•^< m mt mMMiM^Mi: !^/^>!^7. ^ ^i^m- ^m ^ T-, . ONT. V ILLUSTRATED ^^ SCIENTIFIC NEWS Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A. /->\\ " Let Knowledge grow from more to more." ^U — Tennyson. ■ k / Volume 111. (new series.) JANUARY TO DECEMBER, 1906. M c-i) ^-K. M london: KNOWLEDGE OEEICE, 27, CHANCERY L.\Ni:. W.C. [All Rights Reserved.] London : King, Sell & OLnixr,, I,Tn., 27, Chancery Lank, W.C. I ^.^^ KNOWLEDGE & SCIENTIFIC NEWS. INDEX. \ljL-lli, Dr. (liorgio, on 'I'lie Asteroid T.G. .Xeronautics : , Aerial Navig-ation. Major Baden-l'owell .. Flying Machine, a Successful Air. Liquid, The Knudsen System Alcohol as a Stimulus to Life ... .\niinals. Rare, Living in London, P. L. Sclater Arizona, The Petrified l'"orest of .Vrtificial Respiration .\rtificial Rubies ... Atmosphere, Electric Production ol Nitrates from the. Professor Siixanus Thompson, on Australian Meteorology .. Astronomy : Asteroid, An Interesting New .\steroid, An Interesting; New, Professor E. Tarrida del Marmol .\steroid. The New 1906 T tronomical Photographs, .\. Smith, ^^95, .Vslronomical Notes, C. P. Butler, ,yo, 3v 405, 4;,!, 457, 478, 507, 540. 566, 5? .\urora of No\ . 15, the, W. Shackleton ... Belgian Royal Ohservatoiy Double Stars Stellar Distances, T. K. Heath Hatli'M Powell, .Major, on The Latest Develo])- mi'iil in .\erial Na\igation ... Badgley, W'., on The Mag;netism of the Sun ... Barr-Brown, .\n .\ncient Mazer: .\n Old Wassail Bowl Bastin, S. L., on the Evolution of the Flower Beetle, .\ Long Lost {Loniccliusa s/rnmosa) Belgium, Kov.il Observatory of Bcnham, C. F., on .V .Simple I I;irmonogr.i|5h ... ,, ,, ,, Miniature ., ,, ,, ,. .Simple (iaslighter ,, The Celluloid hllectric Machine liioscop*-, or Long I'Ocus Microscope. The I'jnile ( luarini Birds. Origin of, W. P. Pvcraft Prot<'.-tion of and Mamm.ils. Coloialron of, [. Lewis PACE 500 602 .5-'8 539 580 379 475 587 437 477 34S 419. 443 386, 612 374 534 .537 556 662 411 i2 r 584 534 3-5 45- 401 .565 55- 410 :. 40.- PAGE Bleaching, Electrical ... ... ... ... 563 Bomb.-iy, The Flora of the Presidencv of ... 577 Bonhotc, J. Lewis, on the Coloration of .Mam- mals and Birds ... .. 316, 343, 372. 402 Hook Club, The " Know led(;k "' ... ... 6jo H 507. 540. 566, 388. 612 Can.als on M;n's . . Carbon: .\ New Oxide of, fP ]. II. {•"enton ... Card Calculator, Tavlor's Cattle. The .So-called Copper Teeth of ... Cell in the Higher Plants, the Studv of the. H. .\. Haig 513. Celluloid L^iectric Machine. The, C. 1*". Benhani Chemistry of Proleids, The. Ida .Smedley Chemical Notes. C.-.Ainsworth Mitchell, 339, 387, 4i2, 439, 480, 508, 542. 368, 389, Cloud Photography, W. J. S. Lockyer ... Co.ist Denudation in England, E. .\. Martin, 348, Cohesion, Studies in. Dr. .Alfred Gradenwitz ... Correspondence, 320, 337, 373, 382, 511. ^{^2, 546, 586, riiition bv Coron.i and Magnetism, The, Dr. Trowbridge's lixperiments C<;smogony, The New, J. Iv Gore Crommelin, .\. C. D., on The New Planet. TG. 369 412 463 586 5-'6 565 427 407. 614 495 563. 613 404 397 523 535 Dalmas. II. de St., on \\"h:il is at the Centre of the Ivnth 738 Denudation, Coast, in l^ngland, F. A. Martin. 348, 370 Dinosams, New ... ... . . . .. 411 Disintegration of .Saturn's Ring .System, \\". J. Knight ... ... ... . . ... 320 Double .Stars, .\ Catalogue of ... ... ... 337 Durnford, Lt.-Col,. on The Flight of Flying L'lshes ... ... ... . . . . 603 Dull. W. ,\., on I-^olithic M:ni ... .. ... 399 D\ \ iria Terns, London's Transformation 337! 365 KNOVVLKDCrl-: & SCIENTIFIC NEWS. Kartli, What is at the Ccntrv of thi H. dc St. Dahlias „ 'IIk- Interior of the ,, ,, .. ., ,. i\al. Hert'sfdrd iiii^rani To Cloud, Lai^litiiiiit; I'lasiies Ironi, W. J. S. Lockycr ' l-larlh's Crust, Thickni-ss ol the, h'rank Harris l\aith<|uakis, 'I'he San i''raiK'isco Caniille i''laiiimari()ii, on lvartii(|uake Areas Hols and Klectric Litjht ... Electric Bleaching ,, 1-ight and Eels ... Machine, The Celluloid, C. 1{. Iienham ,, Nitrates and Fertilisers ,, Production of Nitrates from the .\tnio- sphcrc. Prof. Sihanus P. Thomp- son l-!lection. Our Own (ieneral 1-Tement, New Radioactive, .\ .. Eigg, The .Scuirr of Ivlio't, Sir John, on W'nvM Weatlier Eolilhic CcntroAvrsN , The, j. Russell i.arkhy on Man, W. .\. Dult" on ' ... h;puortii Church, .\ncient .Mazer in ... Ec|uatorial. for Small Telescopes, 1-". W. Pollard l'".ruption of \'esuvius. The Exohilion of the h'lower. The, .S. I.eonai'd n.islin .; PAGE 34 7 599 412 -199 536 470 47° 56s 377 347 37t 332 577 38J 399 585 ^ 344 l'"eiilon, 11. J. H.. 011 Oualilatixe .\nal\sis 380, 412 l-'ish, I- light of Flying, Lt.-Col. Durnlord ... 603 i-lora of the Presidency of Bombay ... ... 577 I'lower, The E\olution of the, S. L. Bastin 321, 343 ■•"lying .Machine, -A Succe.ssful ... ... ... 328 i'lammarion, Camille, on Earthquakes ... 582 I'"otherbv, H. .\., on Light and the \'isual .Sense 605 (ias-Lighter, A Simple, C. V.. Benham (icneration f)f Life, The .Vrtificial, Ceh. Rath. Prof. Dr. \V. Roux (Icological Notes, E. .\. Martin. 35Q, 388. 408, 459, 481, 508, 543, q68, sgo, Ciiant's Causeway, Some Note.s on the, E. .V. Martin ... ... ... lilaciation in Snowdonia Core, j. 1-^., on Holes in the Hea\en.s ,, ,, on The New Cosmogony (Ml The ,Stellar L'nixcrse ... (irace Cup, The Glastonbury (iradenwitz. Dr. .\lfred, on -Studies in Cohesion (ira\itation Re.search, Pendulums u.sed in, W. H. Sharp (iuarini Lanile, on the Bioscope, or Long I'ocus Microscope (ivp.sv Moth in .\nierica. The ... 401 484 432. 6'5 607 332 467 523 449 352 559 446 H Haig, Harold .\., on liritabilitv ... The Study of the Cell the Higher Plants 1 iarnionograph, .\ .Simple, C. E. Benham ,, Miniature, C. V.. Benham Harris, L'rank, on the I'hickness of the I^.irtl Crust Heath, •]■. E., Stellar Divlances Heavens, Holes in the, j. !•;. Core Heredity, The Study ol , Horn of Ulphus, The Renowned Howes, The Late Professor Hybridization of Plants, Inlernational C( ference on Hydrogen -Sulphide, Oualitati\e .\nalvsis W'i out the Use of, 11. 1. H. Fenton ... 529. PACE 246 . 526 325 452 412 5-56 467 553 533 3 -S3 555 380 Infinity of the Focus, The Rule for, Dr. (1. H. Bryan ... ... ... ... ... 332 Ingram, Beresford, on the Interior of the l^arth 327 liritabilitv. Reaction of Protoplasm to -Stimuli 426 Jones. ChaiJiiian, on Photogra|)liy , " Pure and \pplied (See Photography) K Knight, W. J., on the Disintegration of -Saturn's Ring -System ... ... ... 320 ■■ K.NOWLEDc.i; " Book Club ... ... ... 610 Konig Flames, .\ No\el Use of ... ... 575 Larkby, J. Russell, on the l-'olithic Controversy 382 Leek, Sewage from the ... ... ... ... 3i8 Life, Alcohol a.s a Stimulus to ... ... ... 580 ,, The .Artificial Generation of ... ... 484 Light and the X'isual .Sense, H. A. Fotherby ... 605 Lightning Mashes from Earth to Cloud, W. J. S. Lockyer ... ... ... ,.. ... 599 Liquid .Air, the Knud.sen System ... ... 539 Lockyer, W. J. .S.. on Lightning Flashes from Earth to Cloud ... ... 599 Lockyer, W. J. .S.. on Cloud Photography 495 London, Rare Living .\nim;Js in, P. L. Sclater 339 London's Transformation, -Supplement 339, 365 Lvdekker, R., on Some Rudimentary Structures 472 M .Magnetism and the Corona, Dr. Trowbridge's l''xpp('lin Airship ... PAGE 475 379 397-8 .585 .369 455 552-3 549 520 322 525 520 493 4*'9 468 321 347 445 369 .. 496-7-8 447 .^63 6-7, 526-7 ... 363 474 349 .585 590 360 436-7 2- 55° 324 586 435 363 476 322 3.58 512 471 345 424 424 591 590 602 STAR MAPS. No. 7 Virjfo, Corvus Centaurus No. 5 Arjfo, Canis Major No. 8 Corona, Bootes, Corna Opp. page -il34 J 380 ,, 610 315 KDOQiledge & SeieDtllie fleois A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. 14. [new series.] JANUARY, 1906. [staloner"? Hall J SIXPENCE NET. CONTENTS see page VII. Is Public Interest in Science on the Decline in England ? WE sincere!}- trust not. The British Science Guild has lately been incorporated, under the Presidenc)- of the new Minister for War, with the special object of guarding against such a contingency, and has all the appearance of having come to stay. And yet there is some evidence to the effect that periodicals devoted to scientific subjects are not read to the extent that we would like to see. During the past year no less than three such journals have died of inanition. One, a magnificently got- up and very well edited magazine of technics, another, a most useful organ of metallurgy, and the third an interesting record of nature. Yet these have each failed to attract sufficient readers to justify their existence. It is a monstrous pity ! What i'j the cause ? It is generally contended that scientific interest is growing apace, and that the general public is daily becoming more imbued with a craving for knowledge. If so, why these failures in the scientific press ? As regards our own position, although not very long ago we also were deploring the scanty support we were receiving, times have changed, and, possibly in consequence of the disappearance of the other journals, the outlook is now far brighter than it was, and our position seems assured. Still, considering the circumstances, it might have been expected that a larger proportion of the reading public would have gone in for a journal devoted to science, while of not too technical a character. The modern public is, howe\cr, veiy critical, and e\cn In per-critical. " None but the best "' is now the cr}-. Such a sentiment is praiseworthy, but it can be overdone. and if the acme of perfection is noi to be obtained it is surely better to take the less good and encourage it to improve. Haifa loaf is better than no bread, and the sale of many half loaves enables the baker to give more for the money. A really good organ of popular science is a most desirable institution. We know, only too well, our shortcomings, but without more encouragement and a larger circulation it is not possible to produce a periodical such as we should like to see. We would, then, make a strong and earnest appeal to all who have scientific progress at heart, to co- operate in improving this journal by doing what they can to increase our circulation. If only each one of oui' readers would take two copies instead of one (and the spare copy makes an acceptable present to many a poorer worker in science), with our circula- tion doubled, we would gladl}' undertake to double the size of the paper, and pa\' more for suitable articles and choice illustrations. It would be of the greatest assistance to the immediate improvement of the journal if all those who propose to take it in regularly would subscribe on the new five-years' system. This has been specially arranged to be of the greatest benefit to the reader, saving him much expense and trouble. \\'e occasionally have opinions from individual readers, but these are often contradictor}- and bewildering in their suggestions. We are anxious to ascertain the wishes of the majority, and with such object we enclose in this number a post card in the hope that all readers will kindly enter thereon their opinions and post it to us. 3i6 KNOWLEDGE & SCIENTIFIC NEWS. [January, igc6. The Colora.tion of MaLmmoLls OLiid Birds. By J. Lew] Uonhote, M.A., K.L.S., F.Z.S., .M.B.O.U., etc. I Continued from page 294.) Ixt us now stufly for a short time the migrant birds that breed in Pohir regions. These may be divided into two chisses : — (i.) Those from tlie temperate regions, which gradually breed as far north as is consistent with their wants. (2.) Tho.se that winter in the tropics and breed in the extreme north, but not in the inter- vening region. We need not notice the first class here, as they belong properly to the north temperate region, from whicli they are stragglers. The second class consists, for the most part, of bright-coloured birds that assume their bright livery in the tropics, and that wear in winter a duller dress, assumed in northern regions*. The Lapland bunting (Calcanm lappouicus) is a good example, for the cock ha.s n bright black and red breeding plumage, much brighter than that of its near ally, the snow bunting (Ph'clroplicnax nivalis), which has a much more north- erly \\ inter habitat. .Another good instance of a bright-coloured northern breeding bird is the red-breasted swallow [Hirundo erythogaster), which passes the summer in North-East Siberia, and the winter in Burma, and countries to the south. This bird does not, as far as I am aware, moult in these northern regions, and, consequently, as we should expect, retains its bright red colour, which was ;issumed in the tropics (where the tempera- ture and food are conducive to high vigour) throughout the year. It would be impossible to enumerate all the birds which may be considered in this class ; the Limicolse offer many examples, and the knot (Tringa caiiuius) may be taken as very typical. This bird assumes in early spring, when in the tropics, a very deep chestnut plumage. It then migrates to the extreme north to breed. After breed- ing it moults and becomes a dull greyish white bird, so that both its plumages are in keeping with the colour characteristic of the regions in which they are assumed. \ow it has long been a puzzle to me whyf the young knot, bred and reared in the north, should yet be able to assume a browner and pinker plumage than its parents, although in Arctic regions. The explanation may, however, possibly be due to the fact that when the old birds moult they have had a long journey im- mediately followed by the strain of the breeding season, compressed into the short .Arctic summer, so that we would expect their vigour in autumn to be very low; whereas, on the other hand, the young bird has only had to grow, which is probably n" far less strain * It has been pointed out to me that some birds migrate in autumn before tliev moul'. which is sometimes undoubtediv the case, although I believe that in the majority of instances this is due to their being driven south by early storms before the moult has been completed. In any case the moult would follow so soon after migration that their svslem would not have had time to respond to the more generous influences of a southern clime. t For further suggestion on this point see P.Z.S. 1901, p. 325. on its system than that undergone by the parents. The result is that the young are enabled, although in Arctic regions,* to assume, to a slight extent, a colour belong- ing rather to the tropics. This case is, to my mind, of considerable importance as showing that " colour " is dependent far more on " vigour " than on the particular latitude in which it is produced. Knots, when kept in captivity, rarely, if e\er, assume the full deep chestnut which they do when wild, the amount of change depending largely upon the individual. For two winters I endeavoured, by keep- ing these birds at a fairly high temperature, to induce them to assume their full red colour, but it produced no appreciable effect, showing, therefore, that heat has, in this species at all events, but little power. The golden plover at first sight offers rather a puzzle, for in this species the birds, which nest in the southern limit of its range, are duller and in less perfect plumage than those to the north, which is apparently exactly the reverse of what ought to take place. It ihas, how- ever, been proved for some species of birds, e.g., Geothlypis, that those individuals of a species that breed the furthest north, winter furthest south, and, consequently, the full plumaged golden plovers that breed in the far north may presumably have wintered in the tropics, while those that breed with us have never entered the torrid zone. Further evidence in support of this suggestion is given by that nearly-allied species, the grey plover, whose breeding range is entirely in the north, and that only occurs in the temperature zone on migration, for in this species all individuals assume their full summer dress. To take a further example. The ducks may be roughly divided into two groups : — (i.) Those in which the male assumes a dull plumage after the breeding season. (Re- stricted entirely to those species in which the sexes are markedly distinct.) (2.) Those in which the male and female are simi- larly coloured. (Chiefly found in the tropics.) Of this latter group, the long-tailed duck (Harelda glacialis] is the only species which occurs in Arctic regions. This bird, moreover, differs in its plumage from all other members of the .Vnatidae by the fact that there is a summer and w-inter plumage common to both sexes. -According to our present theory, this is quite easy of explanation. The light-coloured winter plumage is assumed in Arctic regions after the breeding season ; the winter is spent in temperate regions, and the sum- mer plumage produced there (imder conditions which must be very mild to an .Arctic species) is brown. II. — The Tropical Regions. Leaving the Polar regions, where the contrasts of the seasons are greatest, let us now turn to the tropics, where the contrasts are least. In the first place, the conditions are such that life can be carried on in a high state of " vigour " during all seasons of the year, and abundance of food in the shape of fruit and insects may be had in every month, the only seasonal differences being those of wet and dry. .Although these naturally have a considerable effect in * Of course the tendency of the species to assume red must be taken into account, as it causes the bird to be pink instead of brown on the breast, though the brown colour appears on the back. As I previously pointed out (loc. fit. ante), the red plumage is in this case probably the older plumage. January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS 317 determining the breeding seasons of many species of mammals and birds, yet the periods of drought and ivet are so local, and determined to such an extent by the geographical conditions of the country, that they need not be considered in a paper dealing with the subject so broadly as the present one. We are, therefore, not likely to find in the tropics great differences of colour, since any climatic change that may exist will tend not to coincide with the breed- ing season, and the latter will be spread over the greater part of the year. From these reasons, therefore, it will be evident that the life of an animal will run much more evenly so far as its metabolism is concerned, and, food and tempera- ture being favourable to a high state of vigour, we should expect to find animals deeply coloured and re- maining so throughout the year. So'Uie animals, however, will be so weak that thev can only exist where the conditions of life are most favourable, so that, although living in the tropics, their vigour will be low. Such animals, therefore, according to my argument, should be white or pale coloured, and restricted to the tropics, while the brighter-coloured tropical animals should be found to have a much w'ider range, the majority decreasing in colour as they spread north or south. Of these brighter animals the tiger and leopard afford good examples. The buffalo of India is black, but in Assam a light variety is found, and the more northern species of Bos are found to be lighter in colour. The squirrels, another brightly-coloured group, are, like the oxen, cosmopolitan, shading through brown to grey in the northern regions. White or grey tropical mammals are \erv scarce, but we may notice the bamboo rat (R/iizomys snmalrensis), which is dirty white in colour and does not range north of Burmah. R. pruinosus, a rather darker species, ranges as far north as Assam, while R. badius and R. sinensis, both dark brown species, range from the south as far north as Bhutan, Nepal, and even Thibet. .'\s regards the liirds, w x- may notice the kingfishers and rollers, typical tropical families, which range to more northern climates. The parrots, which by the same process of reasoning one would expect to find in more temperate zones, only extend to a limited extent. This is probably due to two causes : — (i.) Their sedentar\- habits. (2.) The fact that many of them are not as brighth' pigmented as they appear on the surface, the predominating pigment being yellow. On the other hand, many of them are perfectly hardv, and sl:md our climate out of doors well, so that probablv their sedentary habits have been no small factor in re- strictmg their range. Humming birds also range far toi the north, but have to- retreat before the winter, pro- bably from lack of food, while the sunbirds of India are probably restricted l)y the Himalayas. The riiasi:niichr. are another example of hrigiit-coloured tropical groups extending northwards. Dull-coloured tropical birds (not counting those from temperate regions that have migrated to the tropics) are not numerous. The hoatzin (O pislhocoiiiiis) is, howexer, a good ex- ample of a dull-coloured tropical bird, which, as we might expect, wc find restricted to the tropics, while the bell birds (Chiasniorhynclins) form another good example. {CnntillUi'll.) Ths Venom of Spiders. By C. Ai.NswoRTH 'Mitchell, B.A. (Oxo.v.), F.I.C. {Cuntinued from page 299.) The modern conception of toxines is based on lihrlich's "side-chain" theory, according to which a to'xine is a very unstable body, whose molecule may be represented as containing different unsaturated groups. One of these is termed the liapioplicrc group, and it is that wliich combines with corresponding groups (receptors) in the attacked cells and enables the active or ioxophcre group to> do' its work. If there are no corresponding groups in the blood of the animal the toxine simply circulates inertly and finally disappears. A striking instance of this is seen in the effect of tetanus (lock-jaw) poison upon the alligator, for al- though the reptile itself is proof against the action of tetanus, its blood becomes toxic and will infect a sus- ceptible animal, i.e., one whose blood contains suitable receptors for the toxine. In like manner the hedgehog is refractory to snake venom, and also' tO' spider venom, and its partial in- susceptibility must be attributed to a lack of receptors, for the blood of a hedgehog that has been bitten becomes highly venomous. It is further assumed in Ehrlich's theory that " side chains " are generated within the animal, to replace those of the cells fixed by the toxine, and these, being formed in excess, circulate in a free state in the blood and form the specific immune substance or antitoxine. Now, spider venom answers all the requirements of a toxine, as defined bv Dr. Ehrlich. It is unstable, and produces an antitoxine which is capable of neutralis- ing its action when mixed with it in the right propor- tion. It resembles snake venom in possessing more than one active principle. In snake venom there is one toxine which acts upon the nervous system, a second acting Upon the cell walls, and a third, termed a Iicfm.iilvsiiH\ which dissolves the corpuscles of the blood, .Similarly, in spider venom there is one active principle, which acts upon the nervous system and heart, and another, a hremolysine, with a solvent action upon the red blood corpuscles. This hamiolysine has recently been separated from the common garden spider by Dr, Sachs, who terms it aracluinlysine. It has a very energetic action upon washed blood corpuscles. Those of the rabbit, rat, and mouse .are rapidly dissolved, while human blood cor- puscles are less susceptible, and those of the guinea pig, sheep, horse and ox absolutely refractory. The blood corpuscles of young chickens are at first quite refractory, evidently from a lack of rcce ptrrs to combine with the haptofihore group of the toxine, but as the bird growls older its corpuscles become more susceptible, until after about a month they attain the normal sus- ceptibility of the hen, Dr, Sachs also succeeded in pro- ducing an antitoxine, anli-arachnol ysinc, to this toxine by inoculating animals with gradually increasing doses. The serum of the animal thus immunised was very active, and when mixed with freshly extracted venom neutralised both its toxic and its haemolytic action. There is thus no doubt about the existence of pow- erful toxines in the various species of lathrodcctes and in the garden spider, and possibly in Chiracanthium nutrix, a South European species, and the reason why the bite of these is sometimes insignificant is that the 3i8 KNOWLEDGE & SCIENTIFIC NEWS. [January, 1906. quantity of venom injected is then too small to he effective. The bite of the tarantula, Lycosa tarantula, the fierce- lookingf spider which is very common near Taranto (whence its name), was at one time much more dreaded than that of the malmiijnatte, and is particu- larly interesting- from having- been associated with that curious mental state known as tarant'nm, and its re- puted cure by music. This is described by Ferrantro Impcrato, in a Natural Ilistorv published in Naples after his death, in 1599, and the details he gives are amplified by sub- sequent writers in the early part of the 17th century. In the Philosophical Transactions for 1671 (V'ol. VI., p. 3002) we find an enquiry from Marten Lyster " as to the truth that a person bitten by a Tarantula be not ever when on his feet disposed to and actually dancing after the nature of a Tarantula, which never moves but by skippings. And if so, what axe we tO' think and credit concerning' such and such musical tunes said to be most agfreeable and lending to cure of persons bit by a Tarantula? " Robert Boyle also made enquiries from friends in Taranto. and was convinced of the truth of this music cure, which he ascribed tO' sympathetic vibrations in the patient (Essay of the Great Effects of Motion, 1690, p. 74) : — " But the Eminentest Instance of the Efficacy of peculiarly modified Sounds is afforded by what hap- pens to those that are bit by a Tarantula. For though the bitten person will calmly hear divers other Tunes, vet when a peculiarly congruous one comes to be plaid, it will set him a dancing with so' much vigour as the Spectators cannot but wonder at, and the dancing- will sometimes continue many hours if the Musick do so, but not otherwise." Richard Mead, Physician to- the King, published in 1745 a Mechanical Accouni of Poisons, in which one of the sections is devoted to the Tarantula. He describes \ arious symptoms and asserts that " that the patient being- asked what the ail is, makes no replv, or with a querulous voice and melancholy look points to his breast, as if the heart was most affected." He also describes the dancing cure at length : — "While the Tarantati are dancing they lose in a manner the use of all senses, like to so manv drunkards, do manv ridic- ulous and foolish tricks, talk and act ob.scenelv and : udely, take great pleasure in playing with vine leaves, with naked swords, red cloths, and the like ; and on the other hand can't bear the sig-ht of anything black; so that if any bystander happen to appear in that colour, he must immediately withdraw, otherAvise thev relapse into their symptoms with as much violence as ever." M\ kinds of fables were believed. It was asserted that the patient was only affected so long as the taran- lul;i lived, that the spider itself danced to the same tunc that cured the patient, and that each one had its own specific tune. " This curious frenzy of dancing was infectious, and even those who had not had the mental excitement of the Tarantula's bite joined in as madly as the patient. The disease was said to recur every year at the same time and to be cured ag-ain bv the same music." kt the time that Robert Boyle made his enquiries, this epidemic of dancing was at its height, but even then experiments had been made to prove that the bite of the tarantula was not the cau.se of the mania. Dr. Sanguinetti, of Naples (1693), made two' Tarantulas bite him upon the finger and found that the bite had no more effect than the sting- of an ant ; and his experi- ments were repeated by Dr. Serrao, in 1748, who con- cluded that the bite never produced serious results, and that music liad nothing to do with the tarantula. .\ letter from Dr. Domenico Cirillo, Professor of Natural History at Naples, is published in the Trans- actions of the Royal Society for 1770, in which he stated that there was absolutely no> truth in the sur- prising cure of the bite of the tarantula. He as.serted that each year the disorder lost ground, and that he was confident that in a little while it would lose its credit. There are numerous other accounts extant, showing that the bite of the tarantula is not dangerous, either to man or to cattle, and these are fully supported by the fact that Dr. Robert found the extracts from taran- tulas to be quite harmless. ITie only relic that now survives of the old dancing mania is in the name of the dance of Southern Italy, the tarantella, which, accordingf to^ an old authority, was one of the dances of the tarantati. Similar dancing- epidemics have been known in other parts of Europe, notably during the 14th century, in the Rhine and Moselle districts, where men and women, old and young, danced from town to town, dancingf in the streets, in the squares, and in the churches — every- where. .-^s regards the Italian epidemics, there were probably cases in which the effects of the bite of a malmignatte were attributed to the tarantula, but in most instances fear was probably the main cause of the illness, and produced a state of hysteria, which found its expression in violent and uncontrolled dancing. Scientific Sewa^ge Treactment. TKe Leek Sewage Farm. In Slater's book on " Sewage Treatment," published in the year 1888, there is the following passage : — " Unfortunately there is no subject, outside the range of party politics, on which so much envy, hatred, malice, and all uncharitableness prevail as on the treat- ment of sewagf'." The history of the many abortive attempts which have been made to deal in a satisfactory manner with sewage purification, together with the magnitude of the interests involved and the curious vested interests which have grown up, explain the generation of the atmosphere of prejudice, through which all efforts at improvement are looked down upon. It has not in the least degree surprised the writer of this notice that, although the first sketch of the new method of treatment dates back to the year 1899, the first opportunity of practical application on the large scale did not arise before the year 1903, when the waterlogged condition of the Leek Sewage Farm and the evils attendant on that condition provided the opportunity. At the beginning of the year 1903 the sewage from a population of 8,000 persons, together with refuse from various manufactures, had been discharged upon the Sewage Farm during several years, and at the lower part of the farm a large tract of land was actually under water, which covered a deep layer of black sewage mud. Every day matters were becoming worse, and the necessity had arisen to stop the flow of sewage. January, 19C6.J KNOWLEDGE & SCIENTIFIC NEWS. 319 or, indeed, of liquid of any kind on to the farm. So desperate had the situation become that instead of allowing the fetid swamp to increase the Leek authori- ties might have been obliged to send the raw sewage down the storm overflow into the river and to continue doing so until a partial recovery of the farm had taken place. Under these conditions a chance was offered for the introduction of the new and untried process. The tanks which received the sewage on its arrival at the farm were so small that none of the common processes of precipitation were applicable, but they were quite large enough to admit of excellent work being accom- plished by the new process. The installation of the new process was quickly ac- complished, viz., in three weeks, and the cost was in- significant. On April 3, 1903, the sewage began to flow into the first aerater charged with wood charcoal. On April 11, 1903, the discharge of liquid on to the sewage farm was stopped. Instead of the liquid being run from the tanks on to the surface of the farm and then left to percolate through the land, the liquid was provided with a connecting channel so that it might pass from the upper distributing system of channels into the lower collecting system and into the river without deluging the land. Under the new order of things the Leek Sewage Farm recovered rapidly, the fetid marsh dried up and was ploughed and became cultivated land. The flourishing condition of the vegetables on the farm at- tracted public attention as the summer advanced, and there was a prospect of making a profitable employment of sewage. The quality of the liquid discharged by the Leek Sewers is most variable, and the rate of flow irregular. The Leek water supply contains very little foreign material of any kind, the total solid residue amounting to only six grains per gallon. On Sundays when the sewers do not carry manufacturing refuse, the sewage contains about 60 grains per gallon, some of which is suspended matter, the rest being dissolved matter. The week-day sewage is very different. An average sample, taken on Wednesday, August 12, 1903, was very carefully analysed by the writer with the following results : — Specific Gravity 1001.6. One Gallon contained : — Grains. Organic Matter . . . . 350 Soda Na^O 330 Silica Si Oz . . . . . . 130 Ahimina and Oxide of Iron fi 3 Lime Ca O . . 3-5 Clilorine 8 8 Undetermined . I2'4 Total solid residue .. 112 o The immediate effect of the treatment with charcoal and the action of the aerater was to reduce the solid contents to 90.3 grains per gallon ; and there was a further reduction to 66.0 grains when the eflluent was allowed to deposit its suspended matter. The importance of these results depends upon the care which was taken to ensure that the samples of sewage and sewage-ettluent were true average samples and were strictly comparable with one another. They were the official samples collected by Mr. Farrow, the .Sanitary Inspector, whose trustworthiness and accuracy in m.ilters of this description are proverbial in Leek. Be- ginning at nine o'clock on the morning of Atigust I2, 1903, Mr. Farrow collected a sample once in the hour and continued the work of collection until five o'clock in the afternoon. The nine samples were mixed to- gether so as to form the average sample of the week- day sewage, which was sent to the writer's laboratory by the Sanitary Authority of Leek. In like manner the effluent collected just as the liquid issued from the two small tanks was obtained by Mr. Farrow and sent to the writer's laboratory. The rate of flow through the two small tanks which had been converted into aeraters and charged w'ith wood charcoal was about two-hours ; that is to say, each gallon of sewage issued from the tanks in the con- dition of sewage-effluent two hours after it had entered the tanks in the condition of raw sewage. The alteration in the composition of the sewage during its two hours' sojourn in the tanks and its con- version into sewage-effluent is expressed as follows : — Raw Sewage. Tank Effluent. Specific Gravity .. iooi'o6 .. 1000-82 Total solid contents ) 1120 grains per gallon ) 903 The removal of the 21.7 grains corresponds fairly well with the diminution of density. The tank-effluent was turbid, and on keeping afrest for a period, and afterwards subjecting it to careful decantation it lost 24.3 grains of solid contents, the total solids per gallon having fallen to 66 grains. On August 12 when the average samples were col- lected by Mr. Farrow, the connecting channel was not in use, and it was therefore impossible to collect a sample of liquid at the outfall into the Churnet which would exhibit the degree of purification attainable in the channels in the absence of land treatment. In the next month, viz., on September 9 and 10, the connecting channel was brought into play, and after a twenty-four hours' employment of that channel a sample of effluent was collected at the outfall into the Churnet. The total solid contents was found to be 67.3 grains per gallon. Under the actual circumstances prevailing at the Leek sewage farm these diminutions in the total solid contents of the liquids afford a most satisfactory proof of the accomplishment of the purification. The sub- stances employed in bringing about this purification are atmospheric oxygen, water, and wood charcoal. The purification begins in the two small tanks, and goes on in the long channels (a third of a mile in length) which intervene between the tanks and the river Churnet. The writer of this notice was present when, on April 3, 1903, the raw sewage, laden with a forty-eight hours' acciinuilation of solid excrement, was suddenly turned into the left-hand tank (which had been fitted up with the proper partitions and the requisite charcoal), and he can vouch for the instantaneous and complete success of ^he arrangements. Standing close to the tank he noted that there was no fetid smell whatever, but only a slight odour of soapsuds. Properly applied wood charcoal is, indeed, a most potent sanitary agent ; and the reintroduction of this agent into the working of sewage farms marks the beginning of a new era in sewage-purification. In the year 1903 the writer spent 78 days in Leek and watched over the operation of the new system at the sewage farm. His last visit to Leek w^as on May 2, 1904. Up to that day (being a period of 13 calendar months) the new system was in operation in Leek, and the writer is now in a position to give an estimate of the consumption of charcoal. It is at the rate of one ton per thousand persons per annum. 320 KNOWLEDGE & SCIENTIFIC NEWS. [January, 1906. The DisirvtegroLtion of Saturn's Ring System. By W. J. Knight, LL.D. In his .statuiard work un " Saturn and its S^ystem," Mr. K. A. I'roctor has so hicidly and convincinjfly dis- cussed the disintegration of the rings of Saturn and the consequent and recent formation of the dark ring that subsequent research has done httle more than ratify the conclusions at which he arrived. It is there- fore'to be regretted that he has not extended his in- vestigations to tlie phenomena of the outer edge of the outer ring, where problems of great beauty present tlicmselvos for our consideration. Mr. Proctor remarks that the exterior diameter of the outer bright ring has not perceptibly increased, and suggests a resisting medium as the reason why. I woidd, yyith all respect, prefer to think of the accel- erated satelloids, at the outer edge, being thrown off bodily, like fragments from the rim of a rapidly re- yohing grindstone. The subsequent fate of such a satelloid is full of interest. The paUi it would describe would be that due to the resultant of the three forces acting on it at the moment it started on its separate career, yiz., the force producing its orbital motion, in conjunction with Saturn round the Sun ; the force in- ducing rotation around its primary, and the force of impact. Thispath would lie in a plane but little inclined to- the plane of the rings, but might have any direction in that plane, depending on its instantaneous path at the moment when it left the ring. Dismissing from c.ur consideration all but those trending sunwards, let us follow these tiny planetoids as they trace out their spiral orbits towards the sun. At first inyisible, owing to their small size and great distance, the larger ones become perceptible, when, in the absence of The Giant I'lanet, they succeed in crossing the orbit of Jupiter and are registered in our catalogues as The I^lanetoids, Ceres, Pallas, Juno, Vesta, with hundreds of others of kindred origin. All, however, are not so successful. Attempting the passage near Jupiter itself, the in- fluence of its mighty mass is sufficient to tear them from their independent orbits and to compel them to assume the suljordinate positions of satellites ol Jove. Tile motions of these satellites is direct if they are ar- rested whilst crossing in front of Jupiter, but retro- grade if behind. Possibly the Great Red Spot indicates the fate of one which actually collided with Jupiter itself. -After passing the orbit of Jupiter, the track of the plnnetoids was clear until they approached the orbi; of !\Iars, which thev appear toi have done quite recently, tw'o, Phobos and Deimos, assuming the role of .Marsian Moons, and one. Eras, passing within that orbit and holding out to terrestrial observers the possi- ble acquisition of a second Moon bv the Earth itself. .'\s a confirmation of our theory, it should be ob- served that the orbits of all the planetoids have but a .small inclination tO' the plane of the rings, but we have yet to assign the causes, both of the disintegration of the rings and of the spiral form of the planetoidal (irbits. We take these in order. Saturn, though pro- bably the hottest planet of our system, is yet a cooling body, and the rings, from their extreme thmness and great extent of surface, are cooling much faster than the planet. \\'hat wonder then, since the rigours of .■m arctic winter can split up the crystalline rocks of Spitzbergen, though shielded by the earih's atmo- sphere—what wonder that the fearful cold of inter- stellar space should crumble up the rings of Saturn ? The wonder would be if it did not. Here, then, we have a simple but adequate explanation of this phenomenon. Let us now investigate the form of the orbits of the satelloids after assuming an independent existence. We shall best dO' so by making our observations from the sun, at a time when the plane of the rings passes through it. A straight line joining the centres of sun and planet would then cut the outer edge of the outer ring in a point occupied by a satelloid, which we will call "Quesita." Just prior to impact, the whole sat- urnian system is moving eastward with a velocity just sufficient to* counterbalance the attraction of the sun, but, as Quesita is in inferior conjunction with Saturn, it appears tO' lag behind the planet in its eastward course, and if now it receives an impact from a follow- ing satelloid, it is detached from the ring, is abandoned by Saturn, and left, with diminished velocity, to pursue its eastward path alone. But, as its velocity before impact was only just enough to balance the attraction of the sun, its velocity after impact is insufficient for that purpose, and so Quesita is drawn sunwards. The amount of this disturbance may be small at first, but, as there is no force tO' increase the orbital velocity of Quesita, and as the sun's attraction increases as the inverse square of the distance, the planetoid is con- tinually deflected from its instantaneous orbit and forced to describe a spiral curve, at first differing little from its original ellipse, but becoming more and more inclined tO' it as the years roll on, until it will finally terminate in the sun itself, just as the spiral orbits of the satelloids of the Crape Ring are rapidly approach- ing the body of the planet. As a further corroboration of O'ur theory, it may be noted that recent observations have shown the necessity of applying " corrections " to the elements of Ceres, Pallas, Juno and Vesta. These corrections being required, not because the former observations were faulty, but because, being applied to an elliptic orbit, they failed to give the position of a body really describing a spiral curve. Still, as these helicoids are not greatly different from ellipses through several revolutions of the planetoid, it may be still convenient to calculate their places by means of the approximate ellipse and then apply cor- rections from time to time. CORRESPONDENCE. Magnetism of the Sun. To THE EorriiRs of " Knowledge." Sir, — M. Salet, appointed by the Paris Bureau des Longitudes, to observe the late eclipse, in Algeria, made observations on the magnetic field in the neighbourhood of the sun by observing the amount of deviation in the plane of polarisation of the coronal light. The plane of the bands was found to be deviated in the right-hand direction 2 S. This visual observation was confirmed by photography which showed the plane of polari- sation to be almost radial. The sun, therefore, has very little magnetism. Magnctisable material can be made a magnet by sur- rounding it with a belt of electricity; but if completely sur- rounded by a sphere of electricity there could be no poles and no magnet. This is nearly the case with the sun, the electrical activity of which is nearly equal over its whole surface, and were it not for the slight increase of electricity which pervades the sunspot bands, it would have no mag- netic force at all. W. Badgley. Exmouth, November 24, 1905. January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 321 TKe Evolxition of the Flou^er. By S. Leonard Bastin'. PART I. Broadly speaking, without tht\ complicated system of organs to which, as a whole, we have given the name round the root stock. Some authorities go so far as to say that the Lesser Celandine only very rarely pro- duces fertile seed. Numerous other kinds of plants are also able to propagate their kind by root increase, runners, and such lik<'. methods. But, as any florist is only too well aware, these processes are only realh' ex- tensions of the original parent, for new individuals we must look to the seed. This brings us back to the all- important flower, and it will be the endeavour of the present paper to try to show by means of natural THE P/EONY.^Ii of this flower, it is often seen that the sepals resemble leaves. flower, the blossoming plants could not continue to exist. With certain exceptions all the host of diversely formed plants which produce flowers arc solely and entirely dependent upon the offices of the floral organs for the peipetuation of their kind. Some species, it is true, seem toi be able to flourish and increase apart from the services of the flower — for a time, at any rate. \ notable instance of this may be cited in the case of the Lesser Celandine (Riinunculus ficaria), in which plant a great deal of the increase is carried out by means of the small tubers which are to bo found thirklv clustered examples in what this indispensable body of organs had its origination. It may be of interest to refresh the memory regarding the number of parts which go to make up the typical flower. Starting from the outside of the bloom wc lind the calyx; this consists of a number of sepals which may be green or coloured. Enveloped in the calyx is the corolla formed of a number of petals usually coloured to a gre:itcr or less degree. In the centre of the flower we find on the outside a certain number of the pollen-producing stamens, whilst in the middle of 322 KNOWLEDGE & SCIENTIFIC NEWS. [January, 1906. all is the oroiip of carpels which £jo to make up the pistil. For the present purpose it will be all sufticient to think of the flower as consistini; of these four parts— calvx, corolla, stamens, and pistil. As well, in not a few flowers, there are present a number of appendages to wliirh has been sjiven the name bracts. MOON DAISIES.