS, articles, books for review, instru- ments for notice, specimens for identification, etc., to be addressed ‘to JOHN T, OARRINGTON, 110 Strand, London, W.O. BusINEsSS COMMUNICATIONS.—AIl business communications relating to ScIENCE-GossIP must be addressed to the Manager, “SCIENCE-GOsSIP, 110 Strand, London. SUBSCRIPTIONS.—The volumes of SCIENCE-GossiP. begin with ‘the June numbers, but Subscriptions may commence with any number, at the rate of 6s. 6d. for twelve months (including postage), and should be remitted to the Manager, ScIENCE- “Gossip, 110 Strand, London, W.O. TuE Editor will be pleased to answer questions and name specimens through the Oorrespondence column of the magazine. Specimens, in good condition, of not more than three species to ‘be sent at one time, carriage paid. Duplicates only to be sent, which will not be returned. The specimens must have identify- ing numbers attached, together with locality, date, and par- sticulars of capture. SCIENCE-GOSSTIP. Novrice.—Contributors are requested to strictly observe the following rules. All contributions must be clearly written on one side of the paper only. Words intended to be printed in italics should be marked under with a single line. Generic names must be given in full, excepting where used immediately before. Capitals may only be used for generic, and not specific names. Scientific names and names of places to be written in round hand. THE Editor is not responsible for unused MSS., neither can he undertake to return them unless accompanied with stamps for return postage. NOTICE. SUBSCRIPTIONS (6s. 6d. per annum) may be paid at any time. The postage of SCIENCE-GOSSIP is really one penny, but only half that rate is charged to subscribers. EXCHANGES. NovicE.—Exchanges extending to thirty words (including name and address) admitted free; but additional words must be prepaid at the rate of threepence for every seven words or less. WANTED.—Microscopy books and “etceteras.” Exchange Indian Bird Skins, and complete collection Maltese Land Shells.—Major Bechen, Wadebridge, Cornwall. TuBES, Marine Dredging, rare Zoophytes, Worms, and Pleuro- sigma angulatum sent in exchange for Scientific Work-, English or foreign, or other offers.—(Rev.) Eustace Tozer, 17 Alma Road, Sheerness. W ANTED.—Store-boxes for Lepidoptera ; also “ The Entomolo- gist’s Weekly Intelligencer.” Will exchange “* The Naturalist’s World,” 4 vols. complete, and ScIENCE-GOssIP 1865 to 1868.— E. Petrie, 56 Brunswick Street, Chorlton Medlock, Manchester.’ OFFERED.— Volumes “ Paleeontographical Society,” illustrating British fossils ; set of each of “Midland Naturalist,” “ Journal Applied Microscopy,” ‘“‘ American Microscopical Journal,” * The Scientific Enquirer,” “* Knowledge,” ‘** Insect Life,” also numerous works on Microscopy s;1d Natural History. Wanted in ex- change good Geological Lantern Slides of River, Mountain and Coast scenery.—Captain Cooke, Westbury, Bristol. CaRL Voat'’s “Mammalia,” 2 vols., 13 by 10, 40 Plates, 270 Illustrations, unsoiled. What offers ?--C. Heel, Stechford, Birmingham. W.NTED.—British marine shells, eggs of peregrine, sparrow hawk, reed and wood warblers, woodpeckers, cuckoo, etc. Offered, many choice foreign shells and other natural history specimens. Good Colonial and British stamps. State wants.— Chas. Jefferys, The Chipping, Tetbury. WANTED.—Loan of mounted slides of ‘“* Micro-Fungi”; give in exchange for their use, negatives, or prints of same; great care will be taken of slides, which wiil be returned safely.— John Chuter, Lion Green, Haslemere, Surrey. ' DIATOMS.