- It is interesting to note the manner in whicli tlie leaves become more like tlie bracts as they approach the flower. As has Ijeen stated, the calyx of the flower is some- times green and sometimes coloured. This is equiva- lent to saying that the sepals on occasion produce chlorophyll, and in this condition they, of course, carry on the functions of an ordinary leaf. This being so it is interesting to see whether it is possible to discover any relation between the sepal and the leaf other than the fact that both indicate the presence of chloro- phvll. In this connection the case of the ordinary herbaceous Pa^ony is very noteworthy. If a number of specimens of this flower be examined it will be found that quite often the sepals of the calyx are really modi- fied leaves. Indeed, time and again it is impossible to determine definitely the exact nature of the organs, and the confusion is all the greater when, as is often the ca.se, a large area of the leaf-like sepal is as gaily coloured as a petal. The common Moon Daisy of the meadows {Chrysan- themum lauanthcmuni) re\eals in the nature of its growth the whole course of the evolution of the green bracts which encircle the mass of ray florets. Gather one of the long-stemmed blossoms, taking care to pluck it with as many of the lower leaves attached as possible. Now, starting from the bottom of the stem where there is nothing but the typical well-developed leaves of the species, allow the eye to travel upwards towards the flower head. With every fresh stage in the approach to the top there is a notable decrease in the size of the leaves. Finally they lose their distinctive form alto- gether, until just below the flower the leaflets drift into simple lobes, which bear a striking resemblance to the green bracts which form such an important part of the flower head. XLuncrous instances might be noticed in which it would be clearly .seen that we shall not be far wrong in assuming that the green sepals of the calyx arc really nothing more than advanced leaves. But these sepals are often as g.iily coloured as the petals them.sclvcs, bring entirclv devoid of the green tissue which is present in the leaf. In certain sp<"cies, such a.s the Campanulas, the sepals and petals are actually joined together to form one big bell-shaped corolla. Under these circum- stances it may not be amiss to consider for the time being both the floral appendages, whether sepals or petals, as one and the same thing. The common garden Tulip is a well-known examolc of a flower in which the petals and sepals arc identical ; at any rate, as far as the ordinary obser\er cm say. Now if we observe a large number of cultivated Tulip blossoms we shall certainly find that in not a few some of the sepals — that is to say, the outside circle of ap- pendages— are partly or wholly g-reen, proving' beyond a shadow of a doubt whence they have their origin. This is especially so in the case of double Tulips, and the reason for this is probably owing to the fact that the double flower is a more artificial form of Tulip than is the single variety. It is well known that the more highly cultivated and artificially specialised is a plant the greater is the tendency to variation and reversion to earlv tvpes. Moreover, in the Tulip, just below the TtLIPS. -In double varieties of this (lower the leaf origin of the is very apparent. flower a strange leaf-like appendage is often produced, and the intelligent observer will readily see in this a kind of half-way hou.se between the leaf and the .sepal. Perhaps a .still more striking proof of the leaf origin of both petals and sepals is to be seen in the flower of the Summer Sno\\flake [Leucojum cesiiviim). Each January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 323 portion of tin- perianth is tipped with a (int of pure green, and tliis spot stands out in \i\id idiitrast to the snowT wliitcness of the rest of the organ. For \vh;it special purpose this conspieiious marking of green may have been retained it is not easv to sav ; it is all sufli- fient, hnux-\er, to show to the student tile leaf ancestrv of the sepals and JH-lals. all of a green colour. If examined closely they are seen to he nothing more than diminutive Iea\es, and they even go so far as to retain the toothed edges which are so familiar a feature of rose foliage. The change of the leaf into a coloured sepal or petal is not, after all, very remarkable, for coloured leaf-like org.ans, which really exhibit their character in e\erv A splendid South Anioricaii species with show \ bracts. \\\' can liiid at U'ast one exam|ile belonging to an aihaneed laniily which has not found it ne<'essar}' to produce any coloiu'ed sepals or pet.als for its flowers at all. The (ireen Rose (Rusci 7'irii/is), a curious variety ol the China Rose, is, as its name suggests, entirelv without an\ coloured blooms. Vet this flower is possessed of .1 number of sepals and petals, but they are resjx'ct exct'pt that thev are not green, are not at all uncommon. One of the most striking plants exhibiting this change of coloin" in the leaf is .1 South American species, Boiigaiiri'illca glabra, specimens of which are fairly often grown under glass in this country. The real flower of the Boiigaiwillea is a small yellowish blossom, of a much duller hue and nothing like the 324 KNOWLEDGE & SCIENTIFIC NEWS. [Jam'ary, 1906. slrikinsj appearance of our Cowslip. These are pro- duced in clu.sters of three, and would scarcely be notice- able amongst the foliage were it not that each cluster of blooms is surrounded by three conspicuous bracts. These bracts aie exactly in the form of leaNcs, but are coloured in a highly attractive tint of bright lilac. Pre- sumably this strange dcvt'lopment is to attnict the atlentio'n of insects, as a Bougainvillea in full bloom is an object which would be conspicuous from a consider- able distance. In much the same fashion Brazilian Euphorbia (Poiritsc/Zia pulchcrnma) has been able _ to call attention to its green flowers by surrounding these with a circle of bracts coloured with the brightest crimson. In each of the cases mentioned above it is impossible for the student to determine definitely whether the bracts mav be referred to :is k'aves or p.tak. THE SUMMER SNOWFLAKE.— In this flower the leaf origin of the petals and sepals Is easily discernible, each organ having a green spot. ;\ more familiar plant than either of the showy exotics referred tO' is the Salvia hrrnmium rubra, a common garden species. This plant has seen fit to resort to extraordinary means to advertise its small labiate flowers. When the Salvia is in bloom the terminal Icives of each flowering spike are coloured in the brightest pink. That these are true leaves is verv evident frcmi the fact that as one proceeds down the stem it is possible to find leaves which are half green and half pink, until one arrives finally at the whollv green leaves. A further remarkable proof of ihr fan that the petals and sepals of the flower ha\e their origin in the leaf is to he seen in the case of such a species as the Christmas Rose. This plant, as is well known, produces white blossoms during the winter time. What one may call the corolla of this flower is peculiarly tenacious in re- taining its position on the stem, even after the essential organs of the flower are p;ist their maturity. This corolla is really made up of petal-like sepals', the real petals being small processes scarcely distinguishable from Ihe stamens of the flower. But the curious part about these white sepals is the fact that when the flower is " over " they do not fade away as one might expect, but gradually lose their whiteness and eventually be- come green and leaf-like in appearance. Much the same process goes on in the case of the Hydrangea and its show v bracts. Of course, it is well known that the attractive part of the Hydrangea heads of bloom are merely showily coloured bracts surrounding inconspicu- ous flowers. These bracts remain long after the real flowers have faded, and gradually lose their colour, finally becoming as green as the leaves of Ihe plant itselfl Moreover, there are many species of plants in which the coloured parts of the flowers gradually develop from very green materi.al. This is seen in the case of some of the (iuelder Roses {Viburnum). As a matter of fact, in many species the undeveloped sepals and petals practically perform the offices of leaves during the early stages of their existence. Numerous instances might be cited in support of the examples given above, but these would be little more than a reiteration of similar facts. Regarding the evolution of the sepals and petals of the flower from the leaf the case is surely a proven one beyond all doubt. (To be continued. ) Star MaLp. No. 7. Virgo, Corvus. Centavirus. The important features included in this map are the first magnitude star Spica and the Southern Cross. The objects of special interest are not numerous. 27 Hydra- (X h. 20 m. — 18'^'). A planetary nebula. Spectrum gaseous. 7 Virginis (XII h. 37 m. — 0° 56'). A binary, distance apart 5"74. a Virgims (Spiea) (XIII h. 20 m.— 10° 40'); i-2 magni- tude. Shown, by the movement to and fro of the lines of the spectrum, to be a binary with a small or feebly luminous companion. w Cciitauri (XIII h. 21 m. — 46° 57). A fine star clus- ter, visible as a hazy object to the naked eye. Contains some 6000 stars, of which 125 are proved to be variables. The following are the Lecture Arrangements at the Royal Institution, before Easter: — A Christmas Course of Six Illus- trated Lectures, adapted to a Juvenile Auditory, by Professor H. H. Turner, on "Astronomy." Professor E. H. Parker, Three Lectures on Impressions of Travel in China and the Ear East ; Professor William Stirling, Six Lectures on Physiology Subject; Dr. J. E. Marr, Three Lectures on the Influence of Geology on Scenery (the Tyndall Lectures) ; Rev. Canon Beeching, Two Lectures on Shakespeare ; Mr. Benjamin Kidd, Two Lectures on the Significance of the Future in the Theory of Evolution ; Mr. H. B. Irving, Two Lectures on the English Stage in the Eighteenth Century; Mr. Francis Darwin, Three Lectures on the Physiology of Plants; Professor B. Hopkinson, Three Lectures on Internal Combustion Engines (with Experimet:tal Illustrations) ; Mr. J. E. C. Bodley. Two Lectures on the Church in France ; Mr. J. W. Gordon, Two Lectures on Advances in Microscopy; Mr. M. H. Spielmann, Two Lectures on George F'rederick Watts as a Portrait Painter; and Professor J. J.Thomson, Six Lectures on the Corpuscular Theory of Matter. The Friday Evening Meetings will commence on January ig, when Professor J. J. Thomson will deliver a Discourse on Some AppUcations of the Theory of Electric Discharge to Spec- troscopy. Succeeding Discourses will probably be given by Professor S. P. Thompson, Mr. H. F. Newall, Mr. W. C. D. Whetham, Dr. K. Caton, Dr. Hutchison, Sir Andrew Noble, Bart., Professor P. Zeemanr;, Mr. W. B. Hardy, and other gentlemen. Supplement to "Knowledgb & Scientific News," Ja/iunrif. litOG. MAP No. 7. HRKJMTNESS. 1st Mas. 2nd ,, Mil ,, MAP 12 .sill .. 6th ., \aiiabk- Nehiila. MAP No. 7. Virgo, Corvus. Centaurvis. January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 325 A Simple HarmorvograLph. By Charles E. Benham. There is a well-known modification of Wheatstone's Kaleidophone, in the form of a piece of clock sprint;, twisted so that it is divided into two sections, the Hat surfaces of which are at right angles to each other. A bright bead is affixed to the top, and the spring is held firmly in a vice. (Fig. i.) When thus gripped at ap- propriate places the two planes of the twisted spring, being at right angles to each other, communicate to the bead when they vibrate harmonious cur\c movements, ^wf^ G^.cl which are re\ealed to the eye when a beam of light falls on the bead, the reflected point of light becoming by the persistence of vision a luminous track. Hitherto, however, no attempt appears to ha\e been made to render this simple harmonograph self-record- ing. The luminous track has, indeed, been photo- graphed, but the trouble involved makes it hardlv worth while to adopt this method of registering the curves. As a matter of fact, it is an extremely simple thing to make the spring record its own movements either with a light glass pen, or with a line point on a smoked sur- face. If in place cf ihe bead in I'ig. 1 llie spring were surmounted bv a Hat lop, it is clear that a lever pen, resting on that surface, w ould describe the curves there, but the dillicultv would be to make the pen rest iighlly enough to avoid disturbing the movement, and vet rest lirmly enough not to boimcc with the rapid vibr.ilion. .Such a lever is, however, quite practicable, and it will be found most satisfactory to attach it to the spring itself, the recording being done on a stationarv surface. In place of the bead a cork is affixed quite firmly to the head of the spring, and to the flat upper surface of the cork is affixed by two pins a pear-shaped piece of paper of the shape and size shown in Fig. 2. The paper must lie fairly stiff; ordinary writing paper of good quality answers as well as anything, and it is important to preserve the cut-out piece free from bends or creases in any part. The narrow end is attached to the cork, and near the other end a very fine needle point, about half an inch in length, is passed through the paper vertically so that the point projects about one-eighth of an inch beyond the lower surface. The top of the needle point should have been previously warmed and headed with a drop of sealing wax, and when the needle has been inserted in position a lighted match applied near the sealing wax head will cause the wax to melt and run down the needle to the paper, thus cementing the needle firmly in posititjn. The paper lever, with the point at one end and the pins affixing it to the cork at the other, is shown in Fig. 3. It should project with a slight curvature from its own weight, and the smoked glass on which the point is to work is supported on a retort stand or in any convenient way so that the height can be adjusted as required. When thus supported the paper strip should stand horizontal. This delicate recorder, while firm enough for the pur- pose required, is sufficiently light and unresisting to register without seriously impeding the movements of the spring, and with careful manipulation it is free from anv tendencv to rebound. The smoked surface for the tracings niav be a cleaned plate of glass which has been Hooded with Ijenzoline and drained at the corner, taking care, of course, not to bring the benzoline can near the tlame. It should be smoked with a quick movement in the flame of a candle, not too heavily, but until the surface presents a uniform darkened coating of carbon. This film, being very slightly adherent to the glass, will take the finest lines and there will be no undue friction. .\n enamelled sur- 326 KNOWLEDGE & SCIENTIFIC NEWS. [Januakv, 1906. face card may also be used, smoked in the candle flame, taking care to keep it moving so thai the surface is not actually burned. The card or glass is laid on a small flat board, supported on the ring of a retort stand or other convenient adjustable support, so that it can be raised exactly to the height of the recording needle. The spring ha\ing been fixed in the vice so that it is Harmony 1 : 3. in tune, i.e., so that when \ibrate(l the light on the pin heads shows a curve of harmony, retaining its initial phase, the end of the paper strip near the pen is lifted with the tip of a paper knife so that it is just above the paper, and, keeping it thus supported, the spring is drawn gently in a diagonal direction and released, the paper knife being withdrawn at the same moment and Harmony 1 ; 4. the curve of harmony is described on the smoked sur- face with almost magical rapidity. The paper strip must be lifted always by the extreme end and never unnecessarily high, or the " spring " of the paper may gradually be modilied and the needle will not fall pro- perly. The same thing may occur if the strip becomes bent or creased, but with moderate care these dangers are easily avoided. Harmonies from four to one down- wards may be obtained from one and the same piece of spring by gripping it at different intervals in the vice. Unison and approximate unison figures are obtainable with a straight wire in place of the twisted spring. Great accuracy is desirable in ensuring a perfect harmony. The curve shown by the bright pin heads should, in a harmony, retain its pha.se throughout the movement as nearly as possible, and it will be found that a very little movement up or down of the spring is sufficient to throw it into discord or bring it iiito har- mony as the case may be. The harmony should, of course, be secured with the lever in position working upon plain glass or paper, as the weight of the pins and paper strip has to be taken into accoimt. The different phases of the same figure are rendered by the different directions in which the spring is started, ^\'hen once Harmony 3 : a. the various harmonies have been found they may be convenientiv marked in ink on the spring by a line at the position where it has to be held by the vice. The length of the spring above and below the twist will, of course, depend upon the size of the spring. An ordinary piece of clock spring of about twelve inches length twisted at the middle will be found to answer. The smoked tracings may be fixed by pouring a thin spirit varnish, much diluted with spirit, o\er the sur- face, and the glass tracings thus varnished can be used as negatives to print from photographically. To execute the tracings in ink a fine capillary tube is substituted for the needle. It is made in the same way as the ordinarv harmonograph glass pen, bv drawing the tube to a point, sealing and grinding down till the hole is reached; but only the tip of such a pen must be used, so that after it has been made the end must be cut off — about half an inch, and this is fixed with seal- ing wax through a hole in the paper strip in place of the needle. -A tiny piece of cotton wool or worsted is inserted in the top opening, and the pen is filled with a small brush with violet or other dye, the supplv being generally enough for at least 20 figures. January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 327 WKslI is qlI the Centre of the Eacrth? We happen to have receivod recently tliiee different articles bearing on this subject, and, considering the interest, the mystery, and the importance of the ques- tion, we think it desirable to publish them in series, and hope they may elicit comments and criticisms from other writers. It seems remarkable that though we are able to in\estigate the composition of stars millions of miles away, and though (with the exception of a few com- parativele absent. I find it is also absent to me. On careful examination I find that the pictures for both eyes are printed in both colours — that is, each eye, using the coloured spectacles, sees parts of both red and green, but not the same parts. The distribution of colour is systematic throughout, and a conspicuous example will show the character of it. A shop front in the foreground has white sash bars in front of a dark interior, and over the front the name is in dark letters on a light ground. The picture provided for the one eye and the picture that is really seen by that eye, has green sash bars and red letters. The picture for the other eye has red sash bars and green letters. The sash bars are light on a dark back- ground, and the letters are dark on a light background. Therefore the representation of objects bv such means is not a simple case of printing' the one picture in red and the other in green, and discriminating them bv means of spectacles with one red and one green eve. This simple and straightforward method must, I think, be faulty, and success appears to depend on a distribu- tion of colour by hand. If it is so, these productions cannot rightly claim to Ix.' photographs, and the method is not useful for scientific purposes, as it might other- \\ ise be. 330 KNOWLEDGE & SCIENTIFIC NEWS. [January, igo6. Answers to Correspondents. Ignoramus. Altitude of the Sun. Many books on Practical .Astronomy define the terms used, though not in a very explicit manner. Perhaps the following may make it clear to you :— The altitude of the sun is the angle at the observer's eye between the sun and the horizon. The dultnatwn of the sun is the angle between it and the Equator (produced). The declination at noon each dav is given in any astronomical ephemeris ^i'i./<■ " Science Ve.ar Book "). Therefore, knowing the declination, one can find the altitude at any given latitude by subtracting the latitude from go', and uddint; the declination if summer, or suhlnicliii^ it if winter (when sun is south of Equator). Thus, if latitude 51° 28', Deducted from 90° = 38"' 32' ; Declination at noon January 1st = 28= 3'28" ; .-. altitude - 10° 28' 32". The following diagrams explain this, where A is the position of the observer. Since the sun is at a comparatively infinite distance, the altitude will be practically the same at O (centre of the earth) as at A. Tben in fig. 2, \ O E is a right angle, as is A O II. Deducting the common angle A O E (= the e^-y—i latitude), we have N O A (= 90^ - latitude) = E O H, and E O H + Declination is the altitude. This, of course, is the principle for finding one's latitude at sea. Observe (with a sextant) the altitude of the sun above the horizon, add or de- duct the declination las given in tables), and deduct the result from 90-. This gives the latitude. Cecil Evans. Though we have referred your letter to several authorities, we fear it is not sufficiently explanatory for us to comprehend your meaning. G. P. Blake. Remember that the obliquity is not constant. It is diminishing nbotit o"4 annually, though the e.xtiet diminu- tion can only be surmised by theo'ry. The change should not be " put down to precession." To Ma.ke Iron Grow. The Franklin Institute has awarded the Elliot Cresson Gold Medal for a new process by which iron can be made to grow. This consists in heating and cooling the bar of iron which it is intended to magnify to a " critical " temperature a number of times. The results are extraordinary. To the Mechanical Science Section of the American .Association two bars of iron cast in one mould were presented for critical inspection. One bar remained exactly as cast. The companion bar had been caused to grow gradually in cubical dimensions till it is now 46 per cent, larger than the other, the weight remaining the same as before expansion. Both bars were machined on one side to show the texture and metallic appearance ; and it was difficult to detect any change except the very apparent difter- ence in size. It is said that important practical applications ha\e already been found for this remarkable discoverw ASTR.ONOMICAL. By Charles P. Bltler, A.R.C.Sc. (Lond.), F.R.P.S. Diffraction Grating R_eplicas. I'~oK some years past both physicists and astronomers have been using the excellent Diffraction Grating Replicas made by Mr. T. Thorp, of Manchester, and now he is able to make the interesting announcement that he has been successful in pro- ducing coiteave replicas. There will be a very great field for the application of this form of spectroscope, which is self-contained and needs neither coUimating nor telescope lenses. At pre- sent the replicas are only of plain celluloid, but experiments are in progress for silvering the diffracting surface, when the brightness of the spectra will be greatly enhanced. .\nother distinct advance is the making of the grating films on glass rings, so that there is no glass for the light to pass through, and these will be very useful for investigations of ultra violet radiations. Possible Relationship between Light and Velocity Variations of Variable Stars. In a recent paper by K. C. Curtiss the author points out an important coincidence which he has found to exist between the variations of magnitude and radial \elocity of the variable star W Sagittarii. When these were plotted it was at once seen that there was a most striking concordance, the two curves corresponding not only in general form, but in most of the minor inflections. The light maximum, according to the latest values, occurs o'gg day after periastron, and almost exactly at the epoch of velocity minimum. Comparing the most recent photometric measures of the light variation, from the Harvard College Observatory, with those made by Schmidt some thirty years previously, there are seen to be numerous differences, and it seems not improbable th.at these may be more or less due to actual changes in the system of this star during the interval which has elapsed between the two series of observations. New Views about Comets. Various novel facts concerning the formation and appear- ance of the tails of comets have recently been described by Professor Barnard, the discussion of which leads him to think that the views generally accepted may have to be consider- ably modified in future. Although no explanation has been definitely found to cover all the many details exhibited bv the growth and dissipation of a comet's fail, that of Bredechin has probably received most favour. This ascribes the varying forms of tail to dif- ferent constitution of the matter evolved from the comet, on which the resulting effects of the sun's repulsive force will be to produce streams of cometary matter extending in curves of varying degree, depending on the density or other physical properties of the substance. In this and most other theories it has been customary, however, to ascribe practically all the cause of the phenomena to the action of the sun, supposing the comet to merely supply the material to be acted upon. During the last ten or twelve years, however, the applica- tion of photography has resulted in the discovery of many new features which are rather of a revolutionary nature, and are not easily explained. Professor Barnard now thinks that three main causes are at work. First, the sun, which produces in the nucleus of the comet a disturbing action, and which influences the general direction of the tail-producing particles. Second, the comet itself, in which a strong ejective power seems to be located. This is proved by the frequent formation of straight minor tails or streams of particles which are often seen to issue at large January, igo6.] KNOWLEDGE & SCIENTIFIC NEWvS. 331 angles to the general direction of the main tail. Such peculiari- ties are quite contrary to the effect produced by the sun. In many cases it would seem that this emissive power is great enough to entirely overcome the direct pressure of the sun's light. Not only this, but the sun's light appears to have no bending effect towards the radius vector, as might be ex- pected. Third, an outside influence quite apart from the comet, which is shown by the many rapid distortions and deflections of the tail. There appears to be clear evidence that this is some sort of resistance offered by a kind of medium not uniformly distributed in the planetary spaces, as, for instance, a meteor swarm. Encounters with such a medium would readily explain the sudden brightening up of some comets when long past their theoretical maxima, as was shown by Sawerthal's comet in May, 1S88, or it might account for the breaking up of such a comet as Biele's. It would seem that something of this nature was chiefly instrumental in producing the special peculiarities of the tail of Brook's comet in October and November, iSgj. Photographs taken by Barnard on November 3 and 3 show most remarkable changes, and these are strikingly shown in a composite picture madeby superposing the two plates star for star, giving the two positions of the comet with 24 hours' interval. There is a difference of nearly 15 between the directions of the tail in the two cases, while it is remarkable that the position of the ends of the tails do not appear to have materially changed, and various portions are seen to be detached from the main stream. Basing on these evidences of quick change a suggestion that every active comet should be photographed as often as possible, he points out that this might with advantage be done hour by hour during every night, as by this means the actual changes in any part of the cometary matter might be followed with certainty, and it may be possible to determine the exact value of the motions of the particles in the tails of various comets, or the same comet, at different distances from the sun, and so give the true law of the velocities of these particles apart from any theory. It seems then more likely that the difl'erent tails of a comet are all made up of the same kind of particles, and the cause of their different directions is that they are ejected towards different parts of space by a force residing in the comet itself. The evidence of the spectroscope, so far as it goes, has certainly not shown them to be of very diverse elements. CHEMICAL. By C. .AiNswoKTH Mitchell, B.A. (Oxon.), F.I.C. Acetylene Bla^ck. The old method of obtaining a black pigment for printing mk was to conduct the smoke from burning wood, oil, or resinous substances into a cylindrical chamber in which were hung sheep skins or sacking. An inverted iron cone was suspended from the top of the chamber, which it fitted so exactly that when lowered its edges scraped the suspended sacking and removed the black deposit. There arc numerous other methods based on the same principle, such as, for instance, that claimed in a recent U.S..\. patent, in which sevi-ral oil lamps are burnt beneath a IioIIdw cylinder through which passes a current of cold water, the deposit of lampblack being removed by a fixed brush as the cylinder revolves. However carefully prepared, lampblack invariably contains more or less tarry oil, which being yellow detracts from the depth of tone, and the usual method of removing this is to calcine the black in closed iron boxes with only a small opening for the escape of impurities, every precaution being taken to prevent the admission of air. The discovery of natural gas in various parts of the L'nited St.ites put a cheap source of bl.ack at the disposal of the maker of printing ink, and led to the .\nieri- can inks acquiring a high reputation for depth and richness of tone. The gas issues from borings 2000 feet in depth, and is burned in jets beneath revolving iron rings, on the surface of which the black is deposited, about 1000 cubic feet of gas being cousumed in the production of i lb. of gas-black. The product is much purer than ordinary lampblack, and in the crude state contains 92 to 93 per cent, of carbon, 5 to 6 per cent, of oxygen, i to 2 per cent, of hydrogen, and traces of mineral matter. Its tinctorial power is also much higher, and it requires less purification than lampblack. A still purer and more intense black has recently been prepared by Ur. Frank by exploding a mixture of acetj'lene with carbon monoxide or dioxide, and it is claimed that this product is superior to the best American gas-blacks both in quality and covering power. On the other hand, its cost is likely to be greater than the American blacks, which at the present time fetch about 3d. or 4d. a pound. Water from the Simplon Tunnel. In the course of the construction of the Simplon Tunnel numerous springs were encountered, and the water from one of these, about five miles from the Italian end of the tunnel, has been analysed by Mr. .\. G. Levy. The water, which had a temperature of 113' F. at the point of collection, was clear, colourless, and without smell, but had a saline taste. It con- tained 106-5 grains of solid matter per gallon (about five times that of London drinking water), consisting principally of cal- cium sulphate, with a considerable proportion of magnesium sulphate, and small amounts of other salts. It was quite free from organic matter and also from chlorine, which latter fact was the remarkable characteristic of the water ; since, con- sidering the distance it must have travelled underground to attain its high temperature, one would have expected it to come in contact with soluble chlorides somewhere on its way. Photo-Active Properties of Rabbits' Blood. Experiments have been made by Dr. V. Schlapfer, of the Pathological Institute of Zurich, to determine whether blood is capable of affecting a photographic plate in the dark. For this purpose the fresh blood of albinotic and pigmented rabbits was employed, with and without previous exposure to light, and also after treatment with prussic acid and potassium chlorate. In each case the plate was covered with black paper, on which was placed a photo-neutral capsule of paraffin wax containing the blood. It was found that the blood of pigmented rabbits had a very much weaker effect upon the plate than that of albinotic animals. The activity of both disappeared after some days, but could be restored again by exposure to light. Blood treated with prussic acid was in- variably inactive, whereas that of animals poisoned with potassium chlorate was always active. The slinu'lative influ- ence of light upon the photo-activity of the blood has sug- gested to Dr. Schlapfer a theory to account for the marked difference in the behaviour of the blood from the pigmented and the albinotic rabbits. He considers it possible that in the case of the albino the blood circulating in the cutis may be acted upon to a considerable extent by the light and thus rendered photo-active, whereas the pigments in the skin of the brown rabbit may act as a light-screen and weaken the effect of the rays. GEOLOGICAL. By Edwaku .\. Makti.n, F.G.S. A Twin-Earthquake. Dr. Cuaklls Davison keeps unceasing watch over the various earthquake shocks which are constantly visiting our islands, more frequently perhaps than most people believe. In a recent paper he has described the Doncaster earthquake of .•^pril of this year. He tells us that it was a twin-earthquake, with its principal epicentre half-a-mile north of Bawtry. and the other about four miles east of Crowle, close to the centre of the Ilcssle disturbance of .Vpril, 1902. Last .\pril the earthciuake-area included about 17,000 square miles. He says that a twin-earthquake is probably due to the difl'erontial growth of a crust-fold along a fault which intersects it trans- versely, the first movement as a rule being one of rotation of the middle limb, accompanied by the almost simultaneous slip of the two arches, and followed soon afterwards by a shift of the middle limb. 332 KNOWLEDGE & SCIENTIFIC NEWS. [Janlakv, 1906. The Scuirr of Eigg. At a meeting of the Geological Society held on December 6, Mr. Alfred Harker read a paper on "The Geological Struc- ture of the Sgiirr of Eigg." The mention of this phenomenal mass of pitchstone naturally recalls to mind the very full description which we have had from Sir Archibald Geikie of the island, and the deductions which he has drawn as to the remarkable changes of level which have taken place, and the vast amount of denudation which has resulted in the formation of the Scuir (so spelt by Sir Archibald). The pitchstone is a massive sheet some 400 feet thick, and reposes upon alter- nating basalts and dolerites, which make up the greater part of the island. Beneath the pitchstone there are in two places accumulations made up of fragmentary materials, and these the latter geologist regarded as river-gravels of the age of the pitchstone, which overflowed into the valley of a stream which has since disappeared. The fragments of the gravel have alone been preserved by the pitchstone protecting it from denudation. Mr. Harker is unable to accept Sir Archibald Geikie'sview. He thinks that the pitchstone may have been intrusive, and does not think that its base is reconcileable with that of a river valley. The fragmentary deposit is in one place, he states, a volcanic agglomerate, probably filling a small vent, and the other appears to him as a bedded agglomerate, but this he admits has been re-arranged by water action. There are contained in the deposits abundant blocks of Torridonian and Oolitic sandstone, with fossil wood of Oolitic age, and these are held to have been forced up from below. In this respect there is perhaps some failure of evidence, and some geologists will not regard this explanation as a probable one. It should be added that Sir Archibald adheres to his own explanation of the origin of the fragmentary deposits, and no doubt more will be heard of the matter now that the leading geologists differ radically as to its origin. Pleistocene Lake at the Mouth of the Ta-gxis. At the same meeting a paper was read by Prof. Edward Hull concerning the " Great Pleistocene Lake of Portugal." The margin of the former lake was probably formed by the granite of Das Vargans and Cunheira. Miocene times are thought to be represented by the Almada Beds, and the Pliocene not being represented, except possibly by certain glacial deposits. Prof. Hull thinks that the period was one of great uplift, and this resulted in the excavation of the sub-oceanic gorge which marks the seaward extension of the River Tagus. Thus the lake was finally drained by the Tagus cutting a channel at the harbour of Lisbon, upon the elevation of the land to about its present level. Gla.ciatiorv in Snowdonia. Evidence of the Glacial Epoch are numerous in North Wales, as all acquainted with Snowdonia are well aware. Our illustrations give two well-marked types of scenery. Fig. i shows a fine series of moraine hillocks near the Devil's Kitchen, at the head of N'ant Ffrancon valley ; and fig. 2 gives the rochc-moittonnce appearance of surface-rock resulting from the planing power of a mass of moving ice, taken from the same neighbourhood. ORNITHOLOGICAL. By \V. P. Pycraft, A.L.S., F.Z.S., M.B.O.U., &c. Humming Birds in EnglaLnd. At the meeting of the Zoological Society on November 28, Captain Pam gave a most interesting account of his attempt to start a colony of humming birds at the gardens of the Society, and, though this attempt was frustrated, the greatest credit is due to Captain Pam for the strenuous eft'ort he made to achieve this end. He left Venezuela with about half-a- dozen specimens oiPetasophora iolata, the BoUvian '-violet ears" of Gould's monograph of these birds ; but, unfortunately, onl)' one reached the gardens alive, and this has since died. He fed his birds on a mixture of sugar and meat extract, a diet which seems extremely well suited for these delicate birds, inasmuch as he succeeded in keeping his captives alive, and well, longer than many residents in Venezuela who have continually endeavoured to keep these birds in aviaries, but without success — two months being about the record. Humming birds appear to be late feeders, coming out just when other birds are going to roost. They are also heavy sleepers; so much so that Captain Pam found it difficult to awaken his birds after they had finally retired to roost. They appear to be extraordinarily sensitive to shock, so much so that should the cage in which they are confined receive a sudden jar, they lose their foothold — for the feet are remark- ably small, and but little used — and tumble to the bottom of the cage. Whenever this happens, it results in a total loss of the power of movement in the wings ; the birds become unable to regain the perches, and speedily die. It was believed that this bird was the first humming bird ever brought into this country alive. But Mr. Pocock points out (Field, December 9) that in July, 1S94, no less than eleven specimens of Truchiliis cuniutus were brought o\-er in the ?.s. Silc, and were ultimately purchased by the late Mr. Erskine Allen, of Gray's Inn. It would be interesting to have further particulars of these birds. The Breeding Plumage of Birds. In a very short but extremely interesting article in the FicUl, December 2, signed " R. L., ' a new interpretation is given to the "eclipse" plumage of the Mallard and other Anatidas. It is suggested that the " eclipse " dress corresponds January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 333 to the non-breeding plumage of, say, the Waders, while the brilliant livery worn during the greater part of the year really answers to th3 breeding dress of the Waders, which is worn for a short period only. But for the need of protection dur- ing the period of quill-moulting it is contended the Mallard would have assumed a permment breeding dress, as in the case of the Sheldrake, or of the game-birds for example. Whenever the m.ale birds are brilliantly coloured we may assume, he paints out, that this is a permanent breeding dress, and when the hen stands in no need of a dull protective dress she also assumes a similar plumage. With this interpretation we heartily agree. A New British Thrush. The Field, December 2, contains an account by Mr. T. Whittaly R. Lydekker. Colour Change in Gibbons. How imperfect is still our knowledge of the life-history of many animals has been remarkably illustnited of late by a gibbon from the Island of Hainan which has for some time been living in the Zoological Society's Garden. When re- ceived, and apparently full grown, it was jet black all over; after a time, however, it changed its coat, when, to the astonish- ment of everybody, it came out in a greyish buff livery, the bare skin of the face alone retaining the original sable hue. Probably certain allied species of gibbons undergo a similar colour-change with age, although the Himalayan hulock and the Sumatran siamang are apparently always black. Va-riation in Lizards. .•\ very remarkable paper on the pattern and colour variation displayed by ditTerent phases of the wall-lizard of southern Europe has recently been published in the Transactions of the Zoological Society. How great are the variations in these respects, a glance at the beautiful series of plates with which the paper is illustrated will serve to show. By some authorities these variations have been — and probably still are — considered as of specific importance ; and it is from the boldness with which the author, Mr.G. A. Boulenger, sweeps aw.ay such nominal distinctions that we have ventured to call the paper remarkable in these days of incessant splitting of species and races. " Of late," writes the author, "a tendency has sprung up to greatly multiply the species and thus destroy the old conception of Lacerta muialis. I doubt whether such attempts will conduce to a better understanding of the subject. . . . Characters of form and coloration are given as distinctive which, on examination of even moderately large series of specimens prove to be worthless, while others of greater importance have been overlooked or neglected." Evidently much water has still to 334 KNOWLEDGE & SCIENTIFIC NEWS. [January, igo6. run through the bridges before our conception of what consti- tutes a species, or even a race, can be regarded as finally settled. The Senses of Animals. Several intcrestini; connnnnic.itions ha\e appc.ired during the last few weeks concerning the senses and psxchology of animals. A German authority has. for example, expressed the opinion in somewhat confident terms that fishes are stone-deaf; this view being based on the structure of their internal ear. A discussion on the subject has appeared in the columns of the Fii-ld newspaper, in which several anglers point out that fishes can perceive vibrations, from which it is inferred that they can hear. This is, of course, begging the question, as if the German aurist is right in his contention that fishes laclc the essential parts of the organ of hearing, it is quite evident that vibrations must be perceived in some other manner. A second Continental authority has adduced evidence to show that ants recognize one another by means of the sense of smell, which is apparently located at the base of their antenna-. Finally, a third foreign naturalist, who writes from Costa Rica, is of opinion that there is no difference in kind between the essentially automatic actions of even the lowest organisms and the manifestations of the human will, but that there is a gradu.al transition from one to the other. Ne\v Bats. The study of bats has occupied a large amount of attention during the last few months, and a number of new species and races of the horseshoe and leaf-nosed groups have been named. By far the most interesting addition to the list is, however, a new mastiff-bat from West Africa, since it is a near relative of a group hitherto known only from tropical America. It comes, indeed, very close to the .American Molossiis. although it has been made the type of a new genus — Eoiiiops. Papers R.ea.d. At the first meeting for the k)05-5 session of the Zoological Society, held on November 14. Dr. Kidd discussed the arrange- ment of the fine ridges on the hands and feet of various species of mannnals, chiefly monkeys and lemurs. Mr. Honhote named two new species, and one raceof Tibetan mammals, viz., a fox, a hamster, and a vole. Major Evans communicated notes on the gorals, or lesser goat-antelopes, of Burma ; while Miss Bate gave an account of the mannnals of Crete. At the meeting on November 28 Mr. Lydekker discussed the colouring of the guereza monkeys, and also called attention to a mounted specimen of the little known white-maned serow, or goat- antelope of China; Mr. Thomas exhibited and discu-ssed a collection of mammals from Japan ; and Mr. Kegan proposed a rearrangement of the fishes of the southern family Galuaxiidir. Ai the meetmg of the Geological Society held on November 22 Dr. Smith Woodward described new remains of a species of an extinct genus of Chim;Era-like fishes from the Lias of Lyme- Regis. REVIEWS OF BOOKS. My Life: A Record of Hvcnts and Opinions, by Alfred Rnssel Wallace; in two vols. (Chapman and Hall; price, 25s. net.). — Among the many claims to attention possessed by Dr. A. K. Wallace's autobiography is that of furnishing a sunmiary of most of the controversies which shook the mid-\'ictorian era. It was the day of controversies and of controversialists, perhaps because it was also the day of great generalisations ; perhaps because scientific interests were less decentralised, and what interested one body of scientific workers interested them all. The controversies of to-day between Sir Oliver Lodge and Professor Ray Lankester and Mr. Mallock on Psychics, or between Mr. Hateson and Professor Karl Pearson on Heredity, rouse no such passions as those between the Darwinians and the theologians, or between Dr. Wallace (for example) and St. George Mivart and the other sceptics of Spiritualism. To read Dr. Wallace's record of these great controversies is to experience a sense of intimacy with another generation, as well as with other times. Dr. Wallace is the last of the great controversialists. He was one of the three who "kept the bridge " for Darwinism ; but a controversy even oi that embracing kind was not enough to absorb all his energies. Land nationalisation. Socialism, Spiritualism, and a fierce dis- pute with a fanatic about the configuration of the Earth were some of the subjects du which he argued, wrote, and spoke ; and it is significant of the energy which he put into all that he did that the last named of these controversies — settled by the famous 15etlford Level experiments— gave him more trouble and took up more of his time than any of the rest. The details, the correspondence, and the stages of these contro- versies are all related with great fulness in the two volumes of Wallace's " Life." and would be of the greatest interest and value even had he himself played a less prominent part in them. His position, however, with regard to them is of the first importance. To many people in this degenerate day he is chiefly remembered as the associate of Darwin in what people are sometimes pleased to regard as the •' discovery " of the Darwinian theory. A theory of this kind is never '• dis- covered " ; it must be the outcome of the most patient and long-continued examination, observation, and confirmation of research. If it were otherwise, then L")emoeritus or some of the early Greek philosophers who speculated on the origin of the universe might be claimed as the " discoverers" of Dalton's .'\tomic Theory, or of the Fourth State of Matter postulated by Sir William Crookes, and elaborated as a theory of Professors J. J. Thomson and Rutherford. In such a sense Dr. Wallace might — with much more justice — claim to be the discoverer of the Darwinian doctrine of the origin of species, for the idea came to him as a brilliant flash of inspiration while he was in the Malay Archipelago examining and classifying some of his zoological captures. " At the time in question," writes Dr. Wallace, " I was suffering from a sharp attack of intermittent fever, and every day during the cold and hot fit had to lie down for several hours, during which time I had nothing to do but to think over any subject that particularly interested me. I )ne day something brought to my mind Malthus's • Principles of Population,' which I had read about twelve years before. I thought of his clear exposition of the ' Positive checks to in- crease ' — diseases, accidents, war, and famine — which keep down the population of savage races to so much lower an average than that of more civilised peoples. It then occurred to me that these causes and their equivalents are continually acting in the case of animals also. . . . Vaguely thinking over the enormous and constant destruction thus involved, it occurred to me to ask the question ' Why do some die and some live ? ' And the answer was clearly, ' that on the whole the best fitted live.' . . . Then it suddenly flashed on me that this self-acting process would necessarily iuipvovc the nice, f)ecause in each generation the inferior would be killed off and the superior would remain, that is, the fittest tiouli! sitrvwe." The idea, thus furnishing one of the curious coincidences of science, occurred to Wallace while Darwin was working at it ; but it is none the less to Darwin that the establishment of the great principle on a firm basis is due ; and it is to him, as Dr. Wallace modestly admits, that we must ascribe the name of the real discoverer. In this extract we have touched upon only one facet of interest among the many for which these remarkable volumes are conspicuous. They were written by a man who was intimate with the best scientific intellect of two generations, and who has been generous in relating the points of contact he had with them. An Elementary Text-Book of Inorganic Chemistry, by R. Lloyd Whiteley, F.I.C.; pp. S and 243 (Methuen ; price, 2S. (id.i. — Students taking the elementary stage of the Board of Educa- tion examinations in inorganic chemistry will find all they require in this little book, w hich is too short, howe\er, to include much more than the details essential for this particular pur- pose. It is well printed and illustrated, and gives descriptions of numerous experiments in such a way that students can re- peat them for themselves. Radioactivity. Professor Rutherford (Camb. Univ. Press, los. 6d. net). — The appearance of a second edition of this treatise so soon after the appearance of the first is an event which gives rise to an apology from the author to the purchasers of the first edition. However, so rapid and extensive have been the advances made in our know- ledge of the subject, that everyone will concede that no apology is due. The present edition is \u all intents a new book, although it is based upon the old one. Besides a re- arrangement of the whole, three new chapters have been January, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 335 added, which give a detailed account of the theory of suc- cessive'changes'and of its application to the analysis of the series of transformations which occur in radium, thorium, and actinium. The' disintegration theory, about which there was much misgiving in many minds, still holds its ground as the most effective of all theories in co-ordinating the multitudinous experimental data which are known, and as pro\ iding a most powerful and valuable method of analysing the connection between the series of substances 'which arise from the trans- formation of the radio-elements. ' Many of the results of the researches during the past year have already been noted in this Journal : and it will be recalled that for these results Pro- fessor Rutherford is himself largely responsible. From the beginning, when facts were few and theories conflicting, he seems to have been marked out as the man possessing just those qualifications required in a pioneer investigator — viz., fertility of resources, and an adequate endowment of what many would call crudeness, which enables a man to go for and seize the main outlines of a subject while others are groping in the dark after irrelevant minntia;. The result is a magnificent achievement; and everyone will welcome this fresh summarisation of the present state of knowledge by one from whom so much of it has come. We cordially com- mend this book both to the expert, to whom the possession of it is a necessity, and to the amateur reader or speculator, who. it not already acquainted with it, will be surprised at the ease with which it will enable him to enter into a real know- ledge of this fascinating subject. Instruction in Photography, by Sir William .Abney (Iliffe and Sons; price 7s. 6d. netl. — The fact of an eleventh edition of a book being published is in itself a complete proof of the value and usefulness of the work. Abney's " Instruction " has before now been aptly termed " a photographic classic," and contains all that an amateur, or professional either, should know. We should not like to go quite so far as to say that what is not in this book is not worth knowing, but it is safe to say that any matter omitted is beyond the scope of the ordinary photo- grapher. Both the theory and the practice of this subject, which is now becoming so greatly enlarged, are carefully gone into. Besides considerations of the action of light on silver compounds, tlie development of the resultant image, the theory of len.ses and stops, the preparation of gelatine and other emulsions, we have information on transparencies, enlarge- ments, and copying. There are descriptions of the various modes of printing and preparing sensitive papers, as well as such more elaborate processes as photo blocks and three-colour printing, which latter especially has been considerably enlarged in this latest edition. British Rainfall, 1004, compiled by Hugh Robert Mill, D.Sc., &;c. (luiward Stanford; price los.). — This annual, .so indis- pensable to all meteorologists, is a most complete collection of statistics relating to rain. Pari I. contains a report touching on the work of " The Rainfall Organisation " — that is, the organisation for observing and recording rainfall ; original articles on the r.iinfall on ISen Nevis ; the driest October on record; and twenty-four years' records. Tables are given of the duration, lS;c.. of rainfall; and accounts of the staff of observers, &c. Part II. deals exclusively with 1904, with dis- cussions on the special characteristics of the year. The book is well got up, and contains a number of excellent maps and charts. The System of the Stars, by .Xgnes M. Gierke. Second edition (A. and C. Black ; price 20s. net).— It is already fifteen years since the first edition of this work appeared, and, as a result of the progress which the science of astronomy has undergone during that period, very extensive additions and corrections have become necessary. .Xmong othc'r features a number of excellent reproductions of photographs are now included, which add greatly to the interest of the book. Astronomers, and especially amateur astronomers, will wel- come this up-to-date account of the stellar imiver.se, resting assured th.it the inforiuation given is accurate and complete, as well as the style and wording being attractive. .\s the author remarks in the preface, " literary treatment is the foe of specialis.ation," and that literary treatment which renders clear and inviting the mysteries so often hidden beneath a load of abstruse phraseology is to be encouraged. We would .advise those ordering the book to insist on the pages being cut before delivery. Quiet Hours with Nature, by Mrs. Brightwen (London : Fisher L'nwin). — This little- book is probably one of the best that Mrs. Brightwen has written. Herein she discourses on many sub- jects— beasts, birds, and beetles, trees and gardens. Wide as is the range of these pages, yet nowhere are they dull ; on the contrary, there is a sparkle in them that is refreshing, espe- cially when one recalls the twaddle and crude inaccuracies that pass nowadays for '• nature-study," and find favour with those who are supposed to possess a nice discrimination in the choice of books for the young. This volume is one which we hope will be largely read. The photographs from nature are charming, but many of the original drawings are, to say the least, unsatisfactory. Wild Wings, by Herbert K. Job (London : Constable and Co. ; 11)05). — This book is unquestionably .a valuable contribu- tion to ornithological literature. Though entirely concerned with the ways of wild birds, many of which have been (racked to their inner fastnesses, it contains many facts that will throw light on the deeper problems of evolution and systematic ornithology. The author displays not only a wide knowledge of his subject but a rare discrimination in the selection of his facts, a combination which is all too rarely met with in the books of recent writers on this subject. Artists should find this book a boon, for the illustrations, which are numerous, may be described in many cases as superb, while their general average is far above that which we are accustomed to meet with. W. P. P. Trees, by H. Marshall Ward, Sc.D., F.R..S., &c. ; Vol. III., Flowers and Inflorescences (Cambridge: The University Press; 1905). — If the series of volumes on trees which Dr. Marshall Ward has set himself to write do not exactly furnish exciting or fascinating reading they will prove a very present help in time of trouble. This volume, like its predeces- sors, is in every way admirable. To the working botanist it will prove an indispensable companion, while to those who are desirous of taking up this study we cannot recommend a better book. To tliese last, probably this book would appear on a casual examination too technical, but a very slight acquaintance with its contents will show not only that this impression is quite erroneous, but that here, as in few other similar volumes, they will find a key to mysteries and delights which they had probably never suspected. The author calls special attention to a feature of this volume which should prove of value to the forest botanist. This is a supplementary (able of classification, by means of which that most difficult of groups — the willows — may be distinguished by characters derivable from staminate or from pistallale tlowtrs respec- tively. The illustrations which are profusely distributed throughout its pages are extremely well chosen, and many are of great beauty. We have received from Messrs. Newton and Co. their latest catalogue of Optical Lanterns and Slides. This includes a marvellous collection of views of all sorts and kinds, but we would especially notice the complete series in astronomical and ill physical subjects. .\nother novelty has recently been introduced by this firm and may be seen at their establishment in Fleet Street. It is called the " Sympathetic Pemlulums," and consists of two weights suspended by springs from a bar of wood. When one weight is pulled down and released, it vibrates up and down for a certain time, but then seems to impart its motion to the other weight which starts bobl)ing up and down, while the first rests perfectly still. Hut in due course the second weight comes to rest and the first again starts its motion. We have received, among others, an interesting catalogue of Meteorological Instruments from Messrs. Pa.storelli and Rap- kin, with e 40™ ; Dec. S. 19" 28') appears in close proximity to the Sun, and is practically unobservable. Mars (Jan. i, R.A. 22i>24-"; Dec. S. 11'' 2'. Jan. 31, R.A. 23'' 48'"; Dec. S. 1° 50') is an evening star in Aquarius, and appears in the sky a little to the east of Saturn. Near the beginning of the month the planet is on the meridian about sunset, but in consequence of now being at a great distance from the earth he appears but a feeble object. Jupiter (Jan. I, R.A. 3h 40m; Dec. N. 18-41'; Jan. 31, R.A. 3^ 36"^ ; Dec. N. 18'' 41') is due south at 8 p.m. near the middle of the month. The planet is describing a retrograde path near the Pleiades, is at the stationary point on the 21st, after which his motion is direct or easterly. The equatorial diameter of the planet on the 14th is 45"-o, whilst the polar diameter is 2"-9 smaller. The planet is very favourably situated for observation, and even in very small telescopes his belt-like markings and attendant moons form an interesting object. The following table gives the satellite phenomena visible in this country before midnight : — Q 1 1 1 1 P.M.'s. C Si P.M.'s H. M. Q 1 c c P.M.'s H. M. Jan. Jan. Jan. I I. Tr. I. 9 41 10 1. Sh. I. 7 0 21 III. Sh. I. 7 19 II. Tr. I. 9 4C I. Tr. E. 8 10 III. Sh. E. 9 19 I Sh. I. 10 36 III. Oc. D. 8 57 24 Tr. I. 9 37 II. Sh. I. II 36 1. Sh. E. 9 13 Sh. I. 10 51 I. Tr. E. II 53 III. Oc. R. 10 46 II. Oc. D. II 31 2 I. Oc. D. 6 57 II. Ec. R. II 18 Tr. E. II 50 I. Ec. R. 10 3 II I. Ec. R. 6 27 25 Oc. D. e 54 f I. Sh. I. 5 5 12 11. Sh. E. 6 II Ec. R. 10 19 III. Oc. D. 5 25 14 III. Sh. E. 5 17 26 Tr. E. 6 18 I. Tr. E. 6 20 16 I. Oc. D. •0 35 II. Tr. I. 6 20 III. Oc. R. 7 10 17 I. Tr. I. 7 46 Sh. E. 7 33 I. Sh. K. 7 IS I. Sh. I. 8 55 II. Sh. I. 8 51 II. Ix. R. S 43 11. Oc. D. 9 4 11. Tr. E. 8 56 III. Kc. D. 9 16 1. Tr. E. 9 59 11. Sh. E. II 28 III. Ec. K. 10 59 I. Sh. E. 11 8 28 II. Ec. R. 5 48 8 I. Tr. I. II 30 IS 1. Ec. R. 8 23 III. Tr. I. 6 17 0 I. Oc. D. 8 45 19 1. Sh. E. 5 37 111. Tr. E. 8 14 I. Ec. R. II 59 II. Sh. I 6 12 III. Sh. I. II 20 10 I. Tr. I. 5 57 II. Tr. E. 6 2-; 31 Tr. I. II 29 II. Oc. D. 6 40 1 II. Sh. E. 8 50 ' Oc. U." denotes the disappearance of the Satellite behind the disc, and " Oc. R." its re-appearance ; "Tr. I." the ingress of a transit across the disc, and "Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across the disc, and " Sh. E." i's egress. Saturn (Jan. i, R. A. 22'' 8""; Dec. S. 13° 9'. Jan. 31, R. A. 22'' 20'"; Dec. S. 12° o') is now getting to the west and will soon be out of range ; near the middle the month the planet sets about 7.30 p.m. The northern surface of the ring is presented to us and we are looking upon it at angle of 9°. Uranus (Jan. i, R. A. i8h 2i">; Dec. S. 23° 37™) appears in close proximity to the Sun and is therefore unobservable. Neptune (Jan. 17, R. A. 6'' 37""; Dec. N. 22° 13') is due south about 11 p.m. near the middle of the month. The planet is situated in Gemini, some 6' east of the star fi Geminorum, but in small telscopes it is difficult to identify among the numerous stars in the same field of view, but he can be detected by his slight motion if observations are made on several successive nights. Meteor Showers : — i Radiant. R.A. Dec. Name. Jan. 2-3 17 h. m. ' XV. 20 1 XIX. 40 + 53'' + 53° Quadantrids. 6 Cyganids. Minima of Algol may be observed on the 15th at n.4 p.m., the i8th at 7.53 p.m., and the 21st at 4.42 p.m. 0 Ceti (Mira) should be watched, as it will probably reach a maximum during the month. Telescopic Objects : — Nebula. — Orion Nebula, situated in the sword of Orion, and surrounding the multiple star e, is the finest of all nebulae ; with a 3 or 4 inch telescope, it is best observed when low powers are employed. Crab Nebula (M i), in Taurus, situated about i|° northwest of s' Tauri in R.A. 5^ 29"", Dec. 21° 58' N. Clusters. — M 37, situated in Auriga, is one of the finest clusters, and very compact, its position is R.A. 5''. 46™., Dec. 32° 32' N. Double Stars. — jS Orionis (Rigel), mags, i and g, separation g". On account of the brightness of the prin cipal star, this double is a fair test for a good object-glass of about 3-inch aperture. 0 Orionis, mags. 2 and 7, separation, 53" ; easy double. (- Orionis, triple, mags. 3, 6, and 10, separation i^'- and 56"; rather difficult in a 3-inch telescope. X Orionis, mags. 4 and b, separation 4"-5 ; pretty double. 17 Orionis, triple, mags. 4, 8, and 7, separation i2"-5 and 42' . January, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 339 SUPPLEMENT. London's TraLnsformatiorv. A Svjggestive Sketch of Da.ys to Come. [Continued from page 314.) By Tems Dyvirta. [Cornelius Tush was agreat Ameri'-an financier, whose modes of business were perhaps not always quite above suspicion. He had hit upon the great idea of diverting the course of the Thames so as to cause the river to flow away to the country, and leave its dry bed in London available for building sites. He had made business arrangements with a number of people, had formed a large Company to malie the deviation, and finally the work was completed. Tush, however, was sorely disappointed with the treatment he had received in England, where many people looked askance at his methods, and had returned to America.] CHAPTER VIII. LiBERTiA Street. A period of peaceful repose having healed the sore- nes.s of his heart, Tush had returned to England to view the outcome of his ambitious scheme. For the third time he stood on Westminster Bridge and leant upon the parapet to gaze on the scene below. .'\nd well might he ponder, for what a different sight now presented itself to his eyes to that on which he had looked so long ago, when nothing but a sea of turbid waters flowed beneath, and later, when the busy hum of machinery resounded over the irregular masses of heaped-up earth and woodwork. What he now looked down upon was an extensive view of the finest street in all the world. A thoroughfare worthy of the great city of London. " Libertia Street " (" Avenue " was originally suggested, but the old English " street " finally adopted) is over 200 feet wide. On either hand rise magnificent new buildings of imposing architec- ture. The sound of the hammer and of the trowel still resounds in the air, telling of the new structures arising among the scaffoldings between. Here, on the right, is the huge " Hotel Thames," with its tiers of balconies rising high above the bridge. There to the left, with its gilded statuettes, is the Royal Thames Theatre. Next that of the prettily turreted building of the new Radical Club, while opposite is the great block contain- ing the " World's Emporium," and further on is the great National Opera House. Awav in the distance are the towers of the new Palace of Justice. Besides the many h.mdsome detached edifices are the rows of shops and business houses. Their ground floors abut on the street, and contain for the most part the parcels oflices and packing store.s, readily axailable to the carts in the street, while, in many cases, vehicles can drive in through porticos to inner court yards. On the roofs of these lower stories runs a wide pavement for pedestrians, .^t intervals are inclines or steps leading to the roadway below, and foot-bridges span the side streets. Glass verandahs jut out over the shop fronts, giving shelter from the rain, while not darkening the display of tempting goods in their windows. Above thein the gre:it buildings rise to six or eight stories high, even looking down from their parapets on their poor old kindred of the high-level town around them. Every building is of artistic design, and all now look so bright and clean in their newness, that a very pleasant effect is presented to the eve. Down the centre of this great thoroughfare runs an avenue of fresh green trees, bordering a gravel walk, whereon are seats and chairs, shelters from the sun and rain, drinking fountains, newspaper Kiosks, coffee stalls, and retiring rooms; all beautifully and tastily arranged, at hand, yet not interfering with the traffic. Even monuments are in course of erection in suitable spots; these are not ugly bronze figures of men in everyday attire standing on solid blocks of stone, with blackened faces, unrecognisable as representatives of their originals. Such statues are no more picturesque than the passers-by themselves; but here arc artistically- grouped statuettes on ornamental pedestals. On either side of the central avenue are cab-stands and space for waiting vehicles, and tram lines run along outside. Then comes the enclosed road reserved for the out-of-date horse-drawn traffic, which, of course, is prohibited from sullving and wearing out the clean asphalt, on which the horses would, moreover, be slipping down and running away. Outside this are the broad, open, asphalted roads, now teaming with traffic overflowing from the much congested thoroughfares of the old city, and forming a splendid unimpeded route from East to West of London. For this ereat highwav extends along the course of the old river as far as the new Docks at London Bridge. There a fine wide wharf runs across the river, forming a fitting point of departure for the smaller passenger boats leaving the port of London. W^hat a pleasant change from the dirty old crowded wharves of olden davs ! Anv dav one may .see ten or a dozen steamers lying with their sterns towards the wide quays, embarking heir passengers as trains do at a large railway terminus, .Along the old embankment (the stone facings of which have now been inoved to line the sides of the Canal) are the shop fronts of the new houses whose lower floors abut the fine, though comparatively narrow- streets which run along parallel to the great Libertia Street. To the south of the main thoroughfare runs a second narrow street, and in this are some of the huge buildings affording comfortable accommodation for thousands of the working classes. All are built on the latest approved methods and with all the modern ap- pliances for living in health and comfort. Each family has its own suite of rooms, with balconies and window- gardens, and everything that a poor Londoner can expect. Many of their windows overlook the Canal, which important waterway connects the docks with the various citv warehouses and enables water traffic to be conducted from the lower to the upper Thames. It was a bright sunny day, for days are generally brighter now; no longer do such dense fogs hang about the valley of the old river. Fog is but the visible effect of aqueous vapour suspended in the air; without the exoanse of cold humid water and damp earth this could not exist. The ininute particles of smoke, which, dampened bv the vapour, form the p.-ill which used to hang over the city, are now dry and fall to the ground as dust, leaving the sunshine to warm the air and beautify the surroundings. \'et was Cornelius dull. " Uneasy lies the mind that grabs the gold ! " Troubles seem unending. .A journev to the ."^tates and a sojourn there of eighteen months should have appea.sed the public mind. Their new. plavthing should have caused Londoners to forget their pettv squabbles with the donor. Rut no ! he had come back to find himself an outcast, shunned by all. He had arranged to see his solicitor that day and to discuss with him the unsatisfactory aspect of affairs. But first he would have a look around the new city of his creation. Descending by some steps, ho pur- sued his wav along the great broad walk beneath the bridge. What a grand sight now met his gaze ! For 34° KNOWLEDGE & SCIENTIFIC NEWS. [January, igo6. a magnificent open space lay to his right, laid out with flower beds and grass plots, and beyond a truly noble flight of steps, broken with balustrades and statues, forming the grand approach to the historic terrace from which rose that noble pile, looking so much grander when seen from below, of the Palace of Westminster. For some time he stood wrapped in admiration. Me felt that the British House of Representatives now really equalled that of the States; for how would the Capitol at Washington appear, from an architectural point of view, were it situated in a depression, and looked down upon instead of being looked up to? Further on, great houses with their shop fronts again walled in the streets. To the left was a bridge spanning the Canal, now packed with barges being towed up and down to the various wharves lining its sides. All was changed and altered ! Like the inhabitants themselves ! The very buildings in their grandeur seemed to cut the millionaire dead ! Calling up a motor car he jumped in and was whisked off to interview his lawyer and hear how things were de- veloping. Rapidly he was sped along the smooth asphalt down the great thoroughfare. Onward he went under Westminster Bridge, past the great North- umberland Avenue approach whence a glimpse of Trafalgar Square could be obtained, till, passing up on to the Embankment near Waterloo Bridge, he was deposited before the great buildings of the Xew Temple facing the Inner Temple Gardens. Here were situated /lumbers of new chambers for barristers and solicitors, who, in their increased numbers had flooded out the older rookeries of legal experts. Entering the offices, he there found assembled some half-dozen men, his associates in business and others. The grey-haired solicitor eyed him gravely as he entered, and spoke earnestly in a hushed undertone. Serious, indeed, was the import of his words. The interview did not last long. Tush, for a wonder, was ver-- taciturn, and said but little in reply to the anxious exhortations of the lawyer. Presently he turned and caught sight of Bateson, who was standing whispering mysteriously to one of the others with his eves fixed on Cornelius. " You have brought all this on me," roared Tush, livid with rage. " You scoundrel ! " Then, turning to the others, he recognised some of the prominent shareholders in the great company, some who had been addicted to asking awkward questions. " That I," he muttered through his teeth, " I, who could buy up this whole blessed city, that I should re- ceive such insult I Such ignominy ! You dare to threaten me, do you ? Call me ' swindler ' and have me up in your dirty Law Courts for fraud ! Xo, no, my friends. You'll find f/iat won't pay. W'hy, I could put you down a million apiece to keep your tongues from wagging, aye, and not feel it. Only I wnn't. I'll have nothing more to do with you darned Britishers. I've got all the dollars I want out of you, and now I can face my own countrymen, thank God ! Onlv I should like to spoil all that fine street I've made for vou first. Thankless curs I " And turning on his heel he left the room. CHAPTER IX. The New Thames. Happy is the man who amidst life's storms has ever at hand a harbour of safetv wherein he can obtain rest and peace; a home of refuge for his troubled mind, a comforter and friend, in whom he can confide, and luckv was Cornelius in having such a possession still to fall back upon. Returning to his rooms in the palatial Thames Hotel he found his faithful Alma and his petted and affec- tionate daughter. What soothing influence they brought upon his agitated brain! "Alma," he said calmly, " we must leave this cursed country. Never again shall I put foot in it. We will return to our own old States, and there we may find peace and happiness, but not here; we must be off by the first bo;it.' His tactful wife soon grasped the situation. She saw how greatly her husband was worried over his business, and she, too, knew how dangerous that was for him whom the doctors had declared possessed of a weak heart. She soothed him gentlv, but still she divined the serious causes that influenced his intentions. "Cornelius," she replied, " you are worried and upset. We cannot start to-day. Let us, then,. go for one more delightful quiet sail on the lovely river. It will do \ou good, you know it always does." So leaving their rooms the trio went forth, bent on enjoying the last few hours thev might have in England. How little did they think that for one of them it was the last few hours in any land ! Within a short space of time they were rattling along in the train through the southern districts of London, when, on passing clear of a large factory, a brilliant scene was presented to their eyes. A peaceful, pleasurable sight, yet one to sicken and embitter Cornelius' feelings ! Another of his creations to be presented to his enemies, for the train approached a long, a very long bridge, and this bridge spanned a broad stretch of water, the New Thames ! Looking down from this eminence a good view of the grand river was obtainable. Dotted about on this were numerous sailing boats and small yachts, beating their wav hither and thither, their white sails looking so clean and bright against the blue water and the green trees beyond, for there on either bank were the newly laid-out gardens of many little villas cropping up like mushrooms all around. This splendid artificial lake, here of great width, but further on narrowing into the gorge of the great cutting through the Surrev Hills, formed, indeed, the much-needed playground for boat- loving Londoners. How much appreciated it was by the old hands who had steered their craft on the narrow and enclosed reaches of the old Thames ! And what lovely little surburban retreats there were springing up upon its rising banks ! In a few years more, when those voung saplings had attained mature dimensions, would not those wooded slopes compare even with the picturesque confines of the Bosphorus? Soon the party had alighted at the little station now crowded with people clad in white flannels and straw hats, for it transpired that a regatta was being held. Thence thev walked down to the river-side and on to the landing stage of " Tvler's," and soon were seated in the smart little centre-board vacht, the Wafer Witcli. This vessel had been bought by Cornelius but a few davs previously as a means of escape from that society which he now so disliked. But a few minutes more and the little ship was sailing off gailv before the strong gusts of wind which rippled over the deep blue water, breaking up the monotony of colour from the ice-like calm under the windward banks. No feeling is pleasanter, no motion more calming to the mind, than that of gliding in a sailing boat through the water in a fresh breeze, with the gurgling sound of the tinv waves rippling against the sides of the vessel. Cornelius, ever determined to have the supreme com- mand in all things, took the helm and piloted the yacht on its voyage. First thev sailed over to where the regatta was being held. The course, clearly marked out with buoys, almost as distinctly as a race course January, 1906 j KNOWLEDGE & SCIENTIFIC NEWS. 341 iishore, had to be crossed at one of the points arranged for the purpose at stated intervals. " Heaving to " for a time, the party were able to watch one of the races, which were well seen, too, for the whole length of the course by the hundreds of spectators comfort- ably seated about on the slopes of the rising river bank. How preferable to the crowded towing paths of the old Thames on such occasions ! This wide portion of the river had been so con- structed in conformity with one of the stipulations of the Government, influenced bv a deputation from the combined sailing and rowing clubs. Lower down the rising hills involved large and expensive cuttings, and there, consequently, the river was narrower. Having taken a turn among the mass of boats full of onlookers, and past some of the launches lying av\ay while their occupants consumed their champagne and ices, the little family party decided on taking a trip further down the river; further from the " madding crowd." The Water Witch soon sailed in under the lee of the great cutting and was almost becalmed, drifting slowly along with the current. Steering now being un- necessary, if not impossible, Cornelius left the tiller, and making fast the main sheet to prevent the boom swinging over, reclined at his ease close to w-here his wife and daughter were sitting. This was truly bliss ! What need to quarrel with one's fellow creatures when one's time could be spent drifting thus leisurely in the quiet summer evening so far from all worries and troubles, and even able to avoid the inquisitive and sometimes scornful gaze of passers-by. Everj'thing seemed peaceful and still. Other boats were being sailed and rowed about, but none were near enough to disturb the repose of the occupants of the yacht. All of a sudden the wind freshened. They had drifted on beyond the bluff to where a valley ran down towards the river. Before the party realised their position a strong squall caught the sail now tightly fixed by the main sheet. The boat gently heeled over more and more. Cornelius sprang to the helm, but in his hurry tripped and fell sprawling to the lee side. This extra weigh! suddenly thrown on the beam was the finishing touch, the gunwale sank under the water, the vessel r.ipidly filled, and turned on its side, the mast and sail sinking under. All the occupants were thrown into the river. Libertia, an expert swimmer, had seized her fath'i'r as she saw him rolling into the water, and now held him with one hand, as she clung to the half- submerged boat with the other. In vain thev struggled to right it. Cornelius was no swimmer and could assist but little, and for some moments w-as so involved in gasping for breath and getting a firmer hold of the boat that he did not notice the absence of his wife. " Alma," he gasped, " Alma, are you safe? " But no response came. No response beyond the agonizing cry of Libertia, who plunged under water in the vain hope of seeing her mother. But nc\cr again was that fair form seen alive. Held down beneath the sail her last breath must have been soon drawn, and ere the witnesses of the disaster, who hurried their boats to the spot, had rescued the immersed couple, her bodv must ha\e sunk beneath the depths of water which, but for her husband, would, perhaps, never ha\e covered that spot. Poor .Mma ! That sweet accom- plished, faithful v\ ife and mother, whose life had alwavs iDeen such as any woman might envy; upright, seif- sacrilicing, and true, was gone forever. Manv hours had passed before the bodv with its beautiful white face, calm and serene, was dragged from the river and laid on the bank while endeavours ■were vainly made to restore animation. A few days more and all that was left of his beloved wife had been laid in their last resting place, not far from the banks of that treacherous stream, and Cornelius took his heart-broken daughter back to their own mother-country, bidding farewell, as he said, for ever, to this land of spite and thanklessness. CHAPTER X. Setti.ng the Thames on Fire. It was in the early hours of the morning on the day following Tush's departure for America, when all the tow n w as hushed in silence, or as near approaching that state as it ever is, one of the watchmen at the " World's Emporium " was going his rounds when he detected a smell of burning, and passing through the building to the department whence he thought it emanated, found the place full of smoke. He then suddenly noticed one of his mates lying on the floor apparently insensible. .\s a matter of fact, he felt somewhat suspicious at the time as he did not consider the smoke so thick at that spot as to cause asphyxiation, and he very easily aroused the watchman to consciousness. It was then discovered that a very extensive fire was raging, also that the " automatic sprinklers," which should have at once sent a deluge of water on the spot, had ceased to act, as though the water had been turned off. The alarm was quickly given, and in a very short space of time the fire brigade was busily at work subduing the flames. One after another motor fire engines came dashing along the empty streets, and drew up before the burning building. Hoses were soon got out and attached to the hydrants, and before long tons of w ater were being poured on the flames. But whilst this was going on, a policeman on duty bv the Canal near Southwark, noticed smoke issuing from a large new warehouse, and soon a second great conflagration was in progress. Urgent calls were issued to outlying stations, and the fire brigade had its hands full. .A third fire was then reported down near the new Docks, and hardly had this been taken in hand than it was found that the upper floors of the Thames Hotel were ablaze. .AH this was a tremendous strain on the brigade, and it would have become a very seri- ous matter, indeed, had it not been for two facts. Firstly all the houses had been constructed in conformity with stringent rules issued by the London County Council regarding various details for the prevention of fire. .Such would have been impossil)Ie to apply to existing buildings, but these had been introduced alter receiving the most careful attention when first it had become certain that a large number of new- buildings were to be erected. It was then decided that this would be a great opportunity for intrt)ducing new regulations with regard to the construction of all edi- fices. .All were to be fitted with automatic alarms (though in each of the present cases these had, for some unaccountable reason, failed to act). .Among other de- tails all were furnished with hydrants and stand pipes to suppv a copious amount of water under considerable pressure, \arious means of escape, too, had to be provided, and fire-proof materials entered into the con- struction and fittings. The second reason for the comparative ease of being able to subdue the flames was the ample water suppiv flowing from these hydrants. Great mains had been laid in the old river bed whence an inexhaustible volume of water came direct from the Thames. This arr.ingement proved to be of the greatest use for fire extinction, as a mass of water, almost to be com- parable to a river itself, could be poured on the flames. The fire raging at the hotel presented a most exciting 342 KNOWLEDGE & SCIENTIFIC NEWS. [Janlary, iy<.6. spectacle to the great crowd which soon assembled. 'J'he guests dashing to the windows of their rooms were seen to cast out some simple folding ladders (in con- formity with the printed directions in all the rooms), and by this means were enabled to reach the balconies below, whence, by the iron staircase, they could descend to the main balcony above the street. Hundreds of them in all \ariety of attire were stream- ing down the front of the building, looking for all the world like so many white ants whose nest has been disturbed. Owing to these excellent arrangements there was no loss of life in the enormous buildmg. Firemen, and even policemen and soldiers were, on the other hand, scaling the building with their ladders to direct thin jets of water in at the windows from the hose attached to the iron pipes, which conxe) cd a copious supply of water to the tops of the houses. The great, wide street, and the bridges that spanned it, formed advantageoits coigns of vantage for the many thousands who had come to watch the sensational operations. \'ery soon, however, thanks to the timely measures which had been adopted, each of the fires was extinguished. Then, as all the spectators wended their several ways homeward, tongues got wagging, and e\eryone was enquiring- how so many fires originated at the same time all in this one new district. Later on other facts came to light. Eventually it transpired that some large insurance operations had been effected in the name of Tush. Then did some recall certain words used by that gentleman in the solicitor's office just prior to his leaving the country. Many of those returning to their homes or going to their day's business made their wav eastwards through the great markets under London Bridge. Now that old Covent Garden had been transformed and built over this was the centre whence Londoners obtained so much of their food supplies. Magnificent conserva- tory-like buildings rose on all sides, and the well-Da\ed floor was kept scrupulously clean by lavish drenches of water. Among the stream of those passing through, one man was noticeable, for in him we may recognise the agent, Bateson. Continuing his way into the purlieus of Bermondsey he might have been seen to visit certain low haunts, become engaged conversing and discussing matters with several well-known disreputable charac- ters, and effecting certain monetary transactions with them. 'J'his done, he threaded his way back to the city. Later on Mr. Bateson might have been seen entering the colossal portals of the " Tush Buildings," situated just beyond Blackfriars Bridge. Ascending rapidly in the hydraulic lift, he was landed on the nth floor, where were the offices of the Griffin Insurance Society. His business was, he explained, to claim on behalf of I\fr. Tush, immediate payment with re- spect to insurance policies issued in his name on cer- tain buildings situated in Libertia Street and that neighbourhood, which had been damaged by fire on the previous night. He explained that the reason of his somewhat sudden demand was because of Mr. Tush's departure for America. " But," retorted the manager, " this is just a matter on which I was requiring some information. I happened to meet Mr. Tush some days ago, and knowing that he had lately insured a number of buildings in very large amounts, I alluded to the matter, when, to my surprise, he denied having effected any insurances whate\er." "Ah, you see," replied the agent, " Mr. Tush is a peculiar man. His hands are so full of business that he frequentlv forgets what little affairs he has transacted. \o\\ ' I manage all these things for him .■uid keep count of thrm, .ind 1 hold his power of attorney for transacting such busi- ness." Nevertheless, the manager was not at all satisfied, and as rumours had reached him with refer- ence to suspicions as to the origin of the fire, he politely declined to redeem the policies pending further enquiries. Bateson was evidently somewhat discon- certed about this and left the office abruptly. It was a hot, stifling dav. In some of the older quarters of the town life seemed almost unbearable. \\'arm blasts of wind sent clouds of dust to thit^ken the air and fill the eves and lungs of passers-by. The glaring ravs of sun, almost tropica] in its intensity, beat down upon the dry-mouthed, sweating wayfarers. Dust penetrated everywhere, and whence this dust? The disintegration of the road materia! by the continu- ous hammering of iron hoofs and crunching of iron- bound wheels, the refuse strewn over the streets by the horses, and the gravel scattered upon them to pre\ent the slipping during damp and frosty weather. But the new districts in the river-bed were better off. Foot passengers strolled beneath the green trees or shady verandah?, while the clean asphalt, unworn by the soft rubber tyres of the motors, emitted no dust, and the plentiful water supply enabled the roadways to be pro- fusely sprinkled from the many stand-pipes. Bateson wandered about uneasily trying to rest under the soothing influence of the shadv trees in the centre of the street. He was cogitating on his future actions. Finally be decided, being somewhat apprehensive of what the future might bring, on getting together, while there was yet time, as much personal property as he could collect. With this object he walked off to the Bank of England. This national storehouse of wealth, emblematic of the mightv iMiipire, had long since out- grown the old buildings in Threadneedle .Street, and was now contained in that splendid block extending from Cannon -Street on the north and continuing south to its noble facade in Libertia Street, thus connecting the old city with the new. Business in London was now double what it was twenty years ago, and the Bank of lingland is but an index of its magnitude. As with many other institutions, it is difficult to compre- hend how they could have been sufficiently enlarged to cope with the growth of tr;ide and increase of wealth, had it not been for the utilisation of the Thames. Passing through the grand entrance hall, Bateson hurried nervously along and visited one department after another (and the interior of this office may be compared to a small city in itself), endea\-ouring to effect the somewhat complicated business he had in hand. In due course it was all satisfactorily arranged, and he quitted the building to visit another of those great piles of offices towering into the sky, numbers of which had been erected in this neighbourhood, adding immenselv to the much-needed business accommoda- tion of the city. Here he asked for an interview with the manager of another large fire insurance company. This time Mr. Bateson was still less fortunate than before, for certain inquiries had in the meantime been made and certain transactions come to light. The result was, that after being detained for a very considerable time in the waiting-room, the manager entered accompanied bv another man, and after a few- words of explanation, introduced the latter as an official from Scotland Yard, who would conduct Mr. Bateson to a certain place where further investigation was now being made as to the origin of last night's confliigrations. And it may here be added the result of these investigations were so unfavourable to that gentleman that for a long time afterwards he was not seen in public. {To be concluded.) 