—Exchanges in Diatoms requested, either in slides or material. Wanted Volvox, either living or mounted.— Richard Borrows, 49 Victoria Embankment, Darlington. ENTOMOLOGY.—Will collect in any Order; in exchange for Coleoptera, Hemiptera, or Lepidoptera of Europe, Asia, or Africa.—Oharles Stevenson, 906 St. Urbain Street, Montreal, Que., Canada. CONTENTS. PAGE GEOLOGICAL NOTES IN THE ORANGE RIVER CoLony, By Major B. M. SKINNER, R.A.M.C. Illustrated .. oe OlL THE PLUM AND ITS ALLIES. By SOPHIA ARMITT bo Terr Our CocKROACHES. By E. J. BURGESS Sopp, F.R.Met.Soc., 18) OF Ses 50 30 6 a ae ae -. 324 RUBBLE DRIFT AND DRY CHALK VALLEYS. By EDWARD A, MARTIN, F.G.S.° .. oe a a0. 5 si 1326 AN INTRODUCTION TO BRITISH SPIDERS. By FRANK Percy SmirH. Illustrated oye 90 sie So 8) SPONTANEOUS COMBUSTION IN Man. By J. L. F. MITCHELL, M.A. 00 ce 06 00 oe e. oad Books To READ. Illustrated .. se 06 00 fo oR SCIENCE GOSSIP .. 6 oD 50 a0 50 Bo Gris) Microscopy. Illustrated bio So ae fe .. 9341 Borany. Illustrated .. ae a ae aa oo ©6343 ASTRONOMY 45 50 50 oe ae ~. 346 OHEMISTRY 30 40 OD a0 50 50 ste, 848) PuHysics 50 50 50 60 30 ete 90 oe) O49 PHOTOGRAPHY .. eye 60 So oc -. 350 NOTES AND QUERIES .. sie 20 : 50 «. 300 NOvICES—EXCHANGES fe we sie 56 ve Ow SCIENCE-GOSSIP. W. LONGLEY, ENTOMOLOGICAL CABINET’ AND APPARATUS MAKER. NATURAL HISTORY AGENT AND BOOKSELLER. SOUTH BENFLEET, R.S.O., fe SS ai oc Nets, Breeding Cages, and Apparatus of every descrip- tion; Cabinets for Insects, Birds’ Eggs, Minerals, Shells, Coins, etc. etc. ; Pocket Boxes, Store Boxes, and Book Boxes. Sheets of Cork any size to order. EDUCATIONAL COLLECTIONS IN ALL BRANCHES OF ENTOMOLOGICAL STUDY CAREFULLY PREPARED FOR SCHOOLS, INSTITUTES, &c., AT MODE- RATE CHARGES. Single complete cases, illustrating ““ Mimicry,” &c., from 3s. each. Entomologists’ apparatus of all “kinds kept in stack. A large col- lection of Exotic Butterflies and other Insects. Lists Free. Correspondence invited. ALFRED H. BASTIN, 28 New Road, READING. BUTTERFLIES. MOTHS. Best value given for Sollections from all parts of the world? Travellers’ own Collections named, ranged, and mounted. Many fine species for sale. PERCY |. LATHY, - Sydney Road, Enfield, England. ar- A FICMULESS CINEMA TOGRAPH For taking and projecting life-size animated photographs with greatest perfection to the extent of over 550 pictures. Specially constructed for the Amateur or Professional. Price £9 9s, Negatives and EES UNG : Plates 9/6 each Subject Plates, 36. 6d. allowed for each Plate ! returned unbroken. SIMPLE and RELIABLE MECHANISM. Kammatograph and Lantern ready for projecting. WEIGHT about 8 Ibs. MEASUREMENTS, 14 in. X 13 in. X 3% in. With the KAMMATOGRAPH an ordinary dry glass plate is used instead of cinematograph film. The method of developing KAM- MATOGRAPH plates is exactly the same as with dry plates, thus bringing cinematography within the reach of all. SPECIALITIES—Can be seen at the Manufacturers’. High-Class Lanterns and Jets, Hand-Fed Arc Lamps, and Patent Rheostats (roo to 200 volts). PRICES ON APPLICATION. Write for Catalogue to the Manufacturers :— L. KAMM & CO., Scientific Engineers, Works—27f POWELL ST., GOSWELL RD., LONDON, E.C. Photogra phy | in Natural Natural Colour Photographs made to order from Natural History Specimens, Microscopie Objects, Works of Art, &c., either as lantern Slides or larger transparencies. APPARATUS AND MATERIALS FOR ORTHOCHROMATIC PHOTOGRAPHY AND PHOTO-MICROGRAPHY. SANGER SHEPHERD PROCESS. A simple, inexpensive, and reliable process, based upon sound scientific principles, for obtaining photographs of any object in its natural colours, faithfully reproducing every shade and tint Ali Apparatus and Materials for work= ing the process now ready. COMPLETE OUTFITS for STANDARD SIZE LAN- £2 CS TERN SLIDES from : THREE COLOUR FILTERS from 15’- per Set. New Descriptive Booklets and Catalogues now ready. {GF See ‘‘ Photography in 1gor,” “* SctENcE-GossIP,” January 1902, page 232. SANGER SHEPHERD & CO., Factory and Offices : Telegrams: ‘‘ AUKS,” LONDON. > EST/ BLISHED 1760. Sk ZENS. (HENRY STEVENS. 