343 KDooiledge & Seleotifle Hems A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. 15. [new series.] FEBRUARY, 1906. SIXPENCE NET. CONTENTS- See page VII. TKe ColoroLtion of MaLminaLls ©Liid Birds. By J. Lewis Bo.nhote, M.A., F.L.S., F.Z.S., M.B.O.U., etc. (Cimtinucd from page 317.) Let us now consider for a moment the question of those mammals whose pelage changes at certain seasons of the year. Roughly speaking, in the tropics, the wet and dry seasons correspond to- our summer and winter, so that, if an animal is to be at all affected by the climate, the affection will show itself, roughly speaking, in spring and autumn, at the same time, approximately, as when the cold or heat are affecting the animals of more northern climes. Mr. Lydekker, in an article in the Field,* points out that Scinriis caniceps was the only tropical mammal that, to his knowledge, had a seasonal change. This particular squirrel, in company with another, .S. airpdorsalis, assumes in mid-winter a very bright or intense coloration on the back, which, as I have pointed out| some years ago, is caused by the advent of sexual activity, and not by any climatic or seasonal change. The climate at that time of year (December to February) is very constant, and this is, therefore, a clear instance of a change being brought about solely by sexual activity. On the other hand, we have certain species, such as Sciurus maclellandi, Ftinambulus berdnwrei, etc., in which their season of most intense colouring coincides with the summer or wet period, but in this case the change is merely one of relative brightness and not sO' marked as in the other cases. Among birds, the changes seem to be almo.st always " breeding changes " for they take place at the breed- ing season and are probably due almost entirely to sexual causes and impulses, and we would suggest that any changes in the tropics which may take place, as being purely due to seasonal causes, are to be found among the representatives of northern races where the necessity of a change arose and has not yet been eradi- cated. A good example is to be found in ]\/usicla flavigida. This animal, which is of a light brown and yellowish colour in Siberia, has in Nepal a marked seasonal change, becoming much darker in summer. In the Malay Peninsula, although both pelages are darker than those assumed in the North, the seasonal change still persists, while in Java and .Sumatra, the dark brown form is permanent throughout the year. In the Peninsula of India is also found another species {M. gwaikinsi), which is uniformly dark, and has, as far as we know, no seasonal change. • Field, 1903, p. 675. t P.ZS., igor, p. Toi sum up concisely : — Conditions of climate being more equable, " changes of pelage " are not so frequent in the tropics as in more northern climes ; when they do occur, they are probably due — (i.) Either to the sexual impulses alone, e.g., S. caniceps and S. airodorsalis. (2.) Or to a long ingrained habit,* owing to the animal having originally come from some climate where seasonal change was necessary, e.(i., Mustela flavigula, Cervusy and possibly Sciurus. TFMPER.A.TE REGIONS. After all that has been said on the other regions, there is not much to- note here, except to point out that the arguments for the other regions still hold good. In the first place it is fairly self-evident that in most of the mammals and birds of this reg-ion the prevailing coloration is brown; white mammals are as .scarce as they are in the tropics, and bright coloured forms be- long, without exception, to tropical or cosmopolitan families. The squirrel and the fox are good instances of mammals that have partially retained their bright colour, the former during summer only, the latter throughout the year; the deer also are red in summer. The birds also call for little comment on these lines. The bright species, as the kingfisher and roller, being typical of the tropics, and the SylviidEB, or warblers, typically birds of the temperate region, are brown. The chief interest of the temperate region, however, lies in those families that, stretching from the north and even penetrating the Arctic circle, mav also be found on the northern edge of the tropics, becoming brighter and brighter gradually and throughout the whole distance as they approach the southern limit of their range. More heat, better and more abundant food, more time between the periodic breeding season and the cold of winter, or the gentle advent of sprintr. all these are causes which, as we have shown, may and do affect the '" vigour " of the indi\idual, and it is bv means of that " vigour " and not by their direct action that we suggest the brighter colours are produced. • It is not advisable to press matters too minutely in a general paper, but it is perhaps worthy of note that in Conns clJi. an inhabitant of Burma, Malay Peninsula and Cochin China, the brightest pelage is that assumed and worn in winter, and is tlierefore hardly analogous to the ch.inges in C. ileawiceli, whose brightest phase is in summer, I would therefore suggest that the change in C. cldi is purely a breeding change and that it has progressed a stage further than C. axis and C. iwicolor, that have ,1 s'milar pe'age throughout the ye.ir, in having tirst eliminated the seasonal change and then adopted the breeding change ; this would merely depend on the balance between the sexual and climatic impulses. t For a further instance of the seasonal change pesisting under altered conditions, see Captain Barrett-Ham'lton. P.Z.S., i8og — P- 59^- (7o he continued.) 344 KNOWLEDGE & SCIENTIFIC NEWS. [February, 1906. The Evolvition of the Flower. By S. Leonard Bastin. (Continued from page 324.) PART II. The conspicuous and often attractively coloured sepals and petals of the flower, whilst servinor their special purpose, are, after all, of but small importance when they may be all joined together. Each carpel terminates in a longish pillar called a style, at the summit of which is the stigma, a moist, fleshy surface to which the grains of pollen readily adhere, .^t the base of the carpel is to be found the ovule, that highly specialised organ which is the forerunner of the seed. At first sight it is not an easy matter to determine what may be the origin of the highly complicated male and female organs of the plant. Both the sepals and the petals of a flower exhibit more or less resemblance to the foliage of the plant, but there is certainly not much obvious connection between stamens and [)istil In the Begonia, the rear relation between stamens and petals is clearly observable. compared with the organs which fill up the centre of the typical blossom. These, as is well known, are divided into two distinct kinds — the stamens and the carpels — the latter collectively forming the pistil. The former organs produce the pollen grains which, coming into contact with the latter, fertilise the ovules and thus bring about the production of living seed. As a rule the stamens are in the form of small processes having slender stalks surmounted by heads or anthers; it is on the anthers that pollen is produced. The pistil, as has been stated, is composed of a number of carpels, and these are sometimes verv distinct, or, on the other hand, and the leaf. Nevertheless, after the consideration of the instances which it has been the purpose of the pre- sent paper to bring together, it will be easy to credit the statement that the leaf \\as the ancestor of even the reproductive organs themselves. In the case of the so-called " double " flowers it will be readily seen that a very large number of extra petals have entered into the composition of the blossom. These additional petals must have had their origin in something, and, as a matter of fact, they are degenerate stamens. The manner in which this transformation of stamens i.-to petals is carried on is readily seen in the February, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 345 case of the Begonia. The florist has hitherto been com- pletely vanquished in his attempts to produce a variety of Begonia which shall throw nothing but double flowers on each spray — a single flower alw ays putting in an appearance. Occasionally a blossom is to be found in a curious midway state between the single and double condition, and when this is the case an interest- ing side light as to the connection between stamens and petals is to be seen. It is possible to trace the gradual degeneration of the stamens into the petals; some of these eccentric organs are just simply flattened stamens, resembling miniature petals except for the fact that they are covered with a deposit of pollen. Others have got away from the pollen altogether, ha\c developed the coloured tissue, and are perfect petals in their way except that they are very small. Probably one of the most marvellous object lessons in the whole of the plant world bearing on the origin of the stamens is to be seen in the case of the flowers of the Water Lily (Nymphcea alba). By a careful dis- section of the flower of this plant a most instructive bring forward further proof in support of the assertion that there is a very intimate connection between the stamens and the petals of the flower. As has been clearly shown on a previous occasion, the petals of the ngle Cherry bloom (left) compared ke carpel of double Cherry flower. bloom have been obviously developed from the stamens, and these latter bring us back to the all-important leaf. To trace in a clear fashion the leaf origin of the pistil is not quite such a simple matter as it was in the case lU • elation^ betv of the Water Lil series of organs may be compiled, in w hich all the stages l>etvveen the stamens and petals may be discerned. Starting away from the outride of the flower with the green sepal, it is interesting to note that this is partially coloured white, offering yet another proof of the origin of the petal. Passing over several rows of perfectly formed petals, it is noticeable that these are steadily de- creasing in size the nearer one gets to the centre. Gradually these petals become modified in form until they are quite narrow, and at last one is seen to be curiously thickened at the point. This point is yellow in coJour, and a microscopic examination of the sub- stance re\cals the fact that it is pollen. 'I"he termina- tion of this organ, which one can call neither stamen nor petal, as one advances inwards, continues to be more and more modified until it rcsohes itself into two thickened parts; eventually these meet together and form the two lobes of the anther. Moreover, at this stage the petal-like process disappears altogether, narrowing down until it forms the filament of the stamen. In the inside rows of the stamens it is not possible to discern any resemblance between the petal and the male rcproducti\o organs. A similar process to tli.it which is so striking in the crLse of the Water Lily flower is to be .seen in the blossom of the Pa-ony, and, as well, other instances might be noticed. But it will scarcely be necessary to of the other three organs of the bloom which have already been dealt with. As is well known, the pistil is A Double Cherry bluum \\iX\\ the exposing the .n, until its surface is beneath the le\el of the sea. Hut marine (Iciuulalioii, siniplv, ni;iy be the cau.se of many a noble cliff crumbling away. It is estimated that many of the prevalent storms which arise in the .\orth Sea show their effects on our eastern and north- east coast in waves which beat upon the cliffs with a force varying between two to three tons to the square foot. A change in the nature of the strata in a cliff, owing to the strata dipping at an angle in a direction parallel with the coast, will be sufficient for such a force to find a suitable lodgement on which to play with success. Or it may result in undermining, until the upper parts of a horizontally stratified cliff may project several feet beyond the base of the cliff. In that case a period will be soon reached at which the overhanging portion will fall. Then marine action, which commenced the process by its undermining action, will complete the work by bearing away the fallen material, and rcdepositing it elsewhere. But such redeposition seldom results in the formation of land elsewhere. It mav shoal up a sea, but only to a certain point. A\'ithout any subsequent submarine upheaval, the debris of the land so denuded rarely results in dry land. Without a counteracting uprise, the tendency of the land is towards complete disappearance beneath the sea. It is not alwavs realised that were the de- The Rai.sed Beach, showing Cave-like Holes (/>') where the Loose Larger Stones at the top have fallen away. nudalion of the land to gO' fonvard unchecked, the result would be the complete disappearance of our land areas. In fact, so great is the preponderance of sea-areas that were the earth completely spheroidal. there would be a universal ocean two miles deep. For- tunately, as geology teaches us, time after time the results Of the degradation of the land have been ren- dered nugaton,- by upheaval. But in our own country, at the present time, we have no decisive evidence that either upheaval or subsidence is going on. Denudation of our coasts proceeds with no check placed upon it by natural cau.ses. It will be- come a serious question as to whether artificial pro- tection will not sooner or later become an imperative n.itional concern. The last movement of upheaval which Ivngland under- \\cnt was that which on our south coasts elevated the raised beaches which .are there found, and even though the existence of buried forests seems to show a sub- 350 KNOWLEDGE & SCIENTIFIC NEWS. [February, 1906. sequent partial downward movement, this was not suffi- cient to counteract the former upward movement. The result is seen in the raised beaches and rubble-drift formations which have from time to time been described. The Briijhton cliff formation is one of the best examples ol this kind. The formation occurs at the east end of the town, and owiny to its nature is liable to constant f;dls. Thus fresh sections are frequently being- exposed. At the present time, the lower portion of the cliff consists of about ten feet of chalk. Upon this chalk rests about eight feet of beach. This beach was sorted in the same w-ay that modern beaches are sorted now, so that we find upon the chal'.; a g-ood deal of sand and small pebbles, and these in- crease in size upwards, until large flint boulders com- plete the higher portions of the beach. Although the beach is mostly of flints, it also contains a few rolled granite boulders and rounded lumps of red sandstone. Owing- to lack of cementing material in the beach, it is constantly falling on to the lower beach, and cave- like holes are formed. Then, in the course of time, the rubble above it, having lost its natural support, falls on to the beach below, and is rapidly carried away by the sea. The rubble forms the remainder of the cliff. This diagram shows that the Channel formerly extended further in a northernly direction than now. (.-1) Raised Beach. (Bi Rubble-drift. Brighton Beach. It is of a brown colour, and contains numerous rounded and sub-angular pebbles of chaJk and flint, varying very much in different parts. It was in this rubble-drift that Mantell found remains of Elephas primigenius, and hence the name of Elephant Bed sometimes applied to it locally. Rhnwceros tichoriniis, Cervits elaphas. and Hippopiiamus major were also found. The nature of the animal contents shows that the time ol its formation (Pleistocene), although geologi- cally of fairly recent date, was yet far removed, if one counts by years, from existing times. The upward and then the partial downward movements which have since occurred, have now completely come to a stand- still, but the denuding action of the sea continues, and this in so porous a material as the rubble-drift is aided by sub-aerial denudation. Where the coasts are formed entirely of chalk, erosion by the sea is not so marked, although it is far from being negligeable. But when we look at our eastern coasts, and consider the fragile nature of the material of which our cliffs are there formed, we almost wonder that coast erosion has not been more marked than it has been. The boulder- clay cliffs of south-eastern Yorkshire render that coast peculi:u-ly liable to denudation. The inlet of the Wash was brought about by the friable nature of the strata when once the chalk had been breached. The glacial and crag cliffs of Norfolk and Suffolk, and the London Clay cliffs of Essex all afford yielding material to the inroads of the sea. On the north of Kent, the London Clay is constantly slipping into the bed of the sea, together with other loosely-accumulated material of tertiars' age. When one looks at a map of our country, one cannot help being struck with the fact that it is not a little remarkable that the great bulge of the east c(ViSt is just in those parts where the coast-line is least protected. Our oldest and most indurated rocks are, on the n'hole, on our west coast.s. In general our strata dip from west to east, and this has been brought about by a tilting movement, which has exposed the edges of up- turned rocks of older date, as one proceeds westwards. ITie coming oi the North Sea may have been materially assisted by this movement, and since its advent, the sea has steadily continued to w-ork backward, until, in- \ Diagram showing the progress of coast erosion and the formation of cliffs on the East Anglian Coast: dip greatly exaggerated. Stead of breaking on a shelving strand, as it would have done at A, it has, by ceaseless erosion, produced the cliff at B. This is, in effect, the condition in which we find the cliffs in East Anglia. As a matter of fact, the \ ery existence of sea-cliffs is evidence of erosion, whether the cliffs be formed of igneous or sedimentary- materials; but to go back to the time w-hen that erosion commenced, one must go back to that time when the country last emerged from the sea. The task which engineers have now set themselves is to protect the sliores as they now are, and from a discussion which took place at a recent meeting of the Institute of Civil I'^ngineers, it seems to be generally accepted that defence works have, as a rule, been pushed too far sea-ward, as though to reclaim some of the land which the sea had already swallowed up years ago. The result has been disastrous to the unprotected areas in close proximity. To mention two instances only, -we find the scouring out of East Wear Bay largely owing to defence works at Folkestone Harbour, and the rapid succession of falls of the cliffs at East Brighton are directly owing to the scour of the tides after passing the town's defences. Tliere has been too much of the desire on the part of the local authorities of those areas which could afford defensive works to benefit at the expense of those owners whom it would not pay to make great outlays. It is well that engineers recognise this, since in their individual capacity they are responsi- ble for the erection of all such defence works. R.oma.n Coins at Hull. The Municipal Museum at Hull has recently acquired an extensive and valuable addition to its collection of local Roman, &c., remains. It consists of the life work of a somewhat eccentric character, Tom Smith, of South Ferriby, locally known as " Coin Tommy." The specimens are principally of Roman date, and include over 2,000 coins, nearly 100 fibulse of a great variety of patterns, several dozen buckles, pins, dress fasteners, ornaments, strap ends, bosses, spindle whorls, armlets, spoons, beads, objects of lead, &c. Amongst the fibulae are two of altogether exceptional interest, as they bear the maker's name upon them (.WCISS.V). Only two e.xamples of brooches marked in this way have previously been found in Britain (in Somerset), though they are recorded in France, Germany, Italy, &c. There is also an extensive collection of pottery, including many vases, strainers, dishes, &c., in grey ware, as well as many fine pieces of Samian ware. Febkuarv, igo6.J KNOWLEDGE & SCIENTIFIC NEWS. 351 PhotogrsLpKy Pure and Applied. By Chapman Jones, F.I.C, F.C.S., &c. Reversal and Re-Reversal. — It was about five and twenty years ago that M. Janssen observed, when photo- graphing the sun, that, with the particular sensitive plates he was using, an exposure of from one to two hundred thousand times the suitable exposure for an ordinary image gave on development a positive instead of a negative, and that by increasing the exposure to about a million times the image was again reversed, thbugh with a considerable diminution of contrast. These observations, expressed in the simplest form, indicate that a gradually increasing exposure followed by development, will give at first an increasing dark- ness of deposit, then a diminution of density, followed by another, though less marked, increase of density; and there seems to be some evidence that this alternating rise and fall of density resulting from a continually increasing exposure, might go on until the differences were too small for observation if interfering circum- stances did not step in to vitiate the experiments. It has further been suggested that the image utilised in ordinary negative making is not the first result of the action of light, but is preceded by a similar alternating action to that which seems to^ follow it. If this is so not only is the result of the continuous action of light of an alternating character, but the maxima first increase and then diminish, the effect passing, doubtless, itito changes of a different character. It is easy to prove the increase of density with in- crease of exposure as in ordinary negative making, and then a decrease as in the reversal resulting from over exposure, but to get further than this is, experimentally, so difficult that many have tried and failed, and not a few have, therefore, doubted Janssen 's original ob- servations, and believe only in one increase followed by one decrease in density. What appears to be a definite proof of a second increase of density has lately been supplied by M. Adrien Guebhard, who, in the Com pies Rendus (CXLI., 559), gives a reproduction of the result of one of his experiments. A Lumiere film was ex- [josed to daylight for forty-four days last August and .September, including only nine dull days, under a graduated screen made of white paper arranged in from one to twenty-two thicknes.ses, covered w'ith a cut-out black paper screen. The filrri was then developed for five minutes in an ordinary metoquinone developer. Confirnialorv results were also obtained on Eastman Kodoid films. The total exposure of forty-four days may seem excessive in dealing with a series of only twenty-two exposures, but the exposure durations ha\e to be in a geometric series. An initial exposureof approximately one second in a series of twentv-two, if each is double the preceding, would require about the time stated for the last. The impossibility of confining the light action to the part required is a very great dilliculty in such an experiment, because of reflection within the film. For anv who wish to test the matter for themselves, and reliable conlirmation of the .results obtained with an extension of them as far as possible would be very welcome to all interested in the study of pure photo- graphy, I would make the following' observations : — \ pure bromide emulsion (free from iodide) gives a nuirli more quickly reversible image than the ordinary mixture of bromide and iodide. One considerable dis- advantage in the use of commercial preparations is the uncertainty as to what they contain. Some plates now on the market are not simple emulsions of silver salts, and it seems at least probable that even the makers do not know what they contain, although, of course, they know what they use in their preparation. But still, experiments with commercial plates are interesting and may be useful. To avoid the interference of the long exposures with the comparatively short exposure effects, I would suggest getting the shorter exposure by means of a graduating device, such as what is commonly known as a .Spurge's sensitometer, and for the longer exposures using separate parts of the sensitive material each quite isolated from the other by being contained in a separate compartment of a multiple-cell box, or one of a number of small boxes. The exclusion of vitiated air, the avoidance of complications due to temperature changes, the results of comparative blank experiments to discover any interfering circumstances that may be present, the distinction in the result between printing- out and development effects, and other sucn matters must, of course, be taken into consideration. Shading the Lens. — The importance of so shading the lens, especially when working out of doors, that ex- traneous light is excluded from the camera, is not recognised now as it used to be, and never was generally recognised as it ought to be. If the glass of the lens were perfectly transparent, its surfaces per- fectly polished, the interior of tne mount of the camera perfectly non-reflecting, and the air perfectly free from motes, there would be, perhaps, no advantage in shading the lens ; but such conditions are impossible. The hood generally found on old lenses, but often not on new ones, is a little better than nothing. Years ago some photographers made large conical hoods, almost reminding one of small gramophone trumpets, and these were used even in studios with advantage; but this is not the kind of thing that will best serve the purpose. It is obvious that the shape of the opening at the outer end of a large hood or shade should corre- spond to the shape of the plate or that part of the plate that is to receive the desired image. If a light bellows could be attached to the camera front so that it could be opened out to extend a few inches in front of the lens, and carry at its outer extremity a screen with an adjustable rectangular opening in it, the shading of the lens would be ideal. This principle, but without the possibility of adjustment, may be easily carried out in those hand cameras in which the lens is within an outer case. The opening in the front of the case may be so made that w^hile the plate is fully illuminated, all the light that can be safely cut off is prevented from entering the camera. There is also advantage in using a camera made to carry a larger phite than that used and in fitting lenses into mounts of a larger diameter than is necessary just to hold them, ;ls in both cases the reflecting walls are further away from the path of the light being utilised, and the rellection is reduced. In spectroscopy and photo-micrography these matters are of considerable practical importance. The O plical L'rojeclion of Opaque Objects. — A piece of apparatus that deserves to be more widely known is the " Picture Postcard Lantern," made by Messrs. \\'. C. Hughes and Co., of Mortimer Road, Kingsland. It consists of a well-made and capacious Russian-iron lantern, within which arc two incandescent gas burners, one on each side, that illuminate the card held in a carrier at the back, and a lens in the front of the lantern that projects the image on to a small screen three or four feet away. While originally meant for 352 KNOWLEDGE & SCIENTIFIC NEWS. [February, 1906. picture postcards, it will gfivc an cnlarijed image of any papt-r print or diasjram, or of the page of a book without injuring the hook in anv wav. The image as given directly is, of course, laterally inverted, but where this is a drawback, as in the case of figures or letters, this is easily obviated by fixing a piece of silvered plate glass (thin patent plate silvered on the back serves well and is easily obtained in front of the lens and receiving the reflected image on the screen. In addi- tion to the ob\ious uses of such an apparatus, one can, by its means, judge at once from a small print whether an enlargement of it would be of advantage, and it will often save the trouble of making a lantern slide and arranging an optical lantern. TKe Glastonbviry Grace Cup. Peg-tank.\rds arc of the Saxon period. .\ fine speci- men of .^nglo-Saxon work, formerly belonging to the .\bbey of Glastonbury, is now in the possession of Lord Arundel, the noble owner of Wardour Castle. This old relic is known by the name of the "Glastonbury Cup, ' as tradition sajs it was carved out of a piece of the Holy Thorn on \\'eary-all Hill, when Joseph of Ari- mathea rested and planted his staff, which, like Aaron's rod, " budded and flowered." It is also known as the "Grace Cup," and the old belief still exists that it is Grace Cup in Wardour Castle. the original Glastonbury Cup which was used as a Grace Cup after meals in the refectory by the monks of the .Abbey. It is made of wood, and rests on crouch- ing lions, the bowl being carved w-ith the twelve Apostles. On the lid, the Crucifixion is carved, with the X'irgin Mary and St. John. Tlie Cup holds two quarts, and originally had eight pegs placed one above another inside, dividing the liquor into equal quan- tities of half a pint each. The Rule for the Infinity Focus. Bv ])R. (;. II. Hkva-W I'.k.S. Most instructions sent out with cameras contain some- what dogmatic statements as to the distance.s at which objects are in focus with a certain stop. It is sur- prising that so few people know the verv simple rule for such matters. Let a camera be focussed for " infinity," that is, for parallel rays (as in the cheaper box cameras), and let it be directed at a near object. Take two points on the object, w hose distance apart is equal to the diameter ot the stop. Then it is just possible to draw a couple of parallel rays from the two points to the lens, and these extreme rays will converge to the same point on the negative. If the points are further apart, no rays from one are parallel to rays from the other, nor do they consequently converge to the same point on the nega- tive. We thus have the following result : — In a fixed focus camera the impressions produced on the plate or film by two points of a near object will overlap if the distance between the points is less than the diameter of the stop. If the distance between the points is greater, the impressions on the plate will be distinct. In most cameras the stop is placed between the lenses. On looking through the front lens the stop appears slightly magnified, and a little simple reasoning shows that it is this magnified diameter, not the actual dia- meter of the stop, that must be taken. For instance, if, on looking into the lens, the stop appears to be half an inch in diameter, no objects less than half an inch apart will produce separate im- pressions; half an inch is, therefore, the limit of size of the details which can be shown in the photograph. It makes no difference whether the objects are near or far away. If they are near, details below half an inch in size may be large enough to appear blurred on tlie negative, if they are far oft', such details may be un- noticeable, but if the negative be enlarged to the same size as before they will present the same appearance as before, other circumstances being left out of account. -Another consequence of the rule may be noted. With a lens of four inches focus, the limit of detail will be one inch for stop f '4, and J inch for stop f/i6. With a lens of one inch focus the limit of detail would be \ inch for stop f/4, and i-i6th inch for stop f/i6. Suppose, then, that instead of taking quarter plate negatixes with a four-inch lens, we were to take nega- tives measuring about i inch by f inch with a lens of one inch focal length and a corresponding stop, and suppose we were to make enlargements of the same size from both negatives. Then the enlargement from the smaller negative would show four times the detail in focus at all distances; that is, details of I inch would be in as good focus in the enlargement of the smjiller negative as details of one inch in that of the larger. By c;u-rying a very tiny camera about in his watch pocket and trusting to enlarging, a photographer might be practically independent of focussing even for very near objects indeed, but for the fact that imperfections and coarseness of grain in the negatives would be enlarged correspondingly. February, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 353 The corresponding rule for a camera focussed for a finite distance is best shown with the aid of the acconi- panvint; figure. If A B represents the stop or its magnified image as seen in the front lens when focussed on a point P, at any given distance, details at any other distance will be separated in the photograph if iheir distance apart exceed the breadth of the cone A P B at that distance. I-' or instance, a h imd a' b' show the distances apart of points when the impressions they produce in the photograph just cease to be separate. I found these rules of great use during the recent visit to South .\frica, and the results obtained were in complete accordance with them, especially when other conditions were taken into account. CORRESPONDENCE. Green Flash at Sunset. I would call attention to a phenomenon of atmospheric refraction frequently observed, but of which very little has been published. I refer to the green flash seen in clear weather as the last ray of the setting sun disappears. I observed this one evening in the N. .Atlantic last month, and I also saw it in the N. Atlantic in Octoljer, lytjH ; on this last occasion I watched Venus setting a little later, but though the planet turned red occasionally as it approached the horizon, it did not flash green at the last moment. I have, however, seen stars set with a green flash, but rarely. The phenomenon is noticed in " Knowledge" for April, 1889, p. I2(), here the colour is given as blue ; in " Nature," March and .A.pril, 1S90, pp. 495, 538; and in K.A.S. notices, May, igoi. In these notices the writers appear to hold different views as to the cause. In Elementary Meteorology, by Professor W. M. Davis, p. 50, it is stated that after sunset every solar beam will be broken into a short vertical spectrum ; is this the e.xplana- tion ? If so, why should the last flash be green (according to some accounts, of a remarkably vivid green) ? I would like to see the matter worked out. J. P. Maclear. Chiddingfold, igth Dec, 1905. [Admiral Maclear's letter opens up the subject which has for « very long time formed a topic of discussion, especially among voyagers at sea. We have always held the belief that the pheno menon is solely due to the optical effect, so well known, of a com- plementary colour appearing on the withdrawal of any very brightly- coloured object. If ycu look at the sun and then close your eyes, a brilliant green image will be seen. — Ed. J The late Prof. Howes. We are requtsted to announce that the endowment fund nov being raised for the family of the late Professor (■. H. Howet- F.K.S., will be closed shortly, and all intending contributor; are asked to send their contributions without delay to tht Treasurer, Mr. Frank Crisp, at 17, Throgmorton Avenue. Londor, E.C. Influenza and the Weather. To the Editor of " K.nowledge and Scientific News." Sirs, — In your issue of November there was a most in- teresting article from the pen of Mr. A. H. Bell re the above subject. It is a subject of the utmost importance to the public, for a ravage of influenza has in its tiny germ as deadh- a killing factor as shot and shell in a big war. That Mr. Bell is perfectly right, most doctors who read his article will per- fectly agree. Most will also see in the much abused east wind one of Nature's best antiseptics, .so that instead of being the sower of disease we would rather look upon it as a trying but invigorating friend. True, it may be a dread to the very young, the very old, and to the feeble and confirmed invalid ; but to the great mass of mankind it certainly does not deserve all the scape-goatish epithets flung at it. From personal e.xperience I can corroborate every word written by Mr. Bell, for it has been my fortune, or misfortune, to contend with more than one attack of severe influenza whilst practising in England. In a large country practice I found that in no case did influenza spread e.xcept by the contact of the healthy with the affected. Farmers and their wives had it first, then their families, lastly their servants. Time after time noticing that those who did the marketing were the first to be struck down, con- vinced me that influenza chiefly spread by contact. In the Blue Book which Dr. Franklin Parsons drew up for Parliament when the first severe visitation of influenza some 20 years ago visited Great Britain, there is a report of mine bearing out the opinions so clearly set forth by Mr. Bell in his article in •■ Knowledge." In a conversation I had with Dr. F. Parsons he, too, was fully convinced that climatic changes had little to do with the spread of influenza, and in coming to that conclusion he had his own observant mind guiding him, as well as the e.xperience of others. I am, dear Sir, Yours truly, T. PicKTHORN Thomson, C. S. Duplex, Suez, Egypt. Venom of Spiders. To THE Editor of " Knowledge." Sirs, — I have read with great interest Mr. C. A. Michell's letter relating to the venom of spiders. I have always had great interest in this subject, and have studied it for many years. When I was a boy at school I was very fond of natural history, and used to spend much of my spare time collecting specimens. One day I succeeded in catching a very large black spider, but unfortunately I did not notice the variety. Having nowhere to put it, I placed it in a bo.x containing two frogs. To my surprise ne.xt morning I discovered that one of the frogs was dead and the other very torpid, and succumbed in a few minutes. The spider was quite lively, and when dis- turbed with a straw attacked it furiously. Happening to mention this fact to our old gardener, who had a great reputation in the village for his knowledge of wild things, he declared that the bite of a spider was fatal to all small creatures, but only during a certain part of its existence. Wishing to prove this I tried the next night with another frog. In the morning the frog was dead, but the spider had un- fortunately escaped. I tried several times after this, but these were the only cases in which the frogs were killed. I shall be much obliged if any of your readers can inform me to which variety my spider belonged. I have never since seen one like it. The points that struck me most about it were its great size, its broad, smooth back, and the orange stripe along the lower side of its body. E. T. Z. D. The Elms. 354 KNOWLEDGE & SCIENTIFIC NEWS. [February, 1906. Answ^ers to Correspondents. Altitude of the Sun. In the note in the Januar)' number the decUnation should.of course, read 23- 3' 28" instead of 28° 3' 28", which alters the calculation. B. Lomax. " Baily's Bt-ads." Just before a total eclipse of the sun, and when but a very narrow rim of the sun is visible, this thin line suddenly becomes broken into detached spots of light caused by the irregular (mountainous) surface of the moon. This phenomenon was first noted by Francis Baily in 1836. J. H. The resistance of the air to a surface moving against it is not quite as you put it. The formula should read : P = X' X when P = Pressure in lbs. per square foot. V = Velocity in miles per hour. X = A constant which varies according to different experimenters, but may be taken at about ■003. It is very generally supposed that a bird gains a certain amount of lift even during the upstroke of the wings. There are, unfor- tunately, a large number of inventors anxious to obtain funds for constructing their models, but, considering the very great amount of time and money which, without doubt, must be expended before a successful flying machine can be con- structed, our advice to those not having such commodities at their disposal is to leave the matter alone. REVIEWS OF BOOKS. Nebula to Man, by Henry R. Knipe (Dent and Co. : price £1 is. net). — This is a fine work — original, poetic, and sublime. It treats of the history of our planet from its very birth, and the evolution of life-forms down to mau. Such a subject, so vast in its magnitude, yet so hypothetical in its nature, is appro- priate to verse, and accordingly this history of an eternity forms a great poem, descriptive of what we know, or presume we know, of ages long gone past. The interest and attractive- ness are greatly added to by the profusion of well-designed and well-executed illustrations. Many of them are coloured plates, and represent various scenes in bygone times, from views of nebulie and landscapes in the different geological periods, queer denizens of the earth and waters, down to pre- historic man. yuite a number of artists have contributed to this interesting collection. If the whole is naturally to some extent fanciful, the facts introduced are well authenticated, and the notes at the end of the book supply references to the sources whence these facts are culled. To give some idea of how such a subject is treated in verse, we may quote a few of the opening lines, and if the poetry be not of the highest order, it is, at all events, well-worded and pleasing — A glowing mist, through realms of space unbounded. Whirls on its way. by starry bests surrounded, Dim is its lustre, as compared with theirs, And more the look of stars dissolved it wears. The following, too, may exemplify some of the apposite ideas included — Perchance descended from ihose gauze-winged flies, That flitted joyous 'neath Devonian skies, In places now some butterflies are seen, Gay colours bringing to the sombre green. How great and varied. Nature, are thy powers ! Those monster reptile forms, those flying flowers ! And can it be that in some far back age In one life-form both had their parentage ? We hope this is a correct quotation, although there is an evident misprint in the book in the fifth of the lines quoted above. The Uses of British Plants.— By an oversight we omitted to mention in our last number that this book is by the Rev. Prof. G.Henslow, M.A., and is published by LovclC Reeve and Co. ; price 4s. f)d. net. The Nature and Origin of Living Matter, by H. Charlton Bastian, M.A., M.D., F.R.S., &c. With 245 illustrations from photomicrographs. Medium, Svo. (Fisher Unwin ; 12s. 6d. net).— Dr. Charlton Bastian has produced a work replete with interest. The views expressed, and the conclusions drawn, are not seldom unorthodox ; yet, the author has great respect for the opinions of others, in spite of — and not unnaturally — a decided leaning towards his own, missing no link in the chain of reasoning which will convince the reader of their soundness. The earlier chapters will repay attentive perusal, as leading up to what might be thought the more fascinating problems of " Spontaneous Generation " and the Heterogenetic origins. Dr. Bastian rightly lays stress on the " Uniformity of Nature," as the basis of the hypothesis of evolution, for without this " Uniformity " our knowledge of the past, and insight of the future, would be indefinite and futile. Certainly, Aristotle did not hold this view, nor could it be expected that he should, since it is time alone that has driven " Chance " and " Spontaneity " from their position in nature to be replaced by law and order. Evolutionists generally are not at one with the author's more advanced views on the occurrence of Archiebiosis. The belief of the majority is that living matter came into being once only, and that in the distant geological past. Dr. Bastian has Haeckel and Carl Niigebi with him in the belief that Archie- biosis has been repeated times without number, and also that it arises de novo now. How the formation of organic material from the inorganic is, or was, brought about may remain a profound mystery, whichever view be held. It must be admitted that Dr. Bastian's researches into the natural origin of living matter, from their inherent difficulties, have not, with any certainty, convinced us that spontaneous generation does take place, although his arguments and conclusions, founded on his prac- tical investigations, help us to realise that its existence is not a myth. To hold a biassed opinion on this question, Riicker has well said, is " to beg the whole question at issue ; to decide the cause before it has been heard." Pasteur was convinced of the impossibility of " life existing without an anterior and similar life, " having failed to find proof of it after twenty years' labour. Dr. Bastian is equally positive that Heterogenesis is a reality. Thirty years ago he turned his thoughts to the doctrine of Heterogenesis; the evidence brought forward in its favour, is that of a mature observer, working in Nature's laboratories in quest of her secrets. The conclusions drawn harmonise with the accumulation of evidence arising from ob- servation and experiment, and all that is expected is that they be the subject of impartial consideration. The views advanced do not postulate any inexplicable departure froin the uni- formity of Nature. Before us is a volume which will make thinkers ponder the more, and should stimulate scientists to fresh endeavour to emulate the author in attempting to solve the problem of the nature and origin of living matter. — S. G. M. The Bontoc Igorot, by Albert Ernest Jenks, Department of the Interior U.S. Ethnological Survey Publications; Vol.1. The United States Government is preparing to consolidate its dominion over the Philippine Islands by a scientific survey, not alone of the physiographic aspects of the new territories, but of the anthropological attributes of the peoples who are to be governed. It is an example which may be commended to the notice of the British Government, and the first of the publica- tions of the new survey is in many respects a model publica- tion. The Bontoc Igorots, who are a tribe living in the interior of the northern island of Luzon, were selected for examination; and Mr. Jenks, the Chief of the Ethnological Survey, accompanied by his wife, spent some six or seven months among these primitive people, photographing, measur- ing, observing ; and learning their language. The results are embodied in the work before us, a heavy volume — though heavy only in the physical sense — well illustrated by between one and two hundred photographs, diagrams, figures, and plans. The Bontoc Igorots are a simple race, industrious agricul- turists, with hardly any vices, no pastimes to speak of beyond the stimulating sport of head hunting, and remarkably few beliefs or prejudices. They are good natured, kindlj- and generous ; and they are, one would say, a race well fitted to live long. They are of good physical development, neither tall nor short, fat nor emaciated, and suffering from no organic diseases. Yet — such are some of the paradoxes of the simple life ! — they grow old at forty-five, they are quite old at fifty- February, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 355 five, and hardly ever live to seventy. The only reason which in this bulky and interesting monograph we have been able to discover for their failure to live to a hundred, is in the recipe for one of their beverages. It is called " sa-fu-eng," and is prepared as follows: " Cold water is first put in a jar and into it are thrown cooked rice, cooked camotes, cooked locusts, and all sorts of cooked fiesh and bones. The resulting liquor is drunk at the end of ten days." Mr. Jeuks says that it smells worse than anything else in Bontoc ; and he is puzzled to account for the absence of fatal consequences. To our minds it shows only what fine constitutions these primitive people possess; though the fact of the shortness of their days is still unaccounted for. Of Jack's Scientific Series (T. C. & E. C. Jack ; price is. each) we have received five new volumes. Meteorology, by J. G. McPherson, Ph.D., F.R.S.E., is a handy little book, containing a number of interesting facts in all branches of meteorology. But the composition is not as satisfactory as it might be. There seems to be a strained attempt to make the language simple and childlike, and yet much ot it is far from being clear, even to the intelligent reader. For instance, what is meant (on p. 92) by " The leading winds are under the calculation of the meteorologist, but the others will not be bound by laws" ? It seems rather superfluous to tell us "The soft rain on a genial evening or the heavy thunderstorms on a broiling day are too well known to be written about " (though such sub- jects would seem to be the object of the book), and " Some- times rain is earnestly wished for, at other times it is dreaded, according to the season." Sociology, by C. \V. Saleeby, M.D., is another of the series. Whether " Sociology " can be called a science, and divided into " pure Sociology " and " applied Sociology" is a matter that we need not here discuss, but the author himself does not lay stress on this point, and merely goes ahead to relate in com- prehensible language some of the leading facts which are to be included under this head. Part I. consists of a general survey of society, sexes, and social organism, together with the origin and future of Religious Belief. Part II. deals with such sub- jects as Education, Society and Crime, Socialism and Politics. Two more books of the series are by the same author, Dr. Saleeby, and on very kindred subjects. Heredity discusses modes of reproduction, facts and laws of Variation, Men- delism, and Inheritance. Organic Evolution treats of the Evo- lution of Life, Natural Selection, and one chapter — which will doubtless be generally sought for — on the Future Evolution of Man. Here, the author tells us, we may look for improve- ment. Not only is the intelligent and the conscientious man more likely to gain the admiration of a fellow-woman, but, what is nowadays more practically important, such an individual is more likely to gain a post, giving him the means to marry. Psychology is yet another volume by Dr. Saleeby, and this treats of the Evolution of Mind and Will, Association of Ideas and of Sensations, and ends up with a chapter on Psychical Research. The Voyage of the " Discovery," by Capt. R. F. Scott, C.V.O., R.N., 2 vols. (Smith, Elder, and Co.; price 42s. net). — A book of this nature, a record of three years of travel, and a record which must bear the stamp of an official report, cannot but be bulky, and there is more than this to be included. .\ general history of .Antarctic navigation is a fitting intro- duction to the story, and then a full account of the incep- tion (jf and preparations for this particular expedition must necessarily follow. Once started on the voyage all is plain sailing, and from Christmas Day, 190 1, till September, 1904, an almost daily account of life and adventure in the Antarctic is presented. It will not be necessary here to repeat any of the tale which is told. The book is written in a style that needs no translation, clear, and without technicalities, and the detail of life in those dreary wastes and inhospitable climes is rendered full of interest. Moreover, much of it is exciting reading. Some of the thrilling adventures met with are graphically described, and the accounts of fierce gales howling around the ship fast in the ice, snow drifting deeply and almost burying the whole vessel beneath it, the windmill wrecked and chimneys damaged, but all the while the crew joining in a humorous discussion on •' Women's Rights," are truly exciting and diverting. The naturalist, the geologist, and the meteorologist will find much matter of interest. What with penguins and very many other birds, to say nothing of whales and seals, there is plenty of life to describe, while two Appendices treat of the geological observations, the zoology being contributed respectively by Mr. Ferrar and Dr. Wilson. The numerous illustrations, mostly from photographs, are excellent, and charts of the track complete this very readable and valuable work. Smithsonian Institution Annual Report (Washington: Govern- ment Printing Office). — This report, besides containing the official and financial statements of the Institute, is full of interesting communications on various subjects. These in- clude an account of experiments with the Langley Aerodrome; A paper by Professor Poynting on " Radiation in the Solar System "; a suggestive paper by Sir WiUiam Ramsay on the "Present Problems of Inorganic Chemistry"; one on the " Pearl Fisheries of Ceylon," by Professor W. A. Herdman; and many on ".'\rchasology" (chiefly .American). It is altogether a fascinating volume, attractive to almost every type of reader. Guide to Finger-Print Identification, by Henry Faulds (Han- ley : Wood, Mitchell, and Co., price 5s.). Now that finger- print identification is coming so much to the fore in criminal proceedings, public interest in the subject is naturally great, and this small book provides methods of identification. The author goes to some pains to explain that it is a popular fallacy to connect this subject with the name of M. Bertillon, whose system is wholly anthropometric. He, moreover, has failed to find corroboration of the oft-repeated statement that finger prints have been used for identification in China and else- where. But there seems almost too much space devoted to a collection of evidence to try to prove that the author was the first to introduce the subject. Like most others, this subject has only gradually come forward, and many, but especially including Mr. F. Gallon, have had a hand in giving it the publicity it now enjoys. As a guide to the practice this book is decidedly disappointing, though it contains a number of useful facts scattered among its pages, and is clearly illus- trated, mostly from enlarged photographs. Nature through the Microscope and Camera, by Richard Kerr, F.G.S., F.R.A.S. (London: Religious Tract Society, 1905). — The number of people who find keen enjoyment in the study of the beautiful in nature is far greater than many would sup- pose. .And though such students care little for the things that concern the systematist, they incidentally render him yeoman service. This is especially true of those who pursue the study of the infinitely little in nature, for to them we owe some of the most valuable advances in the evolution of the microscope. This really handsome volume is written especially for those who regard nature as a sort of .Aladdin's cave to be exploited through the microscope. The richness of the spoils to be gathered in such hunting are not easily described, but some idea thereof may be gathered by a glance through the many beauti- ful illustrations which adorn the pages of this work. The store of good things which this cave of living wonders contains is limit- less. Diatoms, and molluscan teeth, caterpillars' eggs, beetles' legs, the stems of plants, and the human skeleton are all shown to contain hidden and unsuspected beauty. Dr. Sims Wood- head has written an admirable introduction to this book, and Mr. Arthur F. Smith has contributed a really valuable chapter on " Practical Hints on Photo-Micrography." Second Stage Inorganic Chemistry (Theoretical), by G. H. Bailey, D.Sc. (Lond.), Ph.D. Edited by W. Briggs, LL.D., M..A., B.Sc.; pp. S and 542; 3rd Edition (London: \\'. B. Clive ; price, 4s. 6d.). — Although this book is primarily in- tended to cover the ground included in the syll.abus issued by the Board of Education it is yet more than a mere " cram " book and can be studied with interest by those who have not the fear of examination ever before them. It has been brought thoroughly up to date, and gives, for instance, a clear summary of recent discoveries about radium emanations and the " contact " method of manufacturing sulphuric acid. The text is illustrated by diagrams and figures of apparatus ; experi- mental work is described wherever possible ; and each chapter has a series of questions which will be found of the greatest use. Future Forest Trees, by .A. Harold Unwin, .Assistant Con- .servator of Forests, Southern Nigeria (T. Fisher Unwin; pp. loS, three full-page illustrations ; price 7s. 6d. net). — This book is likely to be of great utility, in view of the increased interest which is being taken in the question of re-afforestation 356 KNOWLEDGE & SCIENTIEIC NEWS. [Febkuaky, 1906. in our own country. At the end of the iSth century Germany foresaw the importance of introducing certain American trees into that country, about 300 species beinj; chosen. Some of these have become established, and this booli gives an inter- esting account of the experiments tried by the German Government, and also of their failures, and the cause to which failure was due. The question of tree-planting is likely to be an important one in our own country, in view of the rapid disappearance of our forests and woodlands, and the very small amount of re-afforestation which takes place. Here there is good work to be done. In the ranks of the unem- ployed the necessary labour can be found. The institution of " Arbor-Day " is a step in the right direction, but whatever is done in the future, it will prove of great value to have a guide as to what trees will, and what trees will not, be suitable by way of increasing our own tree-flora, and in this useful work there will be found a guide, from experience, ot what experi- ments are likely to lead to failure, and what to success. The Central Tian-Shan Mountains, by Dr. Gottfried Merz- bacher. Published under the authority of the Royal Geographical Society (John Murray, pp. 285 ; 20 illus- trations and folding maps ; price 12s. net). — This mag- nificently-produced volume deals in detail with extensive exploration of the Tian-Shan Range in the years 1902 and 1903. It does not profess to be an exhaustive account either of the range or of Dr. Merzbacher's explorations, but it is sufficient to give an idea of the magnificence of the heights which he scaled, and the grandness of the glaciers which he crossed or viewed. The illustrations are as a rule full page, and are from very fine photographs. From the point of view of the mountain-climber, the book is of intense interest. Elements of Mineralogy, by Frank Rutley, F.G.S. ; 14th edition, revised and corrected. (London: Thomas Murby and Co. ; pp. 251, illustrated.) — We welcome this edition of a well- known manual, packed full with material valuable to the mineralogical student. Particularly to be noted are five pages of very clear diagrams illustrating the various systems of crystallography, and the additional chapter on '■ Radio-.Active Elements," by Ernest Howard Adye. The Fungus Flora of Yorkshire, by G. Massee, F.L.S., and C. Crossland, P'.L.S. (London : A. Brown and Sons, Farring- don Avenue; pp. 396.) — This book is an admirable summary of work done during many years by members and friends of the Yorkshire Naturalists' L'nion. It is modestly claimed that the work is but a "contribution " to the subject of the fungus fiora of Yorkshire. That may be so. but it should serve as an example to other less active local natural history societies. The Preparation of Manuscripts for the Printer. By Frank H. Vizetelly. (Funk & Wagnall's Company ; price 3s.) — Should be a useful book, but as it is written for .-Xmerican readers there is much that is not applicable in English practice, and is therefore apt to confuse instead of enlighten. There are, however, many hints and directions which are universally applicable. Introductory Mathematics. By R. B. Morgan. (Blackie & Son, Limited; price 2S.) — ''This little book is an attempt to include in one cover all the .Algebra, Geometry, and Graphs a bo}' ought to know before he can really be said to have done more than obtain an introduction to Mathematics." Such is the estimate of mathematical knowledge formulated in the preface. It would be more correct to say that a boy must grow up, and go to a university, and take a degree in mathe- matical honours before he can be said to have done so much as obtain an introduction to mathematics — unless that boy happened to be "made in Germany," when he would be initiated into what mathematics means a good deal earlier. But apait from the question as to what mathematics really is, the book appears to be a useful one. It consists mainly of easy exercises in the rules of algebra, slotting on squared paper and ruler and compass work. It thus embodies recent methods of teaching in a book of somewhat more elementary character than the majority. A few things might be improved, thus, after giving a rule for the area of a right-angled triangle, the author gives exercises in which the areas of figures made up of right-angled triangles are found, not by the rule but by the rough and ready method of counting squares. But in his examples the rule does not appear to be applied correctly, several broken squares being omitted that ought to be counted, and many counted that ought to be omitted. The results arc not necessarily correct to the degree of approximation postu- lated in requiring boj s to waste time in sharpening hard pencils to chisel-points. This last requirement (tor which the author is in no way responsible) is calculated to lead to mis- chievous results later on, when boys ought to learn that the best drawn figure is only approximate, and that verifications by geometrical construction are not the same as proofs. But it must be claimed that the book puts a boy in the right way of getting a knowledge of what a great many people call mathematics, and what it is important for everybody to know. Wellcome's Photographic Exposure Record and Diary. (Bur- roughs Wellcome and Co., London ; price is.) — To the many who know this note book and diary it is only necessary to say that the volume for this year retains all its well-known features, while it is brought quite up-to-date in such tables as those of plate speeds, and has an improvement or two that add to the convenience with which it can be used. To any who have not seen it, we may say that it is a pocket diary of convenient dimensions and thin, one page to a week, with other blank pages for memoranda, and ruled pages for the record of as many negatives and prints as any photographer other than a trade worker or professional portraitist is likely to need, be- sides a great deal of letterpress information and an ingenious exposure calculator. The general information of the ordinary kind is compactly arranged, and the special information gives such details as photographers are most likely to need, in- cluding a system of judging the exposure necessary for making a negative under almost all conceivable conditions. The details of other photographic operations are given in terms of the firm's well-known " tabloid " preparations, but the directions are free from even the slightest evidence of a desire to advise the use of chemicals when they are not wanted. A photographer who needs elementary advice, or anyone who wants to develop and print away from home, may be assured that he will find sufficient information here. Nature in Eastern Norfolk, by Arthur H. Patterson" (London : Melhuen and Co., 1905.) — Throughout the length and breadth of the land the haunts of our native birds are being steadily and swiftly encroached upon. Game pre- serving, drainage, and the builder have done, and are doing, a deadly woik, and those of us who find delight in the wild- places of nature are left lamenting. Time was, when Norfolk was a veritable Avian Paradise. To-day, we turn sorrow- fully to the remnant that is left us, wondering how long even these will succeed in holding their own. This being so, it is fortunate Ihat in these evil times there should have arisen an observer like Mr. Patterson. With the zeal of the enthusiast he has gathered together a rich harvest of facts relating to the " good old days " from the lips of the grey-beards who passed their time amid these vanished and vanishing birds and their haunts. Of these old men some have passed the '■ harbour bar " already, while the survivors are being coaxed by the author into making him the repository for their remem- brance of happier da3's. How much they have to tell that is worth knowing those who have read Mr. Patterson's earlier book, reviewed in these columns a few months since, will pro- bably rememfier with pleasure. The volume which he has just given ns may be regarded as a supplement to this. And it is in every way a worthy supplement. It is this, and some- thing more ; for it is packed with most valuable field-notes of their author's own making : shrewd observation, tersely ex- pressed, on birds, beasts and fishes. It is altogether a charming book, tastefully bound, and well illustrated. W. P. P. Eggs of British Birds, by W. J. Gordon. (London : Simpkin, Marshall and Co.) — It is impossible to say anything favourable of this book. The coloured plates are crude; the writing is slipshod, while the list of " British Birds, Past and Pretent," seems designed rather to fill up space than to serve any useful purpose. But worse than all, purchasers will find that " par- ticulars as to the measurement, colour, and occurrence of the eggs " will be found in another book 1 ! ! W. P. P. February, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 357 More Natural History Essays, by Graham Renshaw, M.B., F.Z.S. (London: Sherratt and Hughes, 1905.) — The author presents us in this volume with a series of extremely interest- ing essays on some of the more remarkable mammalian types. Herein will be found much valuable information culled from old and long-forgotten records, as well as a few things that are new, at any rate, to the non-professional zoologist. Mr. Renshaw writes with an easy grace that lends an additional charm to all that he has to say. Tastefully bound, and well illustrated, this is a book that should find many friends. We note some omissions, however, the most important, perhaps, being the absence of all reference to Mr. F. A. Lucas's valu- able summary on the e.xtmction of Steller's Sea Cow (lihytma Stillcri) ; as well as the investigations of Dr. Stejneger on the same subject. W. P. P. A Glossary of Botanic Terms, with their Derivation and Accent, by B. D. Jackson. (Revised edition, ys.Gd. net, 8vo. pp. 371 : Duckworth and Co.) — In the tirst edition of the work under consideration, the author commences with a quotation from Dr. Johnson, " Every other author may aspire to praise, the le.xicographer can only hope to escape reproach." The early demand for a second edition should convince the author that he has escaped reproach ; in addition, it may be stated that he merits praise for the production of a book of reference in- dispensable to everyone interested in the study of botany from any standpoint. In compiling a Glossary, discrimination can- not be exercised to the same extent as in other cases, hence out of the 16,000 terms defined in the second edition, the same organ is sometimes met with under different names. This condition of things is to a great extent the outcome of personal vanity or self-assurance. An author dealing with a structure already indicated by a recognized term, too frequently con- siders it necessary to coin a new one, often for reasons only apparent to himself. Nevertheless, such new terms must be duly chronicled in a Glossary. Oecology, or the study of plant life in relation to environment, a somewhat new phase of botanical investigation, has necessitated a considerable number of new terms which are here for the first time included in a Glossary of botanical terms. The author, however, felt compelled to draw the line at such compounds as " Carex- Sieversia-Polygonum-coryphium," in thevulgate " Ttie Sedge- smartweed Alpine meadow formation." This is an American production ; it might have been German. As most such com- pounds have been coined by one person, a reference to the work where they occur is given. There are no illustrations, hence the leaves consist of paper, and the book is light and pleasant to use. The type is excellent, and the key-words are not in- dented, but readily catch the eye. Creatures of the Night, by A. W, Rees. (London : John Murray, pp. xix. + 44''^. illustrated; price 5s. net.) — If only the author had avoided the senseless and irritating habit of designating animals by such titles as " Vulp the Fox " and " Brock the Badger" (he might just as well say '• Badger the Brock"!), he would have succeeded in producing a charming book. As it is, these names get on our nerves ; but we may hope that they will not have the same effect on other readers. Mr. Rees is a keen observer of Nature and a thorough lover of animals ; making little ado about sitting up half the night to watch a badger peer forth from its earth, or an otter steal out of its holt. To many of us such vigils would be deadly wearisome ; and naturalists therefore owe a debt of gratitude to tlie author, for if we are to arrive at a thorough knowledge of the habits of animals, it is essential that the creatures should be thus carefully watched in their native haunts. I^ritish mammals of nocturnal habits form the main subject of the book, the otter, badger, fox, hare, hedgehog, and water and field voles (why does not the author call them by their proper country names — rats and mice?) forming the chief items; and in each case the life-history is charmingly written. Owls, nightjars, &c., are taken into consideration in the last chapter. In re- ferring on page 441 to the object of the dark and light stripes on a badger's face, the author writes as though he were record- ing a new fact, which is not the case. The articles originally appeart^d in the Stamlard ; but the re-publication in their present altered and expanded form is a distinct gain to natural history. The Source of the Blue Nile, by A. j. H.ayes. (Loudon : Smith, Elder and Co., pp. xi. -f 315.) — This work is in the main a record of the journey of a small expedition dispatched by the Egyptian Government to Lake Tsana, in Western Abyssinia, to which the author was attached as medical officer; the out- ward journey being by way of the Sudan, while the return route was to Egypt along the Atbara valley. Western Abyssinia is a country but little known to Europeans, and the author and his party traversed one district where white men had apparently never previously been seen. Western .'Vbyssinia, as is pointed out in the preface, dominates the adjacent dis- tricts of the Sudan, and the importance to Great Britain of the continuance of good relations with the Ethiopian Empire is therefore self-evident. In addition to the narration of the journey, the book contains a number of observations on the religion, customs, &c., of the Abyssinians; and antiquarians should be much interested in a photograph of early paintings in the church at Bahardar Georgis. P'rom the limited amount of available carriage, natural history collecting could be carried out only to a small extent, but Dr. Hayes was enabled to bring back a series of insects, which Professor Poulton describes in an appendix as being valuable and interesting from a distributional point of view. A few specimens of larger animals obtained by the author are shown in reproductions from photographs, among these being the "head of a harte- beest." This is a somewhat vague term, and the author might surely have found a naturalist friend to tell him that the speci- men belongs to the tiang (Daiimliscus corriguiii Hang), an ante- lope which can only be called by courtesy a hartebeest, of which group it is a very aberrant representative. To all inter- ested in adventurous travelling and the opening-up of Africa, Dr. Hayes's volume may be cordially commended. Magnetism and Electricity for Students. H. E. Hadley. (Macmillan and Co., 6s.) — The scope of this volume is, roughly, that required to pass candidates for the B.Sc. exami- nation of the University of London, and by students working for stages II. and III. of the Board of Education examination. The author has succeeded in compressing a very large amount of instructive information into its 575 pages ; this information is conveyed wherever possible with the help of most excellent diagrams. There are a large variety of questions set at the end of each chapter which are selected, in the main, from examination papers. These will prove very useful, but their utility would be increased, especially to the private student, if answers were provided to more of them. The subject matter is, as a rule, very correctly presented. Some slips, such as fig. 31. ought to be rectified. This diagram gives an entirely misleading notion of the forces between an iron filing and a magnet. Diagram 54 on the following page indicates lines of force entering and leaving an iron ring (such as a Gramme-ring) much as though the flux was carried on by its own momentum. Teacher'; are exceedingly slow in learning that if the line reaches the iron surface even slightly inclined to the normal, then on the inside of the surface it is very nearly at right angles to its previous direction ; that is, it is suddenly rotated through nearly a right angle. This action is a consequence of the high permeability of iron. In spite of these and certain other inaccuracies and deficiencies we can recommend the book as giving in general a simple and satis- factory account of its subject. Circulating Scientific Library.— Mr. H. K. Lewis, 136, Cower Street, W.C., has sent us a copy of Nos. 23 and 24 of his " Quarterly List " of additions to the circulating library. The lists contain nearly 300 titles, and include many import;int new books and new editions on the various subjects covered by the library. There are brief notes to most of the books which, while not pretending to give the subscriber an exact idea of the book, enable an opinion to be formed on its general scope. The library has been long known as a useful medium for the supply of medical literature, and its extension to cover all branches of general science, commenced some two or three years ago, should add considerably to its value. We under- stand this neatly printed and useful " Quarterly List " will be sent post free regularly to anyone desiring to have it, and should think it would prove of service to all our readers who desire to keep themselves abreast of the important additions to scientific literature. 358 KNOWLEDGE & SCIENTIFIC NEWS. [February, igo6. ASTR.ONOMICAL. By Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S. SeetsonaLl Cha.nges on the Moon's S\irface. Profi;ssok W. H. Pickering has several times suggested that he has obtained photographic evidence of real changes on the lunar surface, and he has recently stated that there will shortly occur a favourable opportunity for critical examination of one of these supposed variable features. This is in connection with the small crater Linne, and the special observations can only be properly made at the time of a lunar eclipse, so that this may be done on February 8 next. While sexeral observers have proved that the size of the white area surrounding Linne is dependent on the time that the sun has been shining on it, or, in other words, on the co- longitude of the sun as seen from' the moon, only four, Douglass, Saunder, Wirtz and Pickering have been able to observe it at the time of a total eclipse. The observers in question all agree that the white spot appears larger after emerging from the Earth's shadow than it did before it entered it. Hence it is very desirable that not only should the number of observations be increased, but definite measures of the extent of enlargement might be obtained if systematic arrange- ments are made. The observation depending on the age of the moon may be made without great ditficulty by comparing a pair of good lunar photographs, one taken soon after first quarter, the other near full moon, when the difference may amount to 2" or 3". In general the higher the sun the smaller is the spot. The observation during total eclipse is not so simple. An attempt was made during the last eclipse visible in America, in October, igo2, but failed owing to lack of co-operation. If observations can be secured this year, it is recommended that for an hour or so, both before and after the shadow transits Linne, as many micrometer measures as possible should be taken, all approximately in a north and south direction, as measures in this position angle are more accurate than others on account of the moon's orbital motion. Owing to the hazi- ness of the edge of the white spot surrounding the crater, it would be advisable to start observations on a previous night to become familiarised with the region. Rather conspicuous changes also occur in the white spots near the centre of Eratosthenes during the course of a luna- tion, and observers not possessing micrometers might en- deavour to detect changes by comparison with neighbouring features of more constant dimensions. Periodica.1 Comets due in 1906. Notice is given by Mr. W. T. Lynn of the expected return of two periodical comets during the present year. Comd Holmes, which it is hoped we shall see during the spring months, was discovered at Islington on November 6, 1892, in Andromeda, and was first thought to be connected with the lost Biela's comet, but this was disproved when its motion was determined. It appeared strange that the comet was not seen about the time of its perihelion passage during August, 1S92, and it has been supposed that a subsequent increase of intrinsic brightness may have taken place. The comet is remarkable for the small eccentricity of its orbit, which lies wholly between those of Mars and Jupiter; its perihelion distance from the sun is 2'2, and that of aphelion is 5-0. The period is about 6'8 years. It was seen on its second return by Professor Perrine on June 11, iSgg, having passed perihelion on April 28. Another return to perihelion will therefore be due in the present year, and may possibly occur in the earlier months of the year. Finlay's Comet, discovered at the Cape of Good Hope on September 26, 1S86, passed perihelion on November 22 of the same year, and with a period of about 6| years, was next seen in 1893 by Mr. Finlay again on May 17, which would be about a month before the calculated time of peri- helion on June 16. At the return in the winter of 1899 the comet was unfavourably placed and escaped observation, and is due during the summer months of igo6. Giacobini's Comet, 1905 (c). This comet has been frequently seen on the Continent, but the unfavourable weather appears to have prevented many observations in England, as it could only be seen some little time before sunrise. Herr Stromgren has computed the fol- lowing elementa : — T = 1906 Jan. 2263 G.M.T. u = 198° 22' Si = 91° 55' ' = 43° 37' q = 02238 The following ephemeris will serve as a guide in searching for the comet : — 1906. R.A. Declination Comparative Brightness. Feb. 2 23 ■■io iC - 8 4 S 20 6 0 13 34 — I 40 b 14 10 I II 28 + 42 N 10 14 I 42 48 8 48 7 18 2 9 5b 12 38 4 22 2 32 ■ib 15 40 3 26 2 52 52 -f 18 6 N ^ Recent Meteorological Determinations by Kites. Although systematic examination of the upper atmosphere is not yet carried out on this side with the completeness adopted in America, where it is chiefly due to the initiative of Pro- fessor Rotch, of the Blue Hill Observatory, we have constant evidence of the tendency to recognise the importance of this somewhat difficult branch of meteorological science. At a recent meeting of the Royal Meteorological Society, Mr. G. C. Simpson described a series of attempts to fly kites for registration purposes from the deck of a mission ship (Queen Alexandra) attached to a deep-sea fishing fleet in the North Sea. The work was carried out during July and August, 1905, on behalf of the joint Kite Committee of the Royal Meteorological Society and the British Association. Eight ascents were successfully secured, and the greatest ele- vation recorded was 5800 feet. Mr. C. J. P. Cave gave an account of his operations in Bar- bados, during April and May, 1905, and from an examination of the traces secured, Mr. \V. H. Dines concludes that the humidity there varied from 60 per cent, at the surface of the ground, rising to So-go per cent, at heights from 1000-2000 feet, and then gradually falling off again to 50 per cent, or less as the elevation still further increases. It is noted that these values are lower than would have been expected in the region over a tropical ocean. The increase is of the normal type, but the maximum value occurs at a far lower elevation than is the case in Europe. Extended observations having shown that it is probable that the relative humidity forms a reliable guide to the state of the vcfrtical circulation, a low humidity indicating a descending current of air, it may be inferred from the above observations that there is a settling down of the atmosphere over the regions of the smaller West Indian Islands during April and May. We believe that experiments are also in progress by the Indian Meteorological Department for exploring the upper atmosphere by means of automatic instruments attached to kites, and if successful it is expected to derive much practical information which should be extremely useful in increasing the accuracy of the weather forecasts so necessary to the welfare of the industries of the country. Intrinsic Intensity of the Solar Corona.. Observing at Burgos on August 30, 1905, M. Charles Fabry determined the intrinsic intensity of various portions of February, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 359 the coronal radiation during the Total Solar Eclipse. Using for comparison an Auer electric osmium lamp, the coronal image given by a lens of I'ao metre focus was thrown on a plate carrying a diaphragm, so that any part of the corona could be examined at will and changes made quickly. The aperture of the objective could also be rapidly altered. It was found that the intrinsic brightness of the corona at a point 5' from the limb of the sun, in the direction of the equator, was about 720 candle power. That of the full moon was found to be 2600 of the same units, so that the intrinsic intensity of the coronal light at the point indicated was about 0-28 that of the lunar surface. This is in good accord with the previous determination by Turner in 1893, who, using a photo- graphic method, obtained the value 0'25. Comparing these values with the measured brightness of the sliy close to the sun during ordinary times, it is found that the corona is probably about 2000 times less intense than the bacliground of illuminated sky against which it is projected, and this indicates the difficulty to be contended with in any attempt to photograph or see the corona during ordinary sun- light. It is possible that certain exceptional stations at high altitudes, and with very dry climate, may offer the least dis- couraging conditions. CHEMICAL. By C. AiNswoKTH Mitchell, B.A. (Oxon.), F.I.C. A Method of Rendering Phosphorxis Ha.rnnless. A NEW process of treating ordinary yellow phosphorus has been patented by M. Bals in France. The phosphorus is mixed while in a melted condition, or as it condenses from the vapour in its manufacture, with a salt which does not decom- pose when melted, c.f;., sodium thiosulphate (" hypo "). The process must be carried out in a vacuum or in an atmosphere of inert gas such as carbon dioxide, so as to prevent contact with the air, and it is also recommended to use a liquid such as petroleum oil or turpentine in addition to the salt so as to coat each fine particle of treated phosphorus with a protective layer of substance that will prevent oxidation. It is claimed that finely divided phosphorus thus treated can be transported and used in the manufacture of matches without risk of injury to the workman. The Toxine of Eel's Blood. A characteristic kind of poison is found in the blood serum of the eel, conger, and certain allied species. It is formed as a normal product during the life of the fish, and in this respect resembles the venom of snakes, which has been shown to be present in the blood as well as in the poison glands. The eel toxine was discovered in 1889 by M. Mosso, who found that it prevented the blood of poisoned animals from coagulating, and since then its physiological properties have been thoroughly studied, notably by Drs. Camus and Gley, and more recently by Dr. Wendelstadt. The serum as obtained from the eel has a slight yellowish-green colour, and retains its toxic power for some time if protected from the light. There is a great variation in the degree of toxicity of the sera from different eels, the season of the year being a factor of considerable importance. The toxine itself has not yet been isolated in even an impure condition, although it has been shown that it has the same general char.icteristics as all true toxines as defined by Ehrlich (" Knowlkugh .\ni) Scientific News," this vol., p. 317). Thus it is destroyed by heat and by strong chemical agents, and can be obtained in solid form without injury by evaporating the serum in a vacuum. It acts upon the respiratory centre, which it paralyses, upon the heart, and upon the nervous system, the general effects being very similar to those produced by snake venoms. It has also an active solvent effect upon the corpuscles of the blood. It is said to resemble snake venom in being harmless when swal- lowed, although Dr. Pennevaria records an instance of a man being poisoned after eating eel's blood. The probable explana- tion is that in that case there was some abrasion of the mucous membrane of the mouth or stomach, by means of which the toxine could gain access to the blood. Dogs are extremely sensitive to the action of the poison, whilst the hedgehog is almost completely refractory. As is the case with all true toxines, it is possible to produce an anti-toxine in the blood serum of susceptible animals, and thus to render them immune against enormous doses of the venom. Rabbits and goats are easily immunised, but it is very difficult to produce immunity in guinea-pigs. The So'Called Gold-Coated Teeth in Sheep. Mr. A. Liversidge has investigated the nature of the "gold " which has frequently been reported to have been found on the teeth of sheep. The teeth of the lower jaw bone of a sheep examined by him were encrusted with a yellow substance, resembling iron pyrites, the thickness of the deposit being less than ,'2 of an inch. The incrustation was brittle, and could be removed in scales, leaving a black surface. When examined under the microscope the scales were seen to consist of thin translucent pale brown layers, but did not show any organic structure. They were partially soluble in dilute hydrochloric acid, and when heated turned black, leaving a residue consist- ing chiefly of calcium phosphate. The incrustation thus ap- pears to be a deposit of tartar, accompanied possibly by slight decay of the surface of the tooth, and the metallic lustre is to be attributed to the reflection of Hght from the different surfaces of the films of the substance. Natural Gas in Western Australia. Prior to last year fire-damp was unknown in the mines of Western Australia, and it then appeared, not in a coal mine, but in a Kalgoorlie gold mine. In drilling a borehole there was, at a depth of 687 feet, a rush of gas which took fire on contact with a candle, and was not easily extinguished. The emission of gas continued for a month and then ceased, safety lamps being meanwhile used in the mine. Samples of this gas ha\e been examined by Mr. E. Mann, the Government Analyst, and found to consist, in the main, of marsh gas (methane) and nitrogen, with from 5 to S per cent, of oxygen and less than o'5 per cent, of carbon dioxide. It is suggested that there may be some connection between the occurrence of the gas and the presence of a band of graphite schist in the geological formation. Radio-thorium : A New Element. Sir William Ramsay has added yet another element to the long list of those already discovered by him. Radio-thorium, as this new element is termed, was isolated from the radio- active mineral, thorianite, from Ce)'lon {" Knowledge a.sd SciEXTir-TC News," 1905, p. 22S). It is very similar to the rare earth metals, and is distinguished from thorium by forming a soluble sulphate, and from radium by the solubility of its oxalate in ammonium oxalate solution. Its radioactivity is 500,000 greater than that of thorium. Sir William concludes that the helium found in thorianite is derived from radio- thorium, and suggests the following scheme as illustrative of the relationship : Inactive thorium — > radio-thorium — > thorium x — > emanation — > thorium A — > thorium B — > ? — > helium. GEOLOGICAL. By Enw.vRD A. Maktix, F.G.S. CaLrboniferous R^ocks at Rush. Le.wing for the time being his researches into the geology of Anglesea, Dr. C. .\. Matley has turned his attention to the " Carboniferous Rocks at Rush (co. Dublin)," and has laid the results gained before the Geological Society. Dr. A. Vaughan has in the same connection dealt with the " Faunal succession and correlation of the rocks," which extend for a distance of five miles along the coast near Rush. The southern portion of the tract consists of an exposure of about 2500 feet, the range being from the upper Zaphrcntis to the upper Dihtino- pliylliim zones. The Rush Slates are the lowest beds, and are 13S0 feet thick, the characteristic fossil being Zaphrcntis aff. Phillipsi. Above these is the Rush conglomerate group, 500 feet thick. In these conglomerates are found Osdovician and Silurian rock-fragments, together with many inclusions of carboniferous limestone. Above the conglomerates are some 36o KNOWLEDGE & SCIENTIFIC NEWS. [February, igo6. beds, mainly limestones and calcareous shales, which have been thrown into numerous sharp folds and are occasionally in- verted. The highest beds seen were the Cyathaxonin beds, correlated with the Oystermouth Limestone of the South-West Province. Dr. Matley proposes to continue his investigations into the northern portion of this interesting series. R.ocks of the Ludlow District. There are few women geologists of front ranU, and for the matter of that, there are unfortunately but few women geolo- gists at all. The times move on, however, in this respect as in other fields of labour, and, to their credit be it said, the Fellows of the Geological Society raised no objection to the presence of ladies at their meeting at Burlington House, when Miss Gertrude L. Ellas, D.Sc, read a joint paper by Miss I. L. Slater and herself, on "The Highest Rocks of the Ludlow District." Unfortunately every new worker on any given set of rocks thinks it well nowadays either to adopt a new classification or to introduce new names to old rocks. Granted that this may be advisable, or even necessary, on occasion, but there should be great hesitation in doing so, except under sheer necessity, whilst even in such case ex- perience shows that new classifications of rocks seldom be- come generally accepted. In the paper in question, the authoresses give the following classification : — Feet. 1 , ( Zone of Liiigida cornea and ' no to 120 c- J,. 