5, 6, & 7 Gray's INN PassaGe, Rep Lion StrreT, HoLtroxn, Lonpon, W.C. Telephone : 1824 GERRARD. D. PELL-SMITH.) AUCTIONEER AND YWALUER, 38 KING STREET, COVENT GARDEN, LONDON, W.C. "Every Friday at 12.30 Sales are held at the Rooms of Microscopes and all Accessories by best makers. Micro- scopic Slides, Telescopes, Theodolites, Levels, Electrical and Scientific Apparatus, Gameras and all _ kinds of photographic Apparatus. Lanterns by leading makers. NATURAL HISTORY SALES once and twice a month. CURIOSITIES, WAR RELICS, POSTAGE STAMPS, once a month. Lantern Slides in great variety. Catalogues and all particulars of Sales, post free. the ee a, 5 igh Murer SCIENCE-GOSSIP. Every Adjustment for Critical Work. Be dis C AssevA TOG Us ii _ PBEGK'S “IMPERIAL” MICROSCOPES. ON APPT Pparion- R. & J. BECK, Ltd., 68 Cornhill, E.C. Twe minutes’ walk from the Bank Station, Central Electric Railway. WATSON’S LATEST MICROSCOPES, APPARATUS, &c. WATSON’S SPINDLE -TWO-SPEED NEW MIGROSCOPE. WATSON’S “HOLOS FRAM.” oncer- folly Effective. A New Instrument on the) well-known “Fram” Modei, | But fitted with compound substage, -with| screws to centre and rackwork to focus, | and mechanical stage of besc quality. It ‘is the cheapest completely fitted Micro- scope that is made, and, like all of Watson’s Instruments, is of finest work- manship. Stand only, with one Eyepiece, £8. The two speeds are obtained in a single screw by the use of a milled head having its centre extended in the form of a spindle one-sixth of its size. The spindle is rotated for a quick, and the milled for a slow movement. Can be fitted to almost any Microscope at small cost—approximately 5/-. For full particulars see Watson's Supple- mental List of Microscopes. WATSON’S HOLOSCOPIC OBJECTIVES WATSON’S HOLOSCOPIC EYEPIECES WATSON’S HOLOSCOPIC OIL-IMMERSION CONDENSER best low-power Condenser obtainable. WATSON’S UNIVERSAL CONDENSER f Every Amateur should have one. Full particulars of the above, also of Watson & Sons’ Unique Microscopes, Objectives, and Appa- vatus are contained in Lilustrated Catalogue No. 2, post free on application to W. WATSON & SONS, Opticians to H.M. Govt. ESTABLISHED 1837.] for full particulars see Watson's Supp emental ' List of Microscopes. ) should be used by all up-to-date Microscopists. They are the finest for practi..al work. FINE ADJUSTMENT 313 High Holborn, LONDON, Branches—(6 FORREST RD., EDINBURCH |; 78 SWANSTON ST., MELBOURNE, AUSTRALIA. — SrortiswoopE & Co. Lrp., Printers, NEW-STRFET SQUARE, LoNDON. INTERESTING MICRO. OBJECTS. Foraminifera— group of about 12 species - Opaque ae Foraminifera from N. Atlan- tic, S. Atlantic, Adriatic Sea, and many other locali- ties, each .. Sean Malarial Parasite in ag laries of Brain as /= Flower Seeds, i in M BFOUPs very pretty.. /- . Kavolinets in foe “tissue Lily -- 3/= Grong of Saeed Spicules from St. Peter, Hungary.. Butterflies’ Eggs, arranged in group, opaque, each 5/6 & 10/6 WATSON’S Object Catalogue ; (No. 3) Is the most comprehensive . in the world. Post free. — Every Microscopist should subscribe to WATSON’S Circulating Slides. 240 SPECIMENS ~ On loan for £1 1s. : q w.c.