30 to 50 ' Zone of Liit«ula minima. III. Temeside Group. II. Upper Ludlow Group. I. Av.MESTRv Group. 150 to 160 no to 120 40 to 150 75 'o 250 ' Zone of Clwnites striatella. I Zone of RhynchonelUi I iiiicula. -' Zone of Dayia naviciila. I Zone of Conchidium \ Knighti. 515 to 850 A mass of most interesting and technical information is given in the paper, and the remark is made that the main tectonic features of the district appear to be due to the superposition of Armorican movements in rocks with a Caledonian trend, held by some rigid mass to the north, presumably the Long- mynd massif. Wa.ter Supply. The cry for new water supplies to satisfy our ever- increasing town populations is heard now in one direc- tion and now in another. Near London there are so many draughts made upon the chalk both for private and public supplies, that Ihe water-level is steadily diminishing, besides which there is the fact, not yet satisfactorily explained, that while one deep boring will yield a bountiful supply another a mile away results in disappointment. Croydon has been fortunate hitherto in sources of supplies at her very doors, but in order to allow for the necessities of a further increase of her present population of 150,000 persons, the local authorities are anticipating an expenditure during the next ten years of nearly a quarter of a million, in order to tap fresh sources of supply. To do this, it will be necessary at length to go outside the borough borders, special stress being paid in the selection of a site as to whether or no the chalk is covered by a sufficient depth of tertiaries to form a suitable filtering medium. It is a matter of opinion as to what quantity of the water obtained actually passes through the overlying deposits, and when those fertile fissures are struck, which water-borers eagerly anticipate, the probabilities are that a very small quantity of the water thus gained ever passes through the covering at all. The Yorkshire Cliffs. "The Making of East Yorkshire" is a chapter in local geography to which Mr. T. Sheppard, F.G.S., has given his attention, and his booklet on the subject which has reached us is an interesting and popular description of the Yorkshire cliffs, and the coast to Spurn Head, where there are no cliffs to speak of at all. Amongst other remarks, he gives us some idea of the loss of land by erosion by his estimate of the loss of 7 feet per annum throughout a length of 30 miles. Much of the denuded material is helping to extend Spurn Head in a south-westerly direction. "Scree" below Snow^don, Our illustration gives an idea of the scree formed by tumbling of Silurian blocks down the Capel Curig side of Snowdon. It is a subject for consideration when first the "Screu" below Snowdon, scree was formed, whether there is any movement in it now, and if so, at what rate the movement is proceeding. [The Geological Editor would be glad if readers will bear in mind that he is always glad to receive geological and kindred notes for publication, and also copies of papers read before local societies. They can be sent to him, c o Knowledge, or to his address at 58, Whitworth Road, South Norwood, S.E.] ORNITHOLOGICAL. By W. P. Pycraft, A.L.S., F.Z.S., M.B.O.U., &c. The Kea. Parrot a.nd Sheep Sla.\ighter. We have always felt that if there were any truth at all in the stories of the depredations caused by the Kea Parrot (.Ws/oc notabilis) on New Zealand sheep farms, they must be greatly exaggerated. In the Field (Dec. 30), " R. L." gives a brief account of the results of a conference of representative men held recently in Wellington. It would seem that they have been enabled to show that these stories are without foundation in fact. " All the members of this conference were men well acquainted with this bird in its native haunts, but not one of them, either as the result of his own experience, or from the testimony of others, was able to adduce a single item of evidence in support of the alleged sheep-worrying charge." It is well that this exoneration comes now. For years these birds have suffered a grievous persecution, so much so that they are on the verge of extermination. Whether of the remnant that is left enough remain to restock the depleted areas time alone will show. The Protection of SmaLll Birds. We are glad to note that the German Board of .Agricultural Biology and Forestry has taken up the question of the protec- tion of birds useful to agriculturists. Mr. Dunnington Jeffer- son, in the Field (Jan. 13), gives a short account of the efforts that are being made to this end, though we cannot but feel that some mistake has been made concerning his account of the endeavours which are being made by way of tempting insectivorous birds to breed. Not only have nesting-boxes February, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 361 been put up, but according to the authors nests have been supplied to save the birds the trouble of building. " The Department," he .says, " has undertaken the supply of arti- ficial nests suitable' for the different species ... for swallows, moss or a few dead leaves are provided" ! Either the translator has misread some portion of the original account of this work, or the well-meaning authors of these nests have not so wide a knowledge of field ornithology as we should expect. Be this as it may, the provision of nest- boxes, and the efTorts to encourage these birds, is a step in the right direction. In this country the question of the pro- tection of birds is a cause of much difference of opinion ; and we shall never arrive at any satisfactory solution of the problem until the matter is taken up by the Beard of Agri- culture as is done in Germany and .America. Lesser Grey Shrike at Chichester. At the last meeting of the British Ornithologists' Club (Dec, 1905), Mr. A. F. Griffith exhibited a specimen, in autumn plumage, of the Lesser Grey Shrike {Laniiis minor), which had been killed near Chichester in (October, 11)05. Little Shearwa-ter a.t Lydd. At the meeting above referred to a male example of the little dusky Shearwater {Puffinus assiintlis), which had been captured at Lydd. in Kent, was exhibited on behalf of Dr. N. F. Ticehurst. This bird, which marks the fourth occur- rence of this species in Britain, was taken alive after the south-west gale of Nov. 26. Breeding Place of Ross's Gvill. Mr. H.E. Dresser at this same meeting announced the fact that a breeding place of Ross's Gull (Rhudustcthia i-ossi) had been recently found in the Kolyma delta, North-East Siberia. Mr. Bnterlin, a Russian naturalist, the fortunate discoverer, procured an adult bird, young in down, and eggs. PHYSICAL. Bv Altred W. Porter, B.Sc. Instrument for Compounding Vibrations. The following means of compounding several harmonic motions, all taking place parallel to one straight line, is de- scribed by Lord Rayleigh in the Philosopliical Magazine for January. " A wooden batten, say i inch square and 5 feet long, is so mounted horizontally as to be capable of movement only along its length. For this purpose it suffices to connect two points near the two ends, each by means of tn'O thin metallic wires with four points symmetrically situated in the roof overhead. . . . The movement of the batten along its length is controlled by a piece of spring-steel against which the pointed extremity of the batten is held by rubber bands. Any force acting in the direction of the length of the batten produces a displacement proportional to the force. The tracing point by which the move- ments are recorded is at the other cud, as nearly as possible in the line joining the two ponits of attachment of the four suspend- ing wires. The longitudinal forces are due to the vibrations of pi'ndulums hanging from horizontal cross pieces attached to the batten at their centres. The two ends of a wire or cord are attached to the extremities of a cross piece, the bob of the pendulum being a mass of lead (perhaps half a pound) at the middle of the cord. When set swinging the movements of the pendulums are thus parallel to the batten, and tend to displace it along its length." The smoked paper or glass upon which the style leaves a trace must, of course, be given in addition a uniform motion either by drawing it along a guide, or by rotating it in its own plane like the face plate of a lathe. If done in the latter way excellent lantern slides may after- wards be made by photography showing the resultant etTect of combining simple harmonic motions in the way described. If it be required to make the component vibrations have periods in simple proportion to one another, it must be re- membered that the period of a pendulum is proportional to the square root of its length (i.e., in this case the distance of the centre of the bob to the centre of the hue joining the ends of its suspending wires). For example, the elTectof combin ing a note and its octave (which has half the period of the note) can be illustrated by having two pendulums only, whose lengths are, say, 4 feet and i foot. Active Deposit from Radium. Dr. H. L. Broasoa shows (i) that temperatures between 700° and II 3o' C. do not psrmaneatly afifect the rate of decay of the active deposit from radium; (2) That radium B and not radium C has the longer decay period ; (3) Thit the pre- vious values of twenty-eight and twenty-one minutes are both too large for the decay periods of radium B and C respectively; and that twenty-six and nineteen minutes are much closer to the true values. ZOOLOGICAL. By R. Lydekker. Regenerai-tion in Mammals. At the December meeting of the Zoological Society was ex- hibited the skeleton of the tail of a dormouse showing distinct evidence of reparation after an accident ; this being apparently the first recorded instance of the regeneration of bony struc- ture in mammals. 1 he re-formed vertebra, which had assumed the form of a slender rod, was composed externally of true bone, whereas in the regenerated tails of lizards the new structure consists of calcified fibro-cartilage. Spicules of Sponges. A remarkable instance of diversity of view is exemplified by two explanations which have recently been offered of the function of the triradiate mineral spicules found in many sponges. A writer in the Xo\ember issue of the American Saturalist tells that these structures at first merely took the form of small spiny developments in the flesh in order to prevent sponges from being eaten by other creatures. .As time went on these spicules were carried to the perfection of symmetrical devel- opment by what the author is pleased to call " momentum," that is to say, the continuance of development along a particu- lar line long after any useful result accrues to the animal in which such evolution takes place. By a curious coincidence, in the Quarterly Journal of Microscopical Science for the very same month, an English naturalist points out that these tri- radiate spicules are probably a special adaptation to prevent the stems of slender sponges from being broken by the action of the waves of the shallow water in which they grow ; the tri- radiate form affording protection in three different planes. The moral of this is, Never affirm a structure to be useless unless you are absolutely sure there is no possible purpose it can serve. Fossil Flying-fishes. Fossil flying-fishes form the subject of an interesting and well-illustrated communication by Dr. O. .Abel to the Vear- Book of the Austrian Geological Survey. .\t the present day there are two distinct types of flying-fishes, namely, the flying- gurnards and the flying-herrings, the latter being what may be called the typical flying-fishes ; and it is quite evident that each of these has acquired its powers of flight quite independently of the other. Similarly, Dr. .Abel shows that in past geological times several kinds of fishes, totally distinct from the modern types, possessed long pectoral fins, which were intended, in all probability, to enable their owners to skim the surface of the water in flying-fish fashion. The earlier of these fishes — Thoracopteriis and Gii;antoplenis — occur in strata belonging to the period of the Trias, or New Red Sandstone, and, like their non-flying contemporaries, had their bodies encased in an irmour of quadrangular enamel-covered scales. Papers Rea-d. At the meeting of the Zoological Society held on Decem- ber 12, Mr. 11. R. Hogg read a paper on South African spiders of the family l.ycosiiiir : Mr. O. Thomas discussed mammals collected in Persia, describing a new genus and ipecies of hamster-like rodent allied to the North .-Vnierica Pero- inyscus; colour-variation in a beetle formed the subject of a connnunication by Mr. L. Doncastor : the Society's Prosecter discoursed on new worms ; Dr. de Man described a crab and a orawn from Christmas Island ; the heredity of webbed feet in pigeons was discussed by Mr. Iv. S. Browne ; while Messrs. W'arbuvton and Pearce gave an account of new and rare British Oribatida:. 362 KNOWLEDGE & SCIENTIFIC NEWS. [February, 1906. Conducted by F. Shillington ^Scales, b.a., f.r.m.s. Elementary Photo-micrography. {Continued from page 336.) The axis of the microscope should point straight down the camera baseboard towards the light, parallel with the sides; it must be truly horizontal and the disc of light should appear exactly in the centre of the ground-glass screen. Now remove the objective and the ground-glass screen and look straight along the tube, and then adjust the illuminant until it appears in the centre of the limited field of view. Next move the camera up in its slides until there is room for the head to be placed between it and the microscope in order to enable the eye to look down the tube. It is a conveni- ence in this respect if the whole portion of the camera base which carries the microscope, lamp, Ike, rotates on a pivot to one side. We have now got the microscope in the place it will occupv in photographing, and we have also got the source of illumination approximately centred, but have still to centre the sub-stage and auxiliary condensers. First centre the sub-stage condenser. This is done in the usual way by using an ordinary eye-piece and a fairly low-power objective, say one inch, closing the iris-diaphragm as much as possible, and racking the body-tube up or the condenser down until the edges of the diaphragm appear in the field, so that the small central disc of light can be centred with the centring screws. Then focus the objective upon some suitable slide placed upon the stage and focus the condenser. If the image of the illuminant does not appear in the centre of the field it must be brought there by moving the illuminant laterally and not the condenser. This is sometimes rather a troublesome job as very small ad- justments are required, and the hands cannot reach the light w-hilst the eye is at the microscope tube, so that assistance from a second person is of service. The auxiliary condenser now alone remains to be centred, and this can only be done by means of a cap of brass or blackened cardboard fitting on its anterior face, and perforated with a very small hole. This small hole is focussed by means of the sub-stage condenser, but it is brought central by moving the auxiliary condenser vertically or horizontally, and again not by re-centring the sub-stage condenser. Care must be taken that the auxiliary condenser is set true and square with the long optic axis, to which we have so carefully adjusted everything. It must then be decided at what distance from the lamp the auxiliary condenser shall be placed, whether to give parallel or convergent light, and if the latter, where the light shall come to a focus. The ex- periments with the white paper will prove very useful here. The blackened disc is, of course, removed after the centring, just as the iris-diaphragm of the sub- stage condenser is re-opened. On examining the ground glass screen, a bright and uniformly illumin- ated disc should be observed in the centre of the screen. Of course, with a one-inch objective the sub-stage con- denser will probably not give a big enough field of light, in tliis case the top lens can be removed. (To be continued.) Royal Microscopical Society. December 20, at 20, Hanover .Square, Ur. Dukinlield II. Scott, F.K..S., president, in the chair. 'Hie Presi- dent called attention to a donation of slides prepared by .\ndrew Pritchard, about 50 years ago, presented to the Society by Mr. N. I). F. Pearce, which were ex- hibited under microscopes in the room. Mr. Rheinberg called attention to an exhibit consisting of about 20 photographs of diatoms, taken by the Zeiss apparatus designed by Dr. .August Kohlcr, of Jena, for photo- micrography with ultra-violet light, having a wave- length of 275 MM (see '■ Knowledge " for June, 1905, p. 138). Tlie photographs were taken with a 1.7 m.m. monochromatic objective of 1.25 N..'\., using light from the cadmium spark, and having a resolving power equivalent to a N.A. of 2.5, with an objective used with ordinary light, were such possible. There were photo- graphs of Surirella gemma, and Amphipletira peUucida, one of the latter, taken with oblique illumination, show- ing the diatom clearly resolved into dots. Photographs of the same diatom taken with a 2 m.m. apochro- matic objective of 1.4 N..\., and light from the mag'- nesium spark (x = 383 mm), and at the same magnifica- tion, i.e., 1800 diameters, were shown for comparision, and the difference was very apparent. Mr. Curties said that this was not the first time A. pcUucida had been resolved into dots, for he remembered such a photograph being made by Mr. Gifford, whilst Dr. Spitta showed the diatom itself at one of the Society's meetings, but the resolution in these cases was less distinct than in the photographs now shown by Mr. Rheinberg. Mr. D. M. S. Watson read a paper on " .\ Fern fructification from the low-er coal measures of Shore, Lancashire," and exhibited a large section of the coyJ under the microscope, also lantern slides to illustrate the paper. In the ensuing discussion, the President, Professor F. W . Oliver, and Mr. E. A. Xewell Arber, took part. Quekett Microscopical Club. The 426th ordinary meeting was held at 20, Hanover Square, \V., on December i^, the President, Dr. li. J. Spitta, F.R.A.S.. F.R.M.S.,^in the chair. Mr. Bryce read a description by Mr. J. Murray, of a new Bdeiloid Rotifer, from Upper Sheringham, Nor- folk, under the name of Callidina vesicularis. It some- what resembles the well-known C. qnadriccrnifera. Tlie President then delivered a paper on " Some Ex- periments relating to the Insect Compound Eye." -After some preliminary remarks, he reminded his hearers of the general formation of tlie human eye, laying especial stress on the extremely delicate nature of the retina. Considering the insect compound eye, he said one of the chief differences to^ be noted was that, in the human eye the retina was separated from the cornea by a lens (not to mention two fluid media), while in the insect, the retina was in actual contact with the back of the cornea. He suggested that there was no real lens at all in the eye of most insects, and quoted the last edition of Dr. Packard's " Entomology" in support of his statement. He believed that the cornea might be considered as a series of .sm;dl holes. The lecturer then reminded his audience how the multiple images of the so-called insect-eye were ob- tained in the microscope, and attention was drawn to the fact that, to make the experiment, only the cornea of the eye is used by the microscopist — the soft parts being usually w-ashed away, or otherwise destroyed in the mounting. .After referring to several of the difficul- ties met with by those who accepted the orthodox February, igo5.] KNOWLEDGE & SCIENTIFIC NEWS. 363 theory on the subject, the President said that, in his opinion, all these difficulties, anatomicaJ, physiological, and physical, mig-ht be swept away by regarding each facet as a little hole (possibly filled with a simple non- refracting material). After dealing with various points connected with this suggestion, the lecturer went on to describe an experiment he had made which seemed to support his contention very strongly. A photograph of a piece of perforated zinc was made, so \ery much reduced as to almost require a lens to see the holes. This little artificial cornea was then placed on a, microscope stage and a very small cross marked on the mirror below. A slide then thrown on the screen at once displayed the multiple image effect pro- duced by these artificial means. A very interesting discussion followed the lecture. Gordon's Appa-ra-tus for Photo- micrography. Many microscopists must have often desired some simple form of photo^micrographic camera which could be readily applied tO' a microscope, with little re-adjust- ment, to obtain a photograph of some object which is being examined visually. Mr. J. W. Gordon has de- signed a small camera for this purpose, which, whilst not differing in principle from other cameras of the sort, such as that made by Mr. John Browning, con- tains several original and useful features. Briefly, the camera consists of a circular brass tube (A) about six inches long, which is placed over the microscope C3epiece. At the upper end of the tube a small cap (B C) contains a photographic plate, in size one quarter of an ordinary lantern plate, i.e., i|-inch squiu-e, giving circular pictures i|-inch in diameter. Between this and the eyepiece is a projection lens focussed upon the plate, and there is also a small ex- posing shutter (D). Such a camera can be kept close at hand during one's work, ready for use at any time. If the observer's sight is normal, the photograph will be sharp when the microscope is focussed for ordinary vision, but as most people have some slight abnormali- ties of vision, a duplicate tube (E), with a high-power focussing eyepiece, is supplied. Tliis is first placed on the microscope, in order to focus, and then merely replaced by the camera. A small flange (F), fitted over the upper end ol the microscope, forms a table upon which to rest the camera. It has been found that microscopes used in an upright position for photo- micrography, have a tendency tO' move slightly down- wards, and to prevent this a small metal block (G) is provided, which fits above the coarse adjustment and clamps the tube in any position. The principle of this clamp is so simple thai one wonders it h:is not been thought of before. It can be made to fit any micrcv- scope, and should be equally useful in preventing broken slides at microscopical exhibitions. The whole apparatus is noticeable for its extreme simplicity, ease of adjustment, and moderate price, whilst the two photographs reproduced herewith will show what Tongue of Blosvfly. Pleurosigma Formosum. the resulting photographs are like. 1 may add that tliese photographs were taken with a Welsbach gas lamp, and a yellow screen, with exposures varying Irom 20 to 60 seconds. The apparatus is made bv Messrs. R. and J. Beck, Ltd. Microscopic Shdes. Messrs. Clarke and Page, of 104-106, Leadenhall Street, E.G., have sent me four very beautiful slides of marine objects. The staining and mounting show the structures to unusual advantage, and the prices are moderate. Messrs. Clarke and Page bought the stock of Mr. Jas. Hornell, which was, of course", limited, and I understand that these slides are their own mountmg to replace his stock. They have sent me, at the same time, a catalogue of mounted slides, and if those I have seen are representative, they have fully main- tained the high standard set by Mr. Hornell. Notes arvd Queries. W. Bimll, Kilmarnock. — All slides mounted for examina- tion by transmitted light, that is, all transparent slides, can be readily shown upon a screen by means of a projection micro- scope, and they will, of course, thus retain the'.r proper colours. But, unfortunately, such a microscope is rather an expensive apparatus, as the ordinary microscope is not suitable. A lantern is needed with a po\yerful source of illumination; nothing weaker than the oxy-hydrogcn light is any good, and at a distance of more than a very few yards from the screen the arc light becomes necessary. Even with this last powerful light the ditficulties become serious with the higher magnifica- tions given by immersion lenses, but the oxy-hydrogcn light is quite satisfactory for moderate distances and moderate powers. Then special parallelisers and condensers are necessary to supplement the condenser of the lantern. The microscope itself does not differ materially in principle from an ordinary microscope except that its body-tube is neces- sarily very short. I am afraid, therefore, your most economical method would be to make lantern slides of the objects you wish to show. You could, however, of course content yourself with borrowing as many microscopes and lamps as possible, and showing the slides after the reading of your paper. This is commonly done at meetings. Hand-microscopes, which can be handed round, are far from satisfactory. S. P. Miimmiiy, London, and E. J. Addcrley, Hull. — I regret that owing to pressure on my space answers to your queries must be held over for another month. [Communications and Enquiries on Microscopical mattirs should be addressed to F. Shillington Scales, "Jersey," St. Barnabas Road, Cambridge] 364 KNOWLEDGE & SCIENTIFIC NEWS. [February, 1906. The Face of the Sky for February. By W. Siiackli;ton, I'.K.A.S. The Sun. On the ist the Sun rises at 7.42 and sets at 4.46 ; on the 28th he rises at 6.51 and sets at 5-35. Solar activity is well maintained, and on almost any day spots and prominences may be observed. The position of the Sun's axis and equator is shown in the followint' table : — Date. Axis inclined from N. point. Centre of disc S. of Sun's Equator. Feb. I ,, II ,, 21 . . ,,28 12° 0' W 15° 55' W 19° 17' W 21° 16' W 6° 7' 6° 43' 7° 5' 7° 13' There is a partial eclipse of the Sun on the 23rd, in- visible in this country, but visible in the Antarctic and S. Australia. The Moon : — Date. Phases. H. M. Feb. I .. .. 9 ■■ „ 16 .. ,. 23 .. J) First Quarter 0 Full Moon d Last Quarter • New Moon 0 31 p.m. 7 46 a.m. 4 23 a.m. 7 57 a.m. Apogee Perigee I 6 p.m. I 10 12 p.m. There is a total eclipse of the Moon on the gth, but it takes place in the early morning shortly before sunrise, and is only partly visible in this country, the Moon set- ting totally eclipsed. The particulars are as follows : — h. m. First Contact with Shadow, Feb. Q, Beginning of Totality, ,, ,, End of Totality, „ ,, Moon Sets, ,, ,, Magnitude of eclipse (Aloon's diameter = i) i'632, OCCULTATIONS : 5.57 a.m. 6.58 „ 8.36 „ 7-30 Disappearance. Reappearance. 1 Moo:is Mean Time. Angle fromN. point. Mean Time. Angle fromN point. Age. Feb. 3 Aldebaran. . ri pra. 5-23 40° p.m. 6. 28 287° d. h. 10 I .. 4 .1 4 ,. 7 115 Tauri . . .. 120 Tauri . . . . ( Cancri . . . . 5'4 5'3 4'7 5-25 9-54 7-7 lOS^ 18° 60° 6-33 10.26 8.4 a.m. 12.12 232O 331° 308° II 5 14 2 ., 10 X Leonis . . . . 4-7 n.7 134° 269° 17 6 >. 28 ,L Ceti 4'4 7.0 54° 8.9 271° 5 II The Planets. — Mercury (Feb. i, R.A. 20'' 4™; Dec. S. 22" 3'. Feb. 28, R.A. 23I' ym ; Dec. S. 6" 48'). The planet is in conjunction with the Sun on the 20th, and is practically unobservable throughout the month. Venus (Feb. i, R.A. 20'' 45™; Dec. S. ig° 10'. Feb. 28, R.A. 22I1 57"! ; Dec. S. 8° 13') is in conjunction with the Sun on the 14th ; towards the end of the month the planet is an evening star in Aquarius, but not well placed for observation. Mars (Feb. I, R.A. 231151m; Dec. S. r 31'. Feb. 28, R.A. i'' 5"!; Dec. N. 6' 46') may be observed, shining like a reddish star, in the exening sky looking S.W. The planet is situated in the constellation Pisces and sets about 9 p.m. throughout the month. On account of his small angular diameter he is not a very suitable object for observation in small telescopes. Jupiter (Feb. i, R.A. 3I' 38m ; Dec. N. 18^42'; Feb. 28, R.A. 3'' 47'"; Dec. N. 19° 17') is a very conspicuous object in the evening sky ; near the middle of the month the planet is due south about 6 p.m., and is both well placed and easy of observation. The equatorial diameter of the planet on the i3th is 4o"'8, whilst the polar diameter is 2"-f) smaller. The following table gives the satellite phenomena observable before midnight : — ^ |4 g g c Si 6 S P — B p m c P.M.'^. a w £ PM.'s Q U) i P.M.'s Feb Feb Feb I Oc. D, 8 47 0 Sh. E. II 23 18 II. Oc. D. 8 21 2 Tr. I. 5 57 II. Tr. I. II 27 Oc. R. II I Sh. I. 7 15 10 Ec. R. 8 40 Ec. D. II 4 Tr. E. 8 II II Oc. R. 8 25 20 Sh. E. 8 43 Tr. I. 8 S2 Ec. D. 8 28 22 III. Oc. D. 7 54 Sh. E. 9 28 Ec. R. II I III. Oc. R. 10 0 II. Tr. E. II 29 13 Sh. E. 6 5 23 Tr. I. II 41 II. Sh. I. II 29 15 III. Ec. D. 9 22 24 Oc. D 9 ' 3 Ec. R. 6 44 111. Ec. R. II 13 2S Sh. I. 7 29 4 II. Ec. R. 8 24 lb Tr. I. 9 45 Tr. E. 8 24 III. Tr. I. 10 6 Sh. I. II 5 Sh. E. 9 43 8 III. Ec. R. 7 II Tr. E. II 59 II Oc. D. Oc. D. 10 41 17 Oc. D. 7 4 26 Ec. R. 7 0 P Tr. I. 7 51 Ec. R. 10 36 27 II Tr. E. 8 41 Sh. I. 9 10 18 Tr. E. 0 28 11 Sh. I. 8 43 Tr. E. 10 4 Sh. E. 7 48 II Sh. E. II 21 " Oc. D." denotes the disappearance of the Satellite behind the disc, and " Oc. R." its re-appearance ; " Tr. I." the ingress of a transit across the disc, and " Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across the disc, and " Sh. E." its egress. Saturn (Feb. i, R.A. 22'i 21™; Dec. S. 11° 58'. Feb. 28, R.A. 22ti 33"; Dec. S. 10° 47') is in conjunc- tion with the Sun on the 24th, and practically unobserv- able throughout the month. Uranus (Feb. 2, R.A. 18'' 29m; Dec. S. 23° 33') is a morning star, rising about 5 a.m., near the middle of the month. Neptune (Feb. 14, R.A. 6'i 34"'; Dec. N. 22 16') is due south at 8-58 p.m. on the 14th. The planet is situ- ated in Gemini, but is difficult to identify among the numerous small stars in the same field, when viewed in a 3-inch telescope. Meteor Showers : — Radiant. Near to Characteristics. Date. R.A. Dec. Feb. 5-10 . . 15 •• , , 20 . . 75° 236° 181= + 41" + 11° + 34° 1) Aurigae I a Serpen tis Cor Caroli Slew ; bright. Swift; streaks. Swift; bright. Algol may be observed at minimum on the 7th at 9.36 p.m., loth at 6.25 p.m., and 27th at 11. 18 p.m. Double Stars. — Casta/', separation 5"'8, mags. 2-7, 3-7. Excellent object for small telescopes. The brightest pair to be observed in this country ; can always be relied upon as a good show object. K Geminorum, separation 6"-^, mags. 4, 8'j ; very pretty double. J Cancri, separation i"'i, 5"'3, mags. 5'0, 5'7, 5-5 ; with small telescopes the wider component is readily seen. '' Draconis, separation 61 •;, mags. 4-6, 4-6 ; a pretty and easy double, can be separated by observing with a pair of opera glasses. February, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 365 SUPPLEMENT. London's TroLnsformatiorv. A Suggestive Sketch of Da-ys to Come. [Contimted fvoiii page 342.) By Tems Dyvirta. [Cornelius Tiisli was a great American financier, whose modes of business were perhaps not always quite abovesuspicion. He had hit upon the great idea of diverting the course of the Thames so as to cause the river to flow away to the country, and leave its dry bed in London available for building sites. He had made business arrangements with a number of people, had formed a large Company to make the deviation, and finally the work was completed. Tush, however, was sorely disappointed with the treatment he had received in England, where many pecple looked askance at his methods, and had returned to America.] CHAPTER XI. America. The United States wore .simmering, presently thev would boil, but just now there were only indications of the coming excitement. For the time had arrived for the President to make his bow and hand over his grave responsibilities to another caretaker. A rich man can soon make himself popular, at all events, with the mob. A discreet man can always make himself looked up to; if he knows how. At this moment, too, the American people were suffering- from one of their periodical at- tack.= of .Anglophobia. It is dilTicult to say exactly why. I'^ngland had made her.self objectionable in their e\es by successful negotiations which had ended in exten- sive annexations in the Far East. Though their (iovcrnment had raised no formal objection, the citizens of the States felt they had been bested, and, nowadays, with their large and formidable fleet, which had been fostered and greatly increased during recent years, a warlike tone prevailed, which made them long for a chance of showing off their power. Cornelius J. Tush, seeing his opportunity, soon be- came the man of the hour. A judicious and lavish ex- penditure of money, combined with his undoubted power of mind and the high repute in which he had formerly stood, soon brought him to the fore. Tiiere was another factor, too, that greatly added to his popularity. Libcrtia had now blossomed forth into a most beautiful and accomplished young woman, fascinating to all. .She heartily entered into her father's interests, and though still young, had inherited so much sound shrewd- ness that she was able to be of the greatest assistance to him. In due time the pot began to boil, and Tush was nominated as a candidate for the occupancy of the \\'hile House. Haired of England now became the gieat election cry. This, of course, was thoroughly to Cornelius' heart. He hated the English intensely now that he had dug his vast fortune from under their feet. Unforttmately for him this feeling was not vehemently supported by his daughter; she had loved England. The few years she had spent there were some of her brightest (though they had such a melancholy termina- tion), and she looked back on them with feelings of pleasure and admiration. English people had been so kind to her, and it had been of such absorbing interest to watch the great change developing in London with which she was so closely associated. She, pf)or girl, had known nothing then, .-md knew but little now of the awkward scandals associated with her father's name, and she often wondered at his speaking so bitterly of that country which had seemed to her a second home. Not only had Tush succeeded in accumulating \"ast wealth in England, but some of his old speculations in the States had lately brought in considerable sums. Among them was the great ship canal which was now completed and open for traffic between the Atlantic and Pacific. This was at once recognised as a great strategical acquisition from a naval point of view. The United States influence in Mexico, too, had steadily grown, while that of England had for many years as steadily declined, and now it was actually suggested that that country should be incorporated in the States. To all this England had raised strong objections. The Hay-Pauncefort Treaty was continually quoted. The United States Government pointed out that England had, in Jamaica, a base of operations forming a danger- ous obstacle to their use of the canal, that they were entitled to a similar base, and persevered in the negotia- tions. Relations became highly strained, and at this critical moment the presidential election took place. Everyone felt that the result of the election meant peace or war according as the republican, Mr. Sherston, or the democrat, Mr. Tush, were elected. Xever before was there so much excitement over an election. Naturally the anxiety in England was almost as intense as that in the States. In due time the election came about. Tush was re- turned as President by a large majority. The result was inevitable. New York was in a ferment, and every right-down Yankee clamoured for war. England was sullen and depressed. .\r\ ultimatum was sent, an unfavou."able reply returned, and the sword was drawn. " How sharper than a serpent's tooth it is to have a thankless child! " So might Britannia well have wailed. For a feeble old man to see his stalwart son in all his strength is a pleasure, but it is \ery humiliating if it comes to blows and the might of the offspring supervenes. These were the sentiments of the British public when thev heard the news that the entire fleet of the L'nited States had set upon the few vessels we had in West Indian waters and beaten them completely. Pressing through the Ship Canal the .American ves.sels had then gone in pursuit of our Pacific Squadron. The result could clearlv be foreseen. Our ships were mostly scattered about and a long way from ports of refuge. To reinforce them would imply the withdrawal of our ships from nearer home. Australia, however, was threatened, and help must be sent. l'"inally it was decided to send off the \\ hole of the Mediterranean Fleet to the East. Xo sooner was the magnificent Fleet well away in the Indian Ocean than news arrived, scarcely unex- pected, that most of our ships in the Pacific had succumbed to the superior force of the enemy. It was e\ident that our fleet must bo pushed on with all speed, else Australia, or, at all events, her outlying islands, would bo invaded. Many anxious days passed awaiting developments. Meanwhile numbers of troops were being massed and embarked for Canada, and it was hoped that this would create a diversion necessitating the recall of the enemy's na\y. It did so. One day the news arrived that their fleet had repassed through the Panama Canal and was once again in .Atlantic waters. \'et most of our best vessels were on their way across the Pacific after them, and it was now ascertained that the United States, dis- regarditig the noutralitv of the territory, disdaining 366 KNOWLEDGE & SCIENTIFIC NEWS. [February, igo6. their former treaties, were erecting strong- defences at the end of the Canal and wore mounting such guns as would prevent our fleet from forcing its way through. And the position was in other ways very unsatisfactory. Most of our defence ships were convoying our troops to Canada, vet they would hardly be strong enough to resist the attack of the entire United States Navy. Many of the transports with their escorting men-of- war were captured in mid-.iXtlantic, and urgent messages had to be dispatched calling together all ships that could possibly be spared from other places to return immediatelv to the Channel for home defence. The Trans-.^tlantic cables were cut, and direct communica- tion with Canada ceased. It was now evident that a very important naval en- gagement was about to take place, and, as practically all available ships of both sides were concentrated, it should have mo<:t decisive results. Both nationalities were confident of victory, and the movements of the two fleets, sent back by wireless telegraphy, were watched with the greatest of interest. Foreign nations, too, all stood by with bated breath as the two most powerful naval powers closed in the deadly embrace. It was a calm, misty morning, the sea as smooth as a sheet of glass, but with a slight swell on, sufficient to cause a slo\\-, lazy roll on the great leviathans awaiting their turn to enter the bloody arena. Suddenly the news flashed in from one of the reconnoitring destroyers that the hostile fleet was approaching. The British Fleet, responsive to the .Admiral's signals, moved out to meet its foe. Scarcely had the first gun been fired from one of the advanced vessels than the Queen Vicinria, the finest ship in our Xavy, was seen to heel over as a fountain of water flew up at her side, and rapidlv she turned on her beam ends and sunk. Un- doubtedly she had been struck by a torpedo, but whence did that come? Very shortly after another fine vessel went down in an exactly similar manner. The day was not favourable for gunnery, for the haze was so great that ships could not be seen at any distance. The British destroyers dashed boldly forth to launch their torpedoes, but they suffered heavily, for the enemy, awaiting their onslaught, could hear the approaching destrover before she became visible, and were ready with their numerous guns to give the little vessel a terrible salvo directly she appeared in sight. A third of the big battleships having gone to the bottom in the same mysterious way, it was soon conjectured that the cause could be assigned only to submarines. Yet how could these be employed in mid-ocean? Soon the sharp look-out detected one emerging above the surface. It was soon seen to be of vast dimensions. Machine guns were at once trained to bear upon it, but the shots only spattered on the turtle-back harmless as rain. \x\d now for the first time did the British officers realise that the .Americans possessed a huge submarine battleship of the most powerful kind with armoured decks capable of turning aside even the heaviest projectiles. Another terrific report and a fourth splendid vessel became a total wreck. There was but one course to pursue, and that was to sf>eedily flv from this infernal leviathan, and the British sViips turned homeward, pursued by the un- damaged enemy. The game was up. The mighty British fleet, which had for so long ruled the waves, was beaten. The battered remnants put in to various ports around the coast, crest-fallen and vanquished. -All that could be hoped now was that our ships from the far Pacific, hurrving on their homeward journey, and now already passing Malta, would be back in time to prevent any attempt at the invasion of England. But there came the awful news that several of the enemy '.s big ships had bc'^n sighted off Gibraltar, and that the door of the Mediterranean was carefully guarded. \o single vessel dare approach the English coast for fear of encounter- ing the powerful hostile fleet now patrolling around. Frantic efforts were being made meanwhile to prepare to resist any attempt at invasion. Food supply was the great question. .So far most of the Continental routes were still open, guarded by the remnants of our navy. Vast stores were by this means being got into the' country, though purchased at fabulous prices. Every available plot of land wiis being ploughed up to plant wheat. Cattle, imported by the thousand, were being killed off, and the meat preserved, so that the pastures could be turned into cornfields. The great fortifications already constructed around the North Downs were being supplemented by other works. The arsenals, as well as the dockyards, were as busy as they could be. Many of our best troops were either in Canada or had been captured en route. And what with our troubles in the Far East and a small frontier war in India having called away many more, we had but few regular troops left at home. Volunteers, however, came well to the fore, and were being rapidly armed, equipped, and drilled. And meanwhile what was doing in .America? The utmost enthusiasm prevailed. On the receipt of the news of the naval victory, citizens seemed to go quite mad with delight. President Tush, on leaving the Senate, received such an ovation as has seldom before bc'Cn the lot of any man to receive. He was proclaimed \'ictor ! Hero ! Saviour of his country ! His popu- laritv and success were such that he had the whole nation in the palm of his hand and could do as he liked with it. CHAPTER XII. The Invasio.v. One morning the good citizens of London were awakened to hear more alarming news. The .American fleet had steamed up the Channel, driving before it such ships as remained to guard our shores. Follow- ing in the wake of this great squadron were a number of large transports full of troops. These, each having its appointed station, approached various points on the south coast and at once commenced to disembark its human freight. Urgent telegrams were sent hither and thither asking for troops and guns to be at once dis- patched to this or that particular place. But when it became evident that there were some 12 distinct points of disembarkation, it was seen to be impossible to send to oppose each and all. To eight different districts had forces been sent, and these had arrived in time to offer good opposition to the landing ; indeed, in several of these the invaders had received severe defeats and suffered heavy losses. But as more and more messages came to hand of forces landing all along the coast, it was evident that the actual invasion had commenced, and the enemy obtained a footing on our shores. When once complete units had been successfully landed in four different places, the troops from other points of at- tempted invasion were re-embarked and taken to these bases. The British Commander-in-Chief now decided on a plan of action. His forces being scattered and consisting mostly of untrained troops caused him to order a concentration on London, believing that to be the undoubted goal for which the enemy would make. The invaders could then knock their heads against our February, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 367 fortifications, while the army was properly organised for a great counter attack. On this account did the invaders receive but little opposition on their advance towards London, and within a few days they had formed up in positions opposite our southern line of forts. Englishmen were confident that their position would remain as it was until our forces were ready to assume the offensive, when the invading army would be driven back and the harbours on the south coast, now used as their bases of supply, re-taken. It was once thought that England could be starved out in a few days, but those who held such a belief proved to be greatly mis- taken. Not only were enormous supplies imported when it became evident that they would be required, but now every man, woman, and child cheerfully com- plied with the edict to go on quarter rations, and con- tented themselves with the meagre portion doled out, under ofiicial supervision, to all alike. In this way the country was able to hold out four times as long as had been anticipated. But a surprise was again awaiting the anxious Britishers. More Yankee notions were to prove their value. Dynamite guns and machine rifles wrought terrible havoc, but the most formidable innovation was the Subterranean Torpedo, capable of burrowing its way through the ground like a huge mechanical mole, and, at a given moment, raising a veritable volcano. Its progress underground was slow but very sure. The hydraulic drills which protruded from its head could bore into the hardest rock at a rate of 3 inches a minute, but this implied an advance of 120 yards a day. Within a week three of the principal forts had literally been blown into the air. The triumphant army then marched unhindered on London. It was a frightful blow to England, but the opposite feeling in the States exceeded all bounds. Yesterday it was England's great first line of defence, the sea, that had yielded to the attack, and to-day her downfall was completed by the breaking down of her land defences. Tumultuous exultation reigned everywhere. The President's last ovation could not be exceeded. Yet something must be done to celebrate this great occasion. The first vanquishing of a mighty power by the new nation, the conquest of an Empire of such huge pro- portions. America to rule the world ! England's navy vanquished would leave that of the United States far superior to that of any other nation. Canada would, of cour.se, be annexed to the States. Wild words are spoken on such occasions, and when it was suggested, half jokingly, that this mighty nation should be formed into an Empire, and the President chosen Emperor, the crv was vigorously taken up. Tush, wherever he went, was vociferously cheered and met with cries of " Emperor," " Founder of the Empire." Those who may have gained some idea of Tush's real nature can imagine how things struck him. The first time he heard the suggestion his mind was made up. Why should he hang back when others pushed him for- ward ? The result was — for he took good care to strike while the iron was hot — that within forty-eight hours the proclamation was issued that, by the unanimous consent of the citizens of the United States, Cornelius Jehoshaphat Tush was proclaimed Emperor of all the territories of North America ! 1 he people of the States were in boisterous jubilation. But tliey were soon to receive a sad blow. This was not the first time in history when public rejoicings have proved to be a little premature. When the news came that the invading army had not yet actually entered Lontkin, it was considered merely a politic dohiv, and that the forts subdued and the way clear, the formal entry would very shortly take place. It now transpired, however, that one more obstacle had to be surmounted before that could happen — the New Thames. The northern bank of this great waterway was now found to form one continuous fortification. Tier over tier of rifle trenches had been constructed with loophoied steel armour facing the masonry. There thousands of rifles could belch forth their hail of bullets with practical impunity. For the American bullets and even shells struck harmlessly against these solid ramparts, except they happened on one of the very small openings through which the defenders' deadly missiles were emitted. But the actual parapets formed so small a target that very few projectiles struck them. The land torpedoes could be of no use here. The pneumatic guns threw their projectiles across, but they were unable to destroy the lines of narrow trenches in the far banks manned by thousands of British volunteers. After a heavy bombardment with all their guns, of many hours duration, the Americans were not able to advance in force across the water. Boats were procured, but soon sank under the tremendous rifle fire brought to bear upon them. The bridges were already destroyed, and all attempts to repair them under fire proved too costly to be continued. Attempts were made to ford the great stream in the shallow parts, but obstacles had been put in the way, making this impossible. For two whole days the Yankees fought their hardest; hundreds of shells were sent into the far bank, but so well were the British entrenched that it was impossible to materially keep down their fire. Hundreds of the invaders were shot down in trying various methods of crossing, they being fully exposed to the British musketry fire. During the darkness of night boats full of men were pushed across, but it was found that there was a system of torpedoes laid near the far bank, and the only result was an appalling loss of life. Now for the first time did the public realise the reasons why the Government had insisted on the new river being made so wide. An endeavour was next made to outflank the position, but the far bank was found to be lined all along. Down stream the prospects of crossing over got more hopeless. Up stream the fight continued for many miles, but it soon became apparent that the passage of the big river, so well guarded, was a practical impossibility. For this dashing inva.sion, this raid in the enemy's country, no great store of supplies was a\ailable, and those already landed were nearly ex- hausted. The country through which they had marched had been cleared out of all food stuffs and supplies. For every available grain had been collected for the provisioning of the great city. About this time news filtered through that the great American submarine battleship had mysteriously disappeared, having, presumably, gone down with all hands. Now, too, the remnants of the British Navy had as.scmbled together at the Nore and Sheerness, and received such refitting as was possible. .\t the same time came the news that the ships in the Mediterranean, issuing under cover of darkness, had suddenly attached and driven back the United States squadrons set to guard that approach, others having gone round the Cape and attacked them in the rear. .So the tide had indeed turned. The main portion of the .American Fleet rapidly went south to endeavour to assist that part which was I)eing worsted off the coast of Spain. The remainder had to meet the unexpected attack of the desperate squadron from the Thames. The results were everywhere fatal for the .-Xmericans. 368 KNOWLEDGE & SCIENTIFIC NEWS. [February, igo6. The British Fleet chased and soon dispersed them near the Scilly Isles, and many being damaged and having no friendly harbour at hand to put in to, had to surrender, or else to try to make the great Atlantic trip in a disabled condition, in which but few were successful. Meanw hile the invading army, running short of sup- plies and finding itself deserted by its ships, had no alternative but that of surrender. Imagine the feelings of the newly made Emperor ! The intelligence of one crushing blow after another came to his ears. The first had made him perfectly sick with rage. The next came as a thunder-clap which fairly broke him down. The great strain of the last few weeks, the excitement of the elections, the whirl of events on being elected President, the arduous duties which followed, especially on the outbreak of war, had been all too much for him. But there was something more in store for him yet. It had been a matter of some surprise how small was the resistance offered by British troops to the landing in England, and the question was often asked, " W'here is the main British .Army?" It now transpired that the troops captured in the transports on their way to Canada, were but a very small portion of the army, which, supple- mented by a huge number of Canadian troops and volunteers, was now actually advancing from Canada southwards to invade the States. And all the flower of the .American army was in captivit)' in England. The Pacific, cleared of the enemy's ships, was alive with vessels bearing thousands of .Australians and Xew Zealanders bound to assist their fellow-colonists in Canada. This last shock was too much for the passionate monarch. The Emperor, on hearing it, fell unconscious into the arms of his private secretary. He was taken to his room, and medical men were promptly summoned. The gravest symptoms were manifest. Ministers and friends were urgently sent for. The Emperor's condition became more alarming. He rallied a little. His lips moved as if he wished to make a statement. At last his eyes opened, and with an effort he whispered " Libertia ! " She was kneeling at his side and holding his hand. Many of the principal ministers and friends of the great man were grouped around. " Libertia," he hoarsely whispered, " tell the pveople of England that they have misjudged me. Wrong I may have done — often — hut not such bad things as they accuse me of. That villain, Bateson, brought it all about. Would that I had been able to exonerate myself in their eyes. Tell them this." There was a long pause as all looked steadfastly on in solemn silence. At last he gave one heavy sigh, as of relief, and expired. CHAPTER XIII. Peace and Concord. .A few- days afterwards the following proclamation was eagerly read, not only through the United .States, but throughout the British Empire, and, indeed, by all the civilised world : — " Citizens of the United States, — I, your Empress by inheritance, crave your attention. " War, that awful heritage of mankind, bringing death and misery to millions, is raging wildly in our midst. War, whose only good is the suppression of the wrongdoers and weaklings of this earth, to demon- strate and maintain the survival of the fittest, is now- manifesting itself as a death struggle between the two mightiest nations of the globe. Between the mother and her child, fk'tween brothers of the Anglo-.Saxon race. Why should this continue? What real good can come of it? Does it not bring to both nations only sorrow and degradation ? " Then, I ask you, I beseech you, I command you, stop it ! It lies with you, the people, whose mind must be considered even by their sovereign. Think of it each one of you. Consider it in all its aspects. Shall we gain by the suppression of our neighbours ? What good would it do to each one of us personally to annex their territories, already so well ruled over, so judiciously managed? " Is it not a sin to continue such bloodshed, to sacrifice so many lives of noble, able, and accomplished men? " Then let us end this strife. Let us shake the hand of peace and settle down once more to carry on our com- merce, to bring happiness to our homes, to foster learn- ing and industry, to better mankind instead of butchering it. " I am, therefore, appealing for peace to that august ruler of the nation which we all should love, our kith and kin, that nation with whom we ought to go hand in hand to lead the civilised and uncivilised nations of the world and show them an example of how peace and freedom should be maintained. " Libertia." These soul-stirring words from the heart of the young and beautiful Empress made the greatest impression on all who read them. Both nations had suffeied greatly. Both had been humiliated, and but one opinion, strongly in favour of the proposed action, pre- vailed. In England it w'as the same. An armistice was promptly proclaimed, and within a short time a reasonable settlement arrived at, and a great Treaty confirmed, binding the two nations eternally to a close alliance for amicably ruling the world. One more scene in London and this short history is ended. It was a glorious day in June. That huge central street of London, the pride of Englishmen, the triumnh of housebuilding man, was ablaze with many-coloured bunting. Triumphal arches, flags, and banners, large mottoes of welcome, and coloured designs met the eye on every side. .All this betokened a nation's heartfelt welcome to a stranger — if stranger she could be called. Millions of English, old and young, had assembled to greet her, for the Empress Libertia had responded to the call of the British voices, and now arrived in their midst, a pure type of royal womanhood, the bearer of her dead father's last message. Xot forgetful of a day, many years ago, w-hen that lovely young form had knelt to Royalty, the Hope of England's future, the Prince whose destiny was mingled with that of the people, now looked upon this prepossessing maiden. Their hearts' strings were struck with a synchronous chord, and soon the nation learned with joy that in her he had sought and found his bride. The union of the Empress of .America with the heir to the British throne cemented even closer the unity, peace, and concord, so happily inaugurated be- tween the two mightv nations. 3^9 KDooiledge & SeieDtjfle flems A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. i6. [new series.] MARCH, 1906. SIXPENCE NET. CONTENTS see page VII. PKotogrsLphs of the CdLiials on Mocrs. Readers of " Kxowledge " are mostly aware of the discussions which have from time to time arisen as to the reality of the markings on the planet Mars of the nature of fine lines, and which some suppose to be canals. It has been suggested that these, instead of being distinct lines, are but the edges between grada- tions of half-tones (vide " Knowledge," November, 1903). Another theory is that they are the effect of a number of minor detached markings and not continu- ous lines. If, then, a photograph could be taken sulliciently distinct to make out these markings the question could be settled definitely. In May last the important announcement was made by Mr. Lowell that the " canals " had been actually photogr;iphed by Mr. Lampland at the Lowell Observa- tory, Flagstaff, Arizona. Persistent endeavours had for some time been made to secure such photographs, but great difficulties were encountered. Eventually a number of exposures were made on a continuous film with short exposures, similar to that of a cinemato- graph. On examination a number were found to show the canals, thus demonstrating indubitably the actual existence of the canals, or, rather, the fine lines on the surf;\ce. Mr. Lowell has now been good enough, at our re- quest, to send us some specimens of the actual photo^ graphs. TIk- reproduction whii-h we gi\e herewith may seem somewhat disappointing, but, as mav be Miii-li Kediiced p imagined, the extreme delicacv of the lines, which, though discernible under a careful examination of the original negatives, can hardly be reproduced in an ordinary photographic print, much less in a half-tone block. This little picture will, however, give some idea of the size and nature of the plate, and beside it are reproduced the careful drawings which Mr. Lowell has made from the original photograph. This view shows the Sinus Titanum region, and the following canals are visible in Mr. Lampland's photo- graph : — lu'ebus Gigas Helicon Laestrvgon Cerberus Pallene -Styx Boreas Kunostos Arion Ore us At the bottom of the right of the central point in the photograph a projecting nipple may be noticed. This was the first beginning of the new Polar Cap, and was then onlv thirtv-six hours old. The telescope used was a 24-inch refractor. The p'anet, at the time these photographs were taken, only presented a diameter of about 15 seconds of arc, and in order to secure the necessary definition only the central portion of the 24-inch object glass of the telescope was used, a diaphragm being interposed so as to give an eflfective diameter of 12 inches. A colour screen allow- ing only tlie orange and yellow rays to pass was also employed. The Lowell Observatory at FlagstaflT is situated at an elevation of 7250 feet above sea level, and in a particu- larly clear and dry atmosphere, so that the conditions are such as can hardly be obtained at any other observatory. luced- Reduced. May 20, loh. 42^-45111. IMiotoKraph liy C. O. Lampland May 22, loh. 20-30111. Drawings by Perciv.\l Lowell. X = Martian meridian central at the time. May 20, loh. 25-40™. 370 KNOWLEDGE & vSCIENTIFIC NEWS. [March, 1906. Coast Denudation in E^ngland. V>\ 1U>\VARD A. Martix, I'.Ci.S. Part II. As already pointed out, no part of the coast has suffered more greatly than where the cliffs consist of deposits of looselv-compacted sand and clav, and as scarc<_'ly any i^eolotvical formations other than of tertiary and quafernar}' ago arc found in ihis condition, hence it is where fhc.se deposits arc <'xpost'd to the sea-;\clion th.it the cr()sion is most felt. I'rohahly nowhere has denudation proceeded mori' ra])idly Ihan on the Holderncss coast of \'ork-shirc. N'arious estimates have been framed of the extent to which the coast suffers in this part, and the encroach- ment of the sea has been estimated at so high a figure as 30 feet, and liy others at so low a one as 6J feet, per annum. Probably an average rate would be found in that estimated by Mr. T. Sheppard, F.G.S., for the coast between Spurn Head and Bridlington, namely, 7 feet per annum. Between the.se two many ancient villages have disappeared — Wilsthorpe, Auburn, Hart- burn, Hyth, Cleton, Monkwell, &c. — and in some ca.ses the nruncs remain only as applied to modern spots which were formerly inland. Observations which have been made at Dimlington show that during the last few years the average yearly rate of erosion has been loi feet, and at Out Newton some ruins of an old chapel may he .seen which were, in 1833, 147 3'ards from the edge of the clifl. .South of Kiln.sea, where the low boulder-clay cliffs are about 10 feet in height, the cliff dies away altogether, and were it not for the protecting groynes which have been built by the Board of Trade, erosion here would probably be considerably greater than it now is. Mr. E. R. Matthews has made some interest- ing calculations as to the weight and extent of the area denuded. Many estimates have been made, and the.se will always differ to a very great extent, depending in the first place on the assumed rate of denudation, then the average taken for the height of the cliffs, and the average weight per cubic foot of the materials con- stituting the glacial beds of which the cliffs are formed. The estimated weight of the deposits removed has been placed at three millions of tons per annum, whilst Mr. Matthews places the area which has disappeared since 55 B.C., the date of the Roman invasion, at 115 square miles, or nearly the equivalent to that on which London and Greater London stands. Looking at it all from a geological point of view, one must bear in mind that the sea is only now encroaching upon what formerly belonged to it. The deposits which are now suffering are accumulations of boulder-clay and glacial moraines which had no existence in tertiary times, and up till the beginning of the glacial period the coast-line ran con- siderably further inland than that to which the .sea has even now attained. The .sea at that time approached closely the line of the eastern boundary of the chalk, which runs south-west from Flamborough Head in the direction of Driffield and Beverlcv. An interesting question which has puzzled ob.servers is. What has become of all the eroded material? The silting-up of the Humber is, to a large extent, due to its deposition, together with the growth of Spurn Head; and as it is denied by some authorities that any of the silt is carried forward to the Lincolnshire coast, it would .seem to follow that protective measures, if taken effectively along the whole of the Holderness cotist, would go a long way towards keeping a fair-way alwa3's open in the Humber Channel. Another portion of our eastern coast-line which is suffering at the present dav, and has, indeed, suffered • IS long as history can record, is that which extends Irom the northern coast of Norfolk along the .Suffolk and I'^sscx coasts to the Thames estuary. These, again, expose to the sea cliffs of but a partially-coherent material, affording little or no protection to the batter- ing-ram action of the waves. The deposits here formed are partly of glacial age, chalky boulder-clay being the principal material, and partly of Pliocene age (late Terliary), the latter being known as the " crag " forma- tion. In Essex the London Clay (Eocene Tertiary) has cropped out from iM'neath the crag, and this, although of a more coherent nature than the other deposits luen- tioned, affords but little more resistance to the crfiding power of the .sea. So when one leaves the chalk of the north of Norfolk we see, going southward, a gradual falling away in a south-westerly direction of the coast- line, and this only comes to an end when we reach the Thames, whilst on the south side of the estuary we find rai.sed as a bulwark against similar denudation the up- rise of the chalk. Tlie fault which occurs in the bed of the river, and which has let down the strata on the north side to a lower level than tho.se on the south, besides probably deciding the position of the em- bouchure of the river, has exposed the low-lying northern coast to the immediate action of marine de- nudation. Thus the whole East .-Xnglian coast is sub- ject to continual erosion. A map is preserved in the Yarmouth Town Hall, copied in the time of T'"lizabeth from an earlier one, which purports to show the coast hereabouts as it was in the year 1000. At that date the site of what is now Yarmouth appears to have been but a sandbank across the entrance to a wide estuary, extending up to Harles- ton and Norwich. Considerable concern is now felt lest, by the removal of the comparatively narrow line of cliffs, a similar state of affairs may ag'ain come into existence, and the low-lying land of East Anglia be- come permanently flooded. We have seen that Holderness has probably come into existence since the glacial period, and in these eastern counties again we see wide stretches of low- lands inter.sected by broads and sluggish streams, which show to the practised eye that the period is not far away back in geological time when the sea stretched away inland, covering those parts where subsequently the boulder-clay came to be deposited. The question of erosion is a burning one, but it must be borne in mind that a considerable area was wrested from the sea in those pre-historic times, when Britain's natives wit- nessed the passing away of the glacier mantle which had covered so much of the country. Although the coast of Essex has no doubt suffered much in the past, and the products of its denudation have been spread o\cr the sea-bottom in such a way as to shallow the sea for some considerable distance from the land, modern erosion is not now so .serious a matter as it must have formerly been, in view of the extensi\c mud flats over which the incoming tide pursues its way. But when one sees the evidences on all hands along the coast of the former existence of a much greater popula- tion than is now there to be found, there is good reason to think that many a flourishing \illage has been lost in the sea. The spreading out of the debris in the form of mud flats leads in the course of time to a contrary March, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 371 movement, with a possibility of reclamation, by the building- or raising of some kind of wall around areas covered at high tide. Such appears to have been done, for instance, around the mouth of the river Crouch. Apart from the steady planing down of the coast, there is in East Anglia the additional danger of inunda- tion. Some of the rich grazing grounds here are low- iving marshes, protected only by low cliffs. 'i"he recent fall of cliff at Pakefield, near Lowestoft, composed of boulder-clay, is but another instance of the gradual denudation of the cliffs, which, if not checked, must in the long run threaten the broadlands with inundation by the sea. There is every reason to think that before such a catastrophe could take place the protection of this portion of the coast would definitely be regarded as a national duty, and this might prove a first step to- wards the formation of a special Government depart- ment, having as its raison d'etre coast protection in general. In considering the disappearance of our cliffs we are not just now concerned with the loss of land in the pre-historic period, which was owing purely to a sub- siding movement of the whole country. Of such a widespread movement we have ample evidence in the numerous submerged forests, of which traces are ob- servable at abnormally low tides. That the subsidence was of a gradual and tranquil nature is shown by the very existence of such remains. The features of a land surface are apt to become effaced immediately the play of the waves commences to be felt upon it, and even under the most favourable conditions many of the trees would become w:ished out of the soil, whilst others would be broken off short, so that their stumps alone remained. But loss of land through subsidence of the crust is a thing against which seaside authorities and (iovernment departments might rage in vain. On the other hand, similar loss by erosion or denudation can be g uarded against, and this is what is now so eminently desirable. The Isle of Sheppey has been from time immemorial gradually slipping away into the sea, and the rich har\est of semi-tropical fossil fruits, turtles, &.C., from its London Clay clilfs iiave enriched many a museum. A few mik's farther east, on the North Kent coast, we see the wide stretch of flat meadow-land which extends in a south-easterly direction towards Richborough, mark- ing tlu silted-up bed of the water-way which formerly di\ided the Isle of Thanet from the mainland. But with the destruction of the tertiary cliffs at Reculver it is probable that the sea would already have commenced to reassert its right to the old channel were it not kept back by arlilicial embankments. The Sister Towers, which were, two centuries ago, at least a quarter of a mile inland, now stand at the edge of a .sea wall, reared by the Brethren of Trinity House. The Isle of Wight is, geologically considered, but an outlier of the mainland, but the oulv historical refer- ence to its lormer connection with 1-^ngland is contained in that much-quoted passage in .Strabo, alleging that carts laden with tin used to pass to the island at low tide, in order to ship that much-prized commodity off to I'ha'nician markets. If one takes one's stand upon the l)i>wns near to Tennyson's monument, and looks northward at low tide, one can easily conceive this to have been the case, seeing that in addition to the spit of land on which Iliust Castle is situated, numerous banks show themselves above low-water mark, and these are undoul)teilly the remains of a connecting link, which must have Ikh'ii apjiarent not many centuries .'igo. The broken condition of the coast between Alum Bay and Colwell Bay give evidence of great falls of cliff within modern times, and, indeed, geologically con- sidered, there is no doubt that onlv a short time ago the Solent was but a river which emptied itself into the English Channel some distance beyond the Needles. .\t this time the gradual erosion of Spithead, which was going on, had not accomplished its work, and a bay stretched out between Selsea Bill and Culver Cliff. It is not a little remarkable in this connection that off Selsea there is an anchorage which is even now known as the Park. Probably the scour of the up-Channel tides had a good deal to do with the erosion of the bay, and even now the same action is responsible for a phenomenon here, which is found only at one other place on the south coast, namely, the movement of the shingle from east to west instead of from west to east. To the same cause may probably be attributed the arrival in glacial times of the numerous boulders of granite and other rocks foreign to the neighbourhood, which have been seen at low water on the .Selsea coast. That erosion of the opposite coast on the island is still in progress is shown by the fall of tertiary cliffs which are frequently reported from Brading and the neigh- bouring east end of the island. Wherever the coast-line is made up of soft or incoherent materials, from those parts comes the strongest call for protection against the inroads of the sea. On the iron-bound coasts of the west the batter- ing-ram action of the sea has comparatively little effect. The submergence of Lyonesse, and the development of the hundred and fifty islands of which the Scillies con- sist, cannot positively be attributed to erosion any more than can the severing of St. Michael's Mount from the mainland. Possibly in both of these cases, as also in that of the development of the Bristol Channel, the pre- sent contour has been brought about by actual sub- sidence. But it is on the south and east coasts where land is lost. The Oligocene and Eocene of the Isle of Wight; the Thanet Sands of Peg well Bay; the Oldhaven Beds and Woolwich Beds of the Heme Bay coast; the London clay of Sheppey; the Red Crag (Pliocene) of Suffolk; the boulder-clay of East Anglia and of the Holderness district of Yorkshire; from all of these there comes the news of constant denudation, imd it is in respect to some of these that Government action will have first to be taken, if the matter ever comes to be regarded as one in which the State should interfere. New Radioactive Element. Mr. 0sk.\r K.min, in fractionating a mixture of bromides obtained from thorianite, found that whilst the radium accumulated in the least soluble fractions, the radio- activity of the most soluble portions also increased. A strongly active oxalate piecipitate of about 10 mg. was finally obtained, which glowed faintly in the dark and excited the platinocyanide and zinc sulphide screens in a marked fashion. If a current of air is blown through a solution of the substance and directed against a zinc sulphide screen, the illumination of the latter is some- what similar to that observed in a parallel experiment with emanium. It is shown, however, that the substance cannot be actinium or emanium. The emanation from the substance is almost identical with that of thorium, but the substance itstlf is fiom 100,000 to 200,000 times as active as thorium, and is supposed to contain a new- radioactive element. 372 KNOWLEDGE & SCIENTIFIC NEWS. [Makcii, 1906. The ColoroLtion of MacmmaLls ©Lnd Birds. By J. Lkwis Honhotk, M.A., F.L.S., F./.S , M.B.u.L ., Ac. (Continued from page 343.) W'c will now turn to the second part of this paper, which deals with the markings on mammals and birds, cur object being to show that throughout these groups certain si'OTS on the body will be found to differ in col- our from the neighbouring p.u^ts, although in many cases the differences will be either ;o slight or so transi- tory in their nature that they cannot be said to serve any of the purposes usually ascribed to the agency of natural selection. The conditions instrumental in bringing on a moult in mammals and birds are to my mind very obscure. A high temperature is undoubtedly a stimulating cause, as birds can be made to undergo a moult by merely keeping them in a warm atmosphere, but it is also necessary for a successful moult that the vigour of the animal should not be at t(K> low an ebb, though, on the other hand, it need not necessarily be very high. The state of its " vigour " at the time of moult is visible in the colour of the new coat, rather than in a suppres- sion or suspension of the moult. .'\nd birds in captivity in bad health will often show a tendency to become white. Nevertheless, it cannot be denied that moult is closely dependent on " vigour " ; for although the moult will not be omitted if an animal's vigour be very low, yet the attempt will [irove abortive and the animal will die. So that an animal cannot successfully moult without a certain amount of "vigour," but a moult will be attempted at certain fixed seasons, irrespective of that " vigour." Shortly before a moult takes place an alteration will be visible in the colour of many mammals and birds; this alteration is always in the same direction, namely, a lightening or, as it has been termed " bleaching " of the hairs or feathers, followed (and this is especi- ally noticeable in the latter) by a breaking up and com- plete disintegration of structure. I have referred to this matter in two previous papers,' but it may well be dealt with more fully. It has been generally assumed that this " bleaching " process is gradual, and due to the action of weather and light alone. This, as I hope to show^ below, is not so; the actual disintegration may lie brought about by the action of weather and light alone, but, if so, only after the hair or feather has been physiologically disconnected from the living tissues of the body. Tliis latter pro- cess generally, but not always, takes place when a new hair or feather is beginning to be formed, t One example of this is to be found in the so-called " white tail " assumed in summer by our English squirrel. Unlike the rest of its body, the tail is not * Ann. and Mag. Nat. Hist., 1900, Se.-. 7, Vol. 15, p. 492 Zoologist, 1901, p. 243. tThe leaves of deciduous trees ofler a similar, though not precisely analogous case. They turn yellow in Autumn as soon as the sap ceases to reach them and the coaling of bark tends to disconnect them from the trees. No one supposes the yellow and brown tints of Autumn to have been a gradual process going on throughout the summer, it does not ccmmence until the leaf is physiologically disconnected from the tree. Leaves on a broken bough undergo a totally different change. moulted in spring, but shortly after the spring moult the tail begins to turn to creamy white, beginning at the tip and gradually spreading towards the base. .Now, if this were merely due to the action of light, the " bleaching " would go on equally all over the tail, but this is not the case. Of this form of "bleaching," which usually pre- cedes a moult, I could instance numerous examples. In the case of the Anatidm, or ducks, in w hich group all the primaries are moulted at the same time, the bleaching of these takes place about a fortnight before they are cast, the whole process taking ten days, or at the most, a fortnight, and yet during the first eleven months of their existence the change in colour was hardly noticeable. This process of bleaching, however, need not always be caused by an approaching moult. I had a striking case some eighteen months ago exemplified by a Gad- wall, which began to bleach about a month after he had moulted. In the course of a fortnight his wings and most of his body feathers w-ere of a light dirty brown, and at the end of a month most of his feathers were entirely disintegrated and in shreds. 1 need hardly say that he was in very bad health. In the ordinary course of events these feathers would have lasted ten months practically unaltered, so that this disintegra- tion cannot be put down solely to external causes. At the follow ing moult the feathers were perfectly renewed. The so-called abrasion of the lips of hairs and feathers is another cognate case, for, although it is generally assumed that the tips gradually wear off during the winter, I can, as regards birds, positively state that this is not so. To take a single instance out of many that suggest themselves. In the reed bunting [E. scliocniclus) the black bases to the feathers of the head will be obscured by the brown tips through- out the whole winter down to the middle of March, and yet, during the three weeks from the middle of March to the end of the first week in April, those tips will suddenly be lost and the whole bird will become brighter, this change taking place without the pre- sence of a moult. Is it probable that these tips, which have w-ithstood the winter storms, should be washed away by April showers, imless there was some active physiological process behind it ? Many more instances could be quoted, but enough has been said to make it clear that " bleaching " only takes place when permitted to do so b\- physiological agency. In my former papers, quoted above, several groups of squirrels in which the " bleaching " is marked were referred to, and it was pointed out that it was quite absent in some species and present in varying degrees in others very closely allied and inhabiting practically the same country. Let us now carry the matter a step further and we will endeavour to show that bleaching is the origin of many of the markings and longitudinal stripes among mammals and birds. The oriental genus of squirrels, known as Haittfa, offers the best examples for a study of this question. The typical liatufa bicolor of the Malay Peninsula is a large squirrel, deep glossy black above and light yellowish below. The new coat when first assumed is always black, but " bleaching " soon sets in, although the extent to which it is carried varies grcativ among different individuals. In some cases the whole body becomes deep rufous bro\\n, the legs and feet remain- ing black, while the hairs of the tail show a few red March, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 373 tips.* Should it get still lighter, the hairs will be found to be annulated with pale red until finally one may get the hair of a dirty creamy white, showing no trace of colour whatever. This is pure " bleaching," possibly a thinning of the pigment, which may be with- drawn for the use of the body as has been stated to take place in the whitening of the Arctic haret. Let us now take a nearly allied species from the Natuna Islands off Borneo, R. bungm-ancnsis, and here we find the whole of the body of a brownish colour with rufous annulations, while the under parts are uniformly dark ferruginous, but almost immediately a new coat is assumed we find a patch on cither thigh bleaching, which process rapidly spreads until the whole body is light buff ; the under parts, however, not being affected to the same extent. On the mainland of Borneo we have another species, R. ephippium, noticeable for its purity of coloration, very few of the hairs having subterminal annulations. From the top of the head to the root of the tail runs a broad and very dark brown stripe, slightly lighter on the shoulders and spreading out over the posterior part of the body; the rest of the flanks, sides of the neck, face and ears, ferruginous, fading into pale orange on the limbs, feet, and throat, the colour being palest on the forehead. In R. bnramemis, a local form of the above, we find the colour practically the same but lighter. Thus, along the back, we find the majority of the hairs with light annulations, instead of being self-coloured, though self-coloured hairs are still to be found along the back and across the rump. The rufous colour has disappeared from the sides of the body except on the cheeks, and the limbs and feet are yellow. In R. af finis, a species from the south of the Malay Peninsula, the new coat is very light brown all over with still paler annulations, which almost immediately bleach to pale yellow. | We find, therefore, that we have in R. bicolor a species which in a new coat is pure black, but a species which, owing to bleaching, becomes very variable with light patches on various parts of its body, and, further, that other ncu'ly allied species will have their colour perman<'ntly differentiated in lines and patches situated in places simil.nr to those in which R. bicolor " bleaches. " Now, although in 7?. bicolor the amount of " bleach- ing " among various individuals may vary, yet the light-coloured patches will all start from certain definite "centres of bleaching," where "bleaching" will always first show itself, though it need not necessarily take place in all of them at the same time. These parts of the htniy, -a'hich are " centres of bleaching," I propose to call " poecilomeres. ' • .Although rattier beside tlie point it may malvs the matter clearer if I explain tliat in most animals the colours belong to one of two series, the actual sliade of colour depending on ihe amount and concentration of the pigment. The series are : — (a) White, clay, light brown, dark brown, black (zoomelaiun). (/>) White, yello>«[ orange, red (zooerythrin), and in a very concentrated form,' black. It will thus he noticed that black may be apparent from either of theseseries. This will, I think, lend to explain " erythrism," a common variation among squirrels where they tend to become red, and will account in this species for red tips appearing on the black hairs when they begin to lighten. It also affords an explanation as to why the allied species tend to be red and white in their general coloration, e.g. S, caroli rather than black and yel ow as in R. bicolor. t Barretl-Hamillott. Loc. cit.—-p. 307. ; For full descriptions of these species as well as of some to be mentioned hereafter see my papers in Ann. and Mag. Nat. Hist., ?er. 7, Vol. 5— p. 490 (igoo), and Ser. 7, Vol. 7, pp. 167, 160 (1901). The " poecilomeres," so far as R. bicolor is con- cerned, are situated as follows : — The shoidders and thighs. The crown of the head. The tip of the nose and lips. The tip of the tail. In true R. bicolor one may find all variations. Some- times the lightening process will start at the crown of the head and spread gradually over the back, becoming quite light across the shoulders and darker on the after part of the back, leaving the feet and legs black. .At other times, starting from the shoulders and thighs, the bleaching will spread down the legs, leaving the body black and the legs light, the reverse of the previ- ous case, or, sometimes, owing to the thigh poecilomcre spreading forwards, a narrow light line will be formed between the colour of the back and the under parts. In Scinrus rufonigcr, a Sumatran squirrel of the S. erythrccus group, we find this thigh bleaching rather more restricted and leaving a dark line of the colour of the upper parts between the " bleached " portion and the under parts. In this case we see, therefore, the beginnings of a dark as well as a light lateral line. Now suppose, instead of these changes taking place during the life of the animal, that they should have become fixed and that the animal is, in consequence, born with a so-to-speak " bleached " pelage. The hair will not, strictiv speaking, be " bleached," but it will differ in colour from the remainder of the body in the places where the poecilomeres should be. Scii/nis prcvostii arid Scitiriis caroli form very good examples among the squirrels, but the matter may be carried further than that; the white and black lateral stripes of the antelopes, the white lips of the same group, the white " blaze " of domestic horses and cattle, the white lips and feet of man}' ungulates, the starting point of the white back of skunks and ratels, the reddish thighs of some African jackals, white legs of the fox and polecat, light mu>;zles of many bears, light frontal patch of Bos frontalis; and among birds, to note but a few, the light patch above the beak of the white-fronted goose and the scaup duck, yellow on the crown of the goldcrest and manv tyrants, light wings of pheasants, &c. Examples might be multiplied for ever, but enough has, I think, been said to show that these " poecilo- meres " arc of sufficiently wide occurrence to render it practically certain that they are due to something more than mere coincidence, and I suggest that we see their earliest beginnings in the "bleaching" of Ralufa. As we examine more specimens it will be found that although some of these " poecilomeres " may be traced in almost all species th.it are not self-coloured, they will not always be lighter in colour than the rest of the body, but often, on the contrary, spots of more intense coloration, e.g., buttocks of many monkeys, shoulders of the panda, forehead of okapi, red " blaze " of the goldfinch, red on occiput of many woodpeckers, &c. We cannot give a thoroughly satisfactory explanation of this at present, but if it be once thoroughly estab- lished that (as Prof. Metchinikoff and Mr. Barcroft have proved for man, the dog, and the hare) colour may be, and is, extracted from the hair for the use of the body, it is only natural to suppose that any super- fluous colour (supposing the pigment to be of nutritive value to the body) would be stored up where it might most easily be got at, should the body require it. Much more information is, however, required before this can be positivjly stated. [To he continued.) 374 KNOWLEDGE & SCIENTIFIC NEWS. [March, 1906. TKe Aurora of November 15tK. By W. SiiACKi.KTOX, F.R.A.S. Ix \ io\\ of live wide-spread area over wliirli tlif aurora ol Xoxeniber 15 was observed, together willi the simul- taneous disturbance of the magnetic needle, it seems desirable to add to llie few particulars given on page 293 in the issue of December last. Observations of the aurora are recorded from Viirdo, Christi.inia, Szczawnica in Galicia (Karpathian Mts.), Wilhelms- haven (CJermany), many places in France, England, and Ireland, and also from Nova -Scotia; thus practically the whole of the northern parts of this hemisphere that were in darkness at the time of the occurrence have re- corded the phenomenon. Most observers agree that the aurora was at its maximum about g p.m. (Green- wich time), but Mr. Roberts, writing from Welshpool, states that he ob.served a fine display, with a maximum brilliancy about 6.10 p.m.; others also record this. In Nova -Scotia displays are recorded as taking place about 6 p.m. and also about 9 p.m. (Halifax time). From these observations it would appear that several displavs occurred on the same date. The earlier display is probably coincident with an easterly movement of the declination needle, but the one coinciding with the greatest disturbance is the display observed about 9 p.m., and curves from the magnetic observatories of Wilhelmshaven, Kew, and Stonyhurst, all exhibit precisely similar deflections. Through the kind per- mission of the Director of the National Phvsical Laboratory, Dr. Chree has supplied us with copies of the Declination and Horizontal Force curves taken at the Kew Observatory, and a similar declination curve is exhibited from Stonyhurst College through the kind- ne'is of Fathers .Sidgreaves and Cortie. DECLINATION loos Declination Curve, Kev It will be seen that aljout g p.m. a rapid easterlv movement of the needle began, reducing the declination some 33' in about 15 minutes, followed by an equally r.ipid return to the normal. Declination Curve, Stonyhurst, Nov. isth. The similarity of the curves is obvious, and Dr. Borgen, Director of the Magnetic Observatory, Wilhelmshaven, states that the large disturbance showed itself, in the same way, on the magnetic curves taken there. The disturbanc<'s of the declination needle w<'re ac- companied by a sympathetic' movement of the horizontal force magnet; the most prominent displacement, how- ever, coincides with the aurora observed in the early evening, when the horizontal force increased by 1057 in about 10 minutes, and then fell 1507 in the next 20 minutes (17= ,,;•"' C.G.S. unit). HORIZONTAL FORCE i^JS ' Two days' records are taken on eacli photographic sheet ; the upper is the earlier. The base line is the time scale. Horizontal Force Curve, Kew, Nov. isth. .\fter the disappearance of the aurora the needles continued to be disturbed, but not so \iolently, for about 30 hours. Of the many theories put forward in explan:ition of the origin of magnetic disturbances, one natiually associates these particular ones with the co-existing aurorae. The aurora of November 15 was particularly interest- ing on account of its vivid crimson tint, a type of aurora which is not common, the whitish yellow aurorae being more frequent. Observations from favourable localities like \'ardo, state that the aurora was by far the most splendid seen for many years. Strong aurorae of this kind are rare in England, and it is a matter of regret that so few spectroscopic observa- tions are forthcoming, especially as the origin of the auroral lines is not definitely known, in spite of the researches of Capron, Vogel, Huggins, Paulsen, and others. Usually, however, it is inconvenient to put aside a spectroscope suitable for this kind of work in the hope of an aurora coming along, and this may ac- count for the scarcity of observations; yet every ob- server who looks for aurora? should be provided with a spectroscope, for it is well known that the aurora line is visible spectroscopically when the naked eye fails to detect any display, and, again, many reputed aurorae would be shown to be mere sky reflections if spectro- scopic observations had been made. Both Professor Fowler and myself made independent spectroscopic observations, but neither of us were able to bring a spectroscope to bear upon the display whilst the crimson rays lasted, and no trace of a red line was seen, though special search was made. Ihi; common aurora line at X 5,572 was very strong, .iiid remained visible till midnight (as long as observa- tions were continued), whilst, in addition, three other laint and more refrangible lines were seen. The .spectrum of the aurora is most probablv a vari- able one, although the green line is persistent, but the phenomenon of gases exhibiting different spectra ac- cording to the nature of the electric discharge is conuuon, and it seems probable that the various tints of aurorae may be accounted for by the varying electric discharges through some gas in the upper reaches of our atmosphere. The nature of this gas has not been March, igo6 ] KNOWLEDGE & SCIENTIFIC NEWS. 375 definitely origined, though Krypton seems to hold out the most promise. Another theory ad\anced to explain the cause of aurorae is the pressure of light repelling some of the corpuscular matter surrounding the sun until it reaches the earth's atmosphere, the electronsbeing directed into the magnetic Meridian by the influence of the earth's magnetic field. Whate\cr he the cause and nnturf of the aurora, there appears little doubt tliat auroral displays are very frequently accompanied by magnetic disturbances, though the converse does not hold. CORRESPONDENCE. The Evolution of the Flower. To the Editors of "Knowledge & Scientific News." Sirs, — There are a few rather important oversights in Mr S. L. Bastin's paper on the above very interesting subject, which I venture to suggest might be mentioned, as well as a few additions made ; for since the paper is evidently intended for beginners in Botany, a few extra remarks might supply an additional interest to the subject. Comparing the use of flowers with vegetative methods of propagation, the latter is often much more important than the reader might, perhaps, suppose. Of course, annuals depend entirely upon seed ; but perennials often multiply for far longer periods than might be inferred from the expres- sion, " for a time at any rate." This may be enlarged to upwards of a century — c.i;., with Oxnlix CL-ynna, introduced into Malta from the Cape before 1S04; for it has spread, and is still doing so, by means of bulbs, along both north and south shores of the Mediterranean Sea, but never sets seed at all throughout that region. Our pilewort, too, rarely seeds. The object of Mr. Bastin's paper is to show that the four organs of a flower — the sepals, petals, stamens, and carpels — are fundamentally "homologous" with leaves; I'.i-., they might have grown out into true leaves had they not appeared as these organs. A little modification is here required; for it is rare to find the sepals, for instance, as representing a !.■/«)/,■ leaf or stalls and blade together. It usually corresponds with the stall< or " petiole " only, as may be readily seen in a rose. Very occasionally is a sepal the same thing as the blade, as in the corn-cockle. Similarly, petals usually correspond only to the " filament " of the stamens, so well described by Mr. Bastin in the Water- lily or in Canna; but in the l^anunculus family it is the " anther " of the stamen which is converted into the petal. The student should compare the " nectaries " of R. aiiricomus, R. F ii iiri It, a.ud other species, and he will soon discover /raiisi- tioiml forms, showing that while one half, the outer, of the anther grows into the broad yellow petal, the other, or inner half, remains arrested, like a tiny flap ; in the spot between the two, corresponding to the bottom of the anther-cells, honey is secreted. The little honey-pots of Hellebores and Winter Aconite are similarly constructed out of anthers. The " spurred " petals of the Columbine afford another good illustration; while in "double" Columbines the numerous " spurs " of the converted anthers fit into one another in radial rows. In the " green rose " and Alpine Strawberry every part of the flower is represented by a small green leaf; .some of them may still carry an anther-cell showing, as Mr. Bastin explains, their true homology. The first stage, therefore, was the conversion of leaves or " leaf-sc;des"into carpels and stamens. This stage is seen in the mull- flowers of Juniper and Cypress, though, unfortunately. we have no good case of a " Gymnospcrm " passing into an Angiosperm, the former having no indisputable representation of a " carpellary leaf" at all. The second stage was to construct petals out of stamens, as stated. In all the above plants mentioned the organs are "free," 'but "cohesion" often stepped in and united the parts of the " whorls " together. Mr. Bastin alludes to Cam- panulas in illustration, but here the five united petals make the bell, while the five sepals are external to it, and more or less joined together, but not to the petals to form the bell (which has only five free tips) as suggested by Mr. I^astin. Indeed, in a garden variety called the " Cup and .Saucer," it is the broad, flattened out blue calyx which makes the saucer, while the corolla is the cup within it. It sometimes happens that the sepals of flowers are white or coloured, as Mr. Bastin observes. Then they look tike petals, and are called "petaloid." Such is the case with several members of the Ranunculus family, as Clematis, Anemone, Callui, Aconitum, and Delphinium, but tliey must not be con- founded with petals. When such flowers become " double," it is not the sepals which multiply, but the petals, together with the stamens and carpels, which latter are now represented by petals, of which the whole number may be upwards of fifty, as in a stock, and many more in a garden Ranunculus. In Monocotyledons, such as tulips and hyacinths, the sepals and petals had belter not be described as " identical," except as to colour and form. Botanists regard them as being (;i"o distinct whorls, the outer and the inner, at least when the parts are not united as in a tulip, but they may be united as in the garden hyacinth. Nevertheless they should be regarded really as 3 + 3 rather than 6 in one whorl. Bracts, too, are rudimentary forms of leaves, being either homologous with petioles only, as in Hellebores (H. firtidus is an excellent illustration of a perfect transition in the reduction and loss of blade, with a diminution of the petiole into a bract) or of the blade only, as in Buttercups. Sometimes the bracts are brightly coloured and may puzzle beginners. But they are always outside the flowers, often includ- ing StivrK/y/mn-rs. as in Euphorbias and three in Boiigainvillea, a proof that they are not really parts of a flower. They not infrequently mimic a flower. Thus species of Cornus has four large white bracts, numerous minute flowers being within them. It thus looks like the flower of a Clematis, which may have four white sepals. A species of Euphorbia has fi\e rounded scarlet "glands," exactlj' imitating a five- petalled flower! It is only by a careful examination, which the beginner should always make, before the imitation is detected. All these coloured organs, as Mr. Bastin rightly observes, are to attract insects for pollenation. Nature sometimes .goes so far as to put all her energy, so to say, into the corolla, as to even sacrifice the stamens and pistils. Such is the case with the outermost flowers of a truss of Hydnin^^ea, which has only a coloured calyx, and the Guelder-rose, which has only a corolla. Such, too, is the case with the large trumpet-shaped " ray " florets on the head of a Centaurea. The outermost flowers of these plants have sacrificed their power of setting seed for the benefit of the commuuitv, consisting of incon- spicuous but fertile flowers in their midst. .•\s sepals, petals, stamens .and carpels will sometimes " revert " to be represented by true leaves, so may bracts. It is not uncommonly so with plantains. Ivach of the umuerous, minute flowers which form the dense spike, stand in the "axil" of an extremely minute bract. Sometimes, however, these bracts become "foliaceoiis " and grow out into small leaves. In the "Green Dahlia," the usually colourless bracts or scales, hidden among the flowers, become large, thick and green, all the florets being totally arrested. This change is expressed as the result of the " law of compensation," when one organ is enlarged at the expense of another ; but why these changes (ake place is a problem which cannot always be solved ; but the lesson we learn from .all this is, the wonderful power Nature possesses of constructing any organ she pleases out of any other. It is not only in flowers, but a .general capability, and is most admirably seen in such curious adaptations as the means of climbing and of catching and devouring animal prey, &c. George Hensi.ow. 376 KNOWLEDGE & SCIENTIFIC NEWS. [March, 1906. To the Editors of " Knowledge &• Scientific News." Sirs, -^ftcr roadint;- Professor Grorsje Ilenslow's letter, in vvhieh he taler acre (at present about 12.7 bushels per acre on the average) can be raised by use of fertilisers. Ot such fertilisers the chief is nitrate of soda, exported from the nitre beds in Chili. The demand for this has ri.sen from I, GOO, 000 tons in 1892 to 1,543,120 tons in 1905; and the supply will at the present rate I)e exhausted in less than fifty years. Then the only chance of averting starvation lies, as Crookes pointed out, through the laboratory. In 1781, Cavendish had observed that nitrogen, which exists in illimitable quantities in the air, can be cau.sed to enter into combination with oxygen, and later he showed that nitrous fumes could be produced by passing electric sparks through air. .Although this laboratory experiment had undoubtedly pointed the way, though the chemistry of the arc flame had been investigated in iSSo by Dcwar, and though Crookes and Lord Rayleigh 378 KNOWLEDGE & SCIENTIFIC NEWS. [March, 1906. had both employed electric discharges to cause nitrogen and oxygen to enter into combination, no commercial process had biH'n found practical for the synthesis of nitrates from the air, until recently. After referring, in passing, to the tentative processes of Bradley and Lo\ejoy, of Kovvalslvi, of Xaville, and to the cyanamide and cyanide prelre. Experiment had shown that it was equally good as a fertiliser with Chili saltpetre; and the lime in it was of special advantage for certain soils. The yield of product in these furnaces was most satisfactory, and the factory at Notodden — which had been in conmiercial operation since the spring of 1905 — was about to be enlarged; the neighbouring waterfall of Svaelgfos being now in course of utilisation would furnish 2-5, oco hor.se-power. The Norwegian company had further projects in hand for the utilisation of three other waterfalls, including the Rjukanfos, the most con- siderable fall in Telemarken, which would yield over 200,000 horse-power, .■\ccording to the statement of Professor Otto Witt, the yield of the Birkeland-Eyde furnaces was over 500 kilogrammes of nitric acid per year for every kilowatt of power. The conditions in Norway were exceptionally good for the furnishing of power at exceedingly low rates. Hence the new pro- duct could compete with Chili saltpetre on the market, and would become every year more valuable as the de- mand for nitrates increased, and the natural supplies became exhausted. What is at the Centre of the^arth? By H. DE .St. I^ai.mas. The mystery of this c|Ucstion is assigned as one reason for its investigation. It is, indeed, remarkable that less should be known about the earth's composition, even at the depth of a few niile3, than is known of the composition of stars millions of miles awav. In " Know i,ed(;e " for January doubt is cast on the generally accepted theory of .1 regular and sustained increase of heat as the earth's crust is penetrated. The data are not sufficient to establish this theory. The in- crease of heat in deep mines and borings has been attributed to the central heat of a gradually cooling planet. How can we know that this is the true cause of the heat at only a mile or two from the earth's sur- face, seeing there is no proof that the fiery heat extends to the earth's centre? Reasoning on the effects of pressure at various depths, Mr. lieresford Ingram suggests that the earth may consist of " three concentric rings," having a solid nucleus from 3,000 to 7,000 miles in diameter, next a liquid substratum, and finally the earth's crust, variously estimated at from 70 miles to 2,000 miles in thickness. Dr. I-xlmund Halley propounded a similar theory of the earth's composition before the Roval Society in 1694. The mysteries of terrestrial magnetism seemed to point to such an arrangement to account for the uniform slow revolution of the magnetic fxile round the pole of the earth. The nucleus (or TcrrcUa) imagined Ijy Halley, though concentric with the main body of the earth, he maintained rotated on a different axis, the axis of the nucleus being indicated by the magnetic poles. Halley considered that the axis of the nucleus was originally that of the entire earth, and that a change of axis had taken place in relation to the outer globe, this being the physical cause of the deluge, as it would necessarilv bring the ocean waters and .Arctic ice over mountains and continents. Halley maintained this belief more than thirty years till his death. The late Sir Edward .Sal)ine, speaking Irom the Presidential chair of the Royal .Society in 1864, said that " the objections that might ha\e im- peded the reception of such an hypothesis . . are no longer tenable." 1 he late astronomer royal, Sir George Airy, expressed the opinion " that the general cause of the earth's magnetism still remains one of the mysteries of cosmi- cal physics." The distinguished Lord Kelvin has ex- pressed himself similarly only a few years ago. So that we are now no further advanced in actual know- ledge of the earth's interior and of terrestrial magnetism, than when Halley maintained more than 2oa years .igo that " thus and not otherwise " could the facts be explained. Halley 's fhetjry of the earth has been popularised by the late Rev. W. B. Galloway, M..\., in " Science and (ieology in Relation to the Universal Deluge" and "The Testimony of -Science to the Deluge." Mr. Galloway shows that the specific gravity of the earth being about 57V times that of water, whilst the rocks at the earth's surface do not average more than ai, it follows that the heaviest substances, such as gold and platinum, should be at the centre, and that mercury or C|uicksilver, in harmony with its specific gra\ ity, might form the liquid substratum between the two differently rotating globes. The arguments — astronomical, geo- logical, climatic, and historic — in support of Halley's and Galloway's theory of the earth are well worthy of examination. Whilst astronomers and geologists cannot tell if the earth has a rigid core or a molten interior, the hypothesis of " three concentric rings " should not be regarded as untenable, i.e., an inner and an outer globe with a fluid substratum, such as mercury, petroleum, or molten la\ a (all of which have Ix'en suggested) inter- posed between the TcrrcUa and the outer globe. In such case the heat, which is found to increase in de- scending below the earth's surface, might be caused by the friction of two differently rotating bodies, and not bv imaginary fires at the centre of the earth March, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 379 Rare Living Animals in London. By ]'. L. ScLATER, Dr.Sc, F.R.S. VI.— Forster's Lung- Fish {Ceratodus forsttvi). A "queer ush " i;i a proA ciliial expression, and is certainly very applicable to- the fish now figured from one of two specimens received by the Zoolog-ical Society in 1898, and still living- in one of the large tanks in the reptile house. For many years there had been know-n from the Triassic strata of various parts of Europe, certain fos- of them in the " Proceedings " of the Zoological Society, under the name Ceratodus fcrsieri (see 1^. Z. S., 1870, p. 221). He referred them, no doubt correctly, to the genus Ceratodus, by which name Agassiz had designated similar teeth in his " Recherches sur les Poissons I^ossiles." The Barramondi is, in these days, found in a state of nature, only in two little rivers of Queensland, the " Burnett " and the " Mary," though its fossil remains prove that it formerly extended over a far larger por- tion of Australia. 'Phe best account of its life and habits will be found in Dr. Richard Semon's most in- teresting work " Itn .\ustralischen Busch," of which an Eng-lish translation was published in London in Forster's Lung- Fish {C<'nitoHC (.Or. Henry Wood- ward, F.R.S., and Dr. H. B. Woodward, F.R.S.) held a reception on Tharsdav, February 8, to conimciiioiale the publication of the 5oolh number of the magazine. The rooms at No. 5, Johnson Street, Notling Hill Gate, W., were well filled, and many ladies and distinguished men of science gladly responded to the invitation. Excellent music, vocal and instrumental, was provided, and geological photo- graphs and drawings were exhibited. We trust the Gtohnii- cal Magazine may long continue its most useful work. 382 KNOWLEDGE & SCIENTIFIC NEWS. [March, 1906. The Eolithic Controversy. By J. RussHi-L Larkby. TllF. recent renewal of the controversy i>ii the nature of Koliths (Man: Anthropological Inst., Oct., Nov., and Dec, 1905) has had the result of awakening further interest in the question of the authenticity of these forms as illustrating a pre-Pala?olithic period of man's progress. As siiggested in my note in " Knowledge " for October, 1905, p. 252, it is necessary for the objec- tors t(j the artificial origin of these forms to show that the mechanical process of Mantes in ;my way resembles the natural method by which the plateau or any other gravels were laid down. On December 19, 1905, Mr. S. Hazzledine Warren, F.G.S., read before the Anthropological Institute a paper on this question, in which he attempted to show the purely natural origin of these forms. In illustration of his contention Mr. Warren made several pseudo- Eoliths, which were handed round for the inspection of his audience. The mechanical process in this case took the form of a screw press, in the lower jaw of which was a small circular pit; two stones were placed in this receptacle, and on pressure being applied, the flints were fractured in a way which certainly, to some extent, resembled Eolithic impleinents. Whilst con- gratulating Mr. Warren on the ingenuity thus displayed in support of his contention, it is impossible to give assent or support to his deductions. I should characterise this process as an artificial method of the most pronounced type ; it rests with its originator to prove that any legitimate comparison can be drawn between the screw press and natural deposition. Mr. Warren eliminated two most important factors in his experiment; in the first place, the presence of water under natural conditions must very materially reduce the intensity of any blows received by the stones when undergoing free rolling in a river bed; secondly, the hard, rigid bed of the screw press has no similarity to the soft and muddy floor of a river channel, hence the blows received by flints in the process of rolling would again undergo a considerable diminution. I would again emphasize the fact that in the plateau gravels there are forms which are not only definitely chipped, but are almost wholly unabraded by transport; others, however, show- the work obscured by subsequerit roll- ing, and to some of these highly-worn examples excep- tion might well be taken if they were not accompanied by the unworn forms. It may, however, be objected that the \ery presence of the chipped edges is indicative of natural action, and this obviates the necessity of suppos- ing man's presence here during the deposition of this drift. To this it may be answered that those flints with slightly abraded edges bear very few insijjient cones of per- cussion on their flatter surfaces; therefore, if the chipping is purely natural, the process of rolling was confined entirely to certain areas of the stones. This hypothesis will not commend it.self to students of the question save as a rcdiiclw ad absurdum of the natural origin theory, and yet it is the conclusion to which our opponents are forced if they persist in at- tributing these forms to some agent other than an in- telligent being. Mr. Warren's contention seems to be that as the results of certain mechanical methods of the present day closely simulate man's work in the past, Ipso facto, man has ne\er produced them at all; but to produce such forms by an essentially artificial method, and then to assert that in the past they could only be the outcome of natural action seems to me to 1)C illogical. Mr. Warren's answer to the claim that Eoliths are shaped according to definite types, is that the shape is governed by the existence of lines of weak- ness; therefore, the matter of definite type is simply the natural result and proof of such lines of weakness. The argument is pleasantly attractive from a purely theoretical point of \iew, but it is essentially a case of assertion arising from assumption. It is necessary to prove the existence of these lines of weakness where thev would be least expected, i.e., the thickest parts of the flints, for some Eoliths in my collection are as well chipped at the base as at the thin edge. To the " creep " of frozen and partially frozen soils and gravels Mr. W^arrcn w'ould assign some types of Eoliths; but here, again, is very debatable ground. My own observations in the area of the Daren t and Cray lead me to believe that in this instance very little post- deposition movement has taken place; as the only site at which there is clear evidence of frozen conditions is a small plateau carrying a high level Darent gravel, the " creep " must have been of an insignificant nature — hopelessly insufticient, it may be suggested, to shape and chip the definitely-formed and striated Eoliths found there. To those who have devoted their time to practi- cal investigation in the field and to careful classification at home, it may seem inconceivable that the definite and classifiable types of plateau flints are merely the result of fortuitous batterings; save on the theorv of intelligent design, it is difficult to believe that certain forms would be repeated over and over again and at- tained by a remarkable similarity in the type of work and the angle of chipping. All students of this interesting question are indebted to Mr. Warren for his careful paper, and if it fails to obtain the elimination of Eoliths from the field of science, it will at least show the crying need for greater care in the admission of indefinite evidence in support of our claim. There can be little doubt that even in England flints have been admitted as evidence which should have been left in the field or consigned to the heap of rejected forms in the garden. \\'hen, how- ever, it is said that in the gravels of St. Frest 80 per cent, of the flints are considered as either " utilised or retouched,"* it is impossible to refrain from raising the cry of " Siste, viator." To Make Iron Grow. To the Editors of " Knowledge & Scientific News." SiRs,^In your January number, page 330, you have a short notice under the above headin.Lj, slunving that iron by repeated heating to a critical teni])erature ,ind coolino minutes past 5. A sm.-iU star w;is close 1,, the moon an:inal. The diflicuhics of working out such a method are such that they might well be regarded as insurmountable. The three dyes must not only be of the correct tints, but they must be fugitive enough to be bleached by an exposure to light of a reasonable duration, and, after the print is made, they must be permanent enough to be but little affected by ordinary light. It is sought to secure these opposing qualities bv adding materials that induce a temporary sensitive- ness, and removng them when the print is made. Jan Szczepanik has overcome these difficulties so far that the firm of J. H. Smith and Co., of Zurich, are preparing to issue the .sensitive material commercially. .\t the exhibition of colour photographs arranged by the editors of the BriUsh Journal of Photography at their offices, and which is just about to close, there are a few very striking examples of this process, copies of " lithophanes," that is, the coloured material some- times used for window decoration. The colours in the copies are very clean and bright. Of course, the large flat patches of crude bright colours in the originals are not so .severe a test as more delicate neutral tints, and as the originals are not exhibited it is impossible to tell whether the colours of it are fairly matched in the copies, but it is quite evident that bold colours of very various kinds have been obtained. Mr. Cobttrn's Work. — There is an exhibition of the " Work of .\lvin Langdon Coburn " at the house of the Royal Photographic .Society in I'iussell Square, to which anvone is welcome, until the end of March, on presentation of his card. The exhibits are advisedly not called photographs, for we learn from Mr. Bernard Shaw in his preface to the catalogue that Mr. Coburn is very mixed in his methods, making gum prints, for example, on the top of platinum prints. When Mr. Shaw tells us that Mr. Coburn has " condescended to oil painting as a subsidiary study," we are led to ex- pect excellent work in spite of Mr. Coburn 's lack of experience, for he is a young man of only three-and- twenty. The series of some forty portraits is distinctly interesting. They are done in an unconventional style, and although a few of them appear to show- a desire to h^ eccentric, some of them are very fine indeed, and well repay the trouble of a visit to see them. Of the eighty other specimens, Mr. Bernard Shaw appears to consider it necessary to make a sort of apology, for he tells us that Mr. Coburn 's " impulse is always to con- vey a mood, and not to convey local information," but the author himself entitles the most of them by the names of places, streets, bridges, and so on. For my part I cannot imagine them " conveying moods " of a pleasant or satisfactory kind to anyone; their detail- less flat patches, extreme want of definition, and the absence of a sense of due proportion, are distinctly un- pleasing, and the representations of places that I know are useless as reminders. If these pictures were not put forward as serious work — and I suppose that they are meant to be taken seriously — I should have thought that they were a beginner's attempts, with here and there a promise of better things in the future if the maker of them considered it worth while to persevere. It is difficult to l>elieve that these " works " and the portraits in the other room are by the same author. Received. — The Thornton-Pickard Catalogue for 1906 is to hand, and besides the well-known speciali- ties of the firm, it includes a new pattern of the " Royal " shutter, that is, the roller-blind shutter with the mechanism inside the case, and a low-priced outfit called the " Imperial Perfecta. " REVIEWS OF BOOKS. Our Stellar Uoiverse. Stereoscopic Star-Charts and Spectroscopic Key Maps. Thomas Edward Heath. (King, Sell and (Jlding, Ltd.). (26-i-vi. with 26 plate.s and 26 stereograms.! los. net. — Changing his view-point, Mr. Heath, instead of imagining him- self at a distance of many light-years from the Solar system, now endeavours to give a ^-dimension idea of the relative distribution of stars as seen from the earth, replacing the celestial sphere for this purpose by 26 regions, which for the purpose of the key maps are represented by tangent planes, one at each pole, eight round the equator, and eight each at latitude 45^ north and south respectively. The corresponding stereograms by the introduction of measured discs, and an allowance for parallax 19,000 times greater than the truth, do represent a system hanging in three dimensions, and the effect is certainly much improved by the piercing of the stereograms to give the stellar appearance not evident on the prints, h special set on thick card is issued at 5s. (or 2s. 6d. to purchasers of the booki. Authorities are given for the values used for parallax of the better determined stars ; for others an average parallax according to spectrum-type is used, which, although it improves the appearance of the stereograms by admitting a larger number of stars, is open to criticism on account of the arbitrary assumption involved. This, however, is of no great consequence, as the scientific value of the stereograms is of much less importance than their popular interest. The spectroscopic key maps give full details as to the name, magnitude, spectrum-type, and parallax of the principal stars, and are meant to enable the purchaser to identify the objects represented in the stereograms, which look far less familiar than the actual stars in the sky. It is unfortunate that the endeavour to cultivate a sense of propor- tion, which is so often lacking nowadays, should be compelled to start with an exaggeration of such a magnitude as i to ig.ooo. Bat the fault is not with the author, whose device is to be commended for its boldness. It is possible that we shall see this principle of exaggeration carried even further, on the ground that the relative proportions are strictly preserved as under a high-power microscope, but the work of Mr. Heath goes as far as appears ad\ isable in that direction. It should be remembered that magnifying the parallax ig.ooo times does not mean observing with eyes 19,000 times the normal distance apart, but with eyes whoss distance apart is 19,000 times the diameter of the earth's orbit, or about 34^ billions of miles. The Reconstruction of Belief, by W. H. Mallock (Chapman and Hall), price 12s. net. This great work, by the author of "Is Life Worth Living," is somewhat disappointing. The enquirer after religious truth, the agnostic requiring enlightenment, the Catholic anxious for confirmation of his early teachings, all are likely to close the book with the feeling that they are not much the wiser than when they opened it. Vet it is all good reading and sensibly written, and if, after a study of it, we are not convinced as to the exact standing and meaning of modern religion, at all events our minds may be opened and our thoughts concentrated on many points well worth considering. The author points out that at the root of Christianity are three doctrines, namely, that the universe is over-ruled by some supreme intelligence, who has for his special object the highest good of man ; that each man is a self-directing personalitv, answerable as such to the supreme intelligence for his conduct ; and that his life here derives an infinite importance from the fact that it will be prolonged and com- pleted for better or for worse hereafter. He then adds that even those who are satisfied to let these doctrines go, are conscious of some sort of loss, and desire to find a substitute for them ; whilst others are lookinsj about for some means of defendinsr them, which mav justify them in retaining their faith. It is to this latter class that the present volume is ad- dressed, and thousrh they may derive some comfort and extract many useful ideas", we think it cannot be said that all doubts such as linger in many minds to-day will be eradicated. March, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 385 The Religion of Woman, by Joseph McCabe, issued by the Rationalist Press Association (Watts and Co. ; price 6d.). — This curious work, prefaced by some stirring remarks of Lady Florence Dixie, seems to infer that woman owes her present position of bondage and slavery to man entirely to " Supersti- tious Religion," that is, the word of the Bible. As soon as she chooses to give up a belief in this, she will be ready to throw off the yoke c f masculine oppression. It is interesting to trace the position of woman in the various periods of history, and this is well detailed in the book. Philip's Large Planisphere (G. Philip and Son, 6s. net). — Designed by H. Gcwecke (and made in Germany). A large planisphere, [his is i ft. 8 in. diameter, is useful, as showing more clearly the positions of the smaller stars, and the adjust- ment can be more accurate than with the more usual small size. But in this case, although '• an attempt has been made to pre- sent a picture as closely as possible resembling the sky " it is in this respect not wholly satisfactory. Fourth magnitude stars are represented by small circles, which is decidedly con- fusing at first. While some of the constellations are indicated by allegorical figures in an inconspicuous grey, others such as (iemini, Aries, and .Auriga are not thus depicted. In order to avoid encumbering the map.no lines of R. A. or declination are given, but positions are readily found by a graduated straight- edge, which can be adjusted to any point of R. A. marked on the circumference, while the declination is marked on this straight-edge. This large planisphere will undoubtedly be found a most useful addition to the amateur's observatory. — " K." Historical and Modern Atlas of the British Empire, by C. Grant Robertson, M..\., and J. G. Bartholomew, F.R.SE., F.R.G.S. (Methueni ; price 4s. (xl. not. — This is a most useful and handy little atlas, specially prepared for students, but also likely to be of value to all those who wish to learn more of the great Empire to which they belong (or do not belong). The first few pages are devoted to a short but concise account of the British Empire, including an alphabetical gazetteer, tables of statistics, and index to names. Then follows a series of most interesting and well e.xecuted maps descriptive of the growth of the Empire at various periods in history. Maps of the world showing natural features, density of population, commercial development, &c., are given. Then a num- ber of maps of England, Scotland, and Ireland, to show vegetation, coal and iron, industries, population, phvsical features, and political divisions. Numerous maps of India, Canada, South Africa, and Australia follow, and the atlas ends up with a table of the " Chronology and Expansion of the British Empire." Divine Dual Government. ;\ Key to the Bible, to Evolution, and to Life's Enigmas, by William Woods Smyth (Horace Marshall) ; price 6s. — The subjects which this book professes to cover are so appalling in their magnitude and " unknow- ableness," that we hesitate before lightly casting it aside with a few commonplace remarks. The author commences with a preface in which he explains that his own interpretation of the works of Darwin and Herbert Spencer are so dilferent from the interpretation of them by other writers that he has " always attributed them to the direct teaching of the Spirit of God." (ilimpses are t.iken of early history and the dawn of revela- tion. There is much that is of interest in comparing the words of the Bible with scientific theories. Some may think the per- version of Biblical words and phrases may be carried too far. Thus the word " day " in Genesis, with reference to the Creation, is often supposed to imply a very dilferent period of time to that which we know as day. The author supposes it to mean 10 million years. But he clearly shows how diflicult it is to arrive at any certainty when speaking of any such vast period. We can recommend anyone who wishes to investigate such subjects to study this book, although we would not say that personally we are at all satisfied with many of the conclusions arrived at. The same author sends us a little pamphlet on " the Cost of Man's Creation and Redemption in the light of Natural Science," which is of much the same nature as the book. The Theory of Experimental Electricity. (Cambridge University Press.) W. C. 1). Whctham, F.R.S. ; 8s. net. This text-book represents a course of class lectures delivered at Trinity College, Cambridge, and is intended to be a book of reference to which "tudents may turn for further elucidation of points cot clear to them. It is no mere cutand-dried account of classical electricity, but aims at giving also " some insight into methods of research together with some idea of recent results, and of unsolved problems ripe for examination." The subject is thus presented as a living one. and this tends a great deal towards the making cf a most interesting volume. But on the other hand the historical side is not neglected; in the case of the introduction of any fresh fundamental fact or principle, a brief but clear account is presented of the par- ticular mode in which the fact was first learned. The chapters which will probably be turned to first by the reader who has already mastered the rudiments of the subject are those on conduction in gases and on radioactivity. So much of the new work on these questions has been done by the Cambridge School that we naturally look to it for a satisfactory exposi- tion of it, and we are not disappomted. Further, the text is exceedingly well printed and the diagrams are wonderfully clear. The Scientific Roll and Magazine of Systematized Notes. Bacteria. Conducted by Alexander Ramsay. Published by R. L. Sharland, 38, Churchfield Road, .•\ctoD, W. ; is. — This quarterly magazine has now ceased to be a mere recording roll of classified Bacteria. Useful, as it no doubt was, to a limited number of students, it may now claim a widerinterest by reason of its containing readable matter. The conductor, wisely we think, promises in future numbers to introduce bacterial studies bearing on the problems of Health and .-Vgricultural Economy. A more than something is known of the Bacterial Causation of Human disease, and our knowledge is rapidly extending. The same cannot be said of the Bacteria of the Soil; agricul- turists know nothing of the bacterial invasions leading to the birth, growth, and decay of crops, iS;c., or of those producing disease in the same. Mr. Ramsay promises to enlighten us in this work on these problems, among others, and so benefit scientists in particular and mankind in general. This is the fourth year of the '• Roll's "existence. Under its new develop- ment it promises to have an e.xtended and successful future. S. G. M. An Introduction to the Infinitesimal Calculus. Dr. H. S. Carslaw (Longmans; 5s. net). — This book is written specially for ist-year science and engineering students by the Professor of Mathematics in the University of Sydney. The object has been to present the fundamental ideas of the Calculus in a simple manner, and to illustrate them by practical examples. It will prove a very useful little book for use. especially in technical schools, .•\lthough rigorous proofs are as a rule avoided, there is little in the book which anyone would need to unlearn on going on to a higher stage. We commend it also to anyone who wishes to teach himself the elements of the Calculus as being very clear and likely to help him over the difficulties which beset the private student in his initial attempts to tackle this somewhat formidable but fascinating and important subject. Leather for Libraries, by E. Wyndham Hulme, J. Gordon Parker, .'V. Seymour Jones, Cyril Davenport and F. J. William.son. Published for the Sound Leather Committee of the Library Association (Library Supply Co.) ; is. 6d. net. This is an important little work, since every book-lover wishes to know what is the best material with which to bind h's volumes, and many, sorrowfully noting an unexplained de- terioration in their bindings, are most anxious to know the cause and remedy. Here is a practical and unbiassed account dealing with the technics of leather, and clearlv set- ting forth the causes of decay, the methods of preparation, and the most suitable kinds of leather for bookbinding. Machine Construction and Drawing, by Frank Castle (Mac- inillan) 4s. 6d. — This is a useful guide to students and others to learn the practical details of machinery with the object of making working drawings. Such details as rivets, bolts and nuts, shafting, belt pulleys, bearings, pipe joints, and parts of engines are fully described with specimen drawings. W.' have received a new catalogue of telescopes, iKc by Messrs. R. and J. Beck. This includes many instruments suitable for the amateur astronomer, especially 3-inch tele- scopes, and various stands and mountings. There are also astronomical cameras, microscopes for star photographs, dilTraction gratings, theodolites, and other instruments. 386 KNOWLEDGE & SCIENTIFIC NEWS. [March, 1906. ASTRONOMICAL. By Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S. Recent Work on Sunspot Spectra. Two importaut papers dealing with the special features of the sunspot spectrum have recently been published. W. M. Mitchell, observing at the Princeton Observatory (which has been rendered notable by the work of Professor C. A. Young on the solar chromosphere and spots), has given a long list of specially aflected lines, an analysis of which confirms the interesting results of previous observers that most of the chief lines concerned are due to the rare elements vanadium, titanium, and some unknown elements. Many of the chief lines were observed as reversed, giving bright centres to the lines. G. E. Hale furnishes a long list of lines observed in the spectra of spots photographed with the magnificent equipment lately installed at the Solar Observatory on Mount Wilson in California by the Carnegie Institution. The beautiful illus- trations accompanying the paper will convince many who may still have lingering doubts as to the reality of these specialised phenomena of the sunspot spectrum. In the analysis of the lines observed, the lines chiefly affected are ascribed to titanium; then come lines of manganese, chromium, calcium, iron, nickel, and cobalt. It is specially noticed that all of the lines of silicon in the region examined are much weakened. Many of the •' sput band " lines have been photographed and are identified with faint lines in the Fraunshoferic spectrum. Va.riation of the Figure of the Sun. From a further examination of solar measurements made b\- Schur and Ambronn with the heliometer at Gottingen dur- ing the period iSgo-igo2, C. L. Poor has obtained more evidence in confirmation of the reality of the variations of the sun's figure which he put forward a short time ago. These later measures cover a whole sunspot period of 11 years, and they show a decided periodicity, the polar diameter being larger in 1S90-1, while the equatorial diameter was greatest durmg 1S92, 1S93, and 1894. The e.xact length of the period is uncertain, but it appears to be nearly the same as the sun- spot period. The amplitude of the variation is about o"'2 ; the difference between the largest positive and negative values being about o"'5. These heliometer measures thus corroborate the conclusions previously determined from Rutherford's photographs, but the amplitude of the variation is much less in the case of the visual observations. Ne>v Astrographic Refrak.ctor for Cincinnati Observatory. We hear that the Cincinnati Observatory has recently placed an order with Messrs. T. Cooke and Sons, of York, for one of their triple ptiotovisual astrophotographic objectives. The aperture of the new lens will be 9'5 inches, and its local length 677 inches, so that one millimetre on the photographic plate will be equivalent to two minutes of arc, this scale being half that of the International Astrographic series of negatives. It will be noticed that the ratio of aperture to focal length, or intensity, of the new lens is 1:7, much greater than the usual ratio of i : iS. Moreover it is confidently stated that the objective will give good definition over a field fully 15° in diameter, and so should prove specially satisfactory for photo- graphing comets, nebula, and asteroids. This new photo- graphic equipment will be attached to the tube of the old 1 1 -inch refractor, at present mounted in the Mitchell Memorial Building. Annular Nebula in Cygnus. M. G. Tikhoff has recently communicated to the Comptes Ktiidtis an account of a scries of photographs of nebulae he has obtained at the Meudon Observatory. Some of these show very interesting details of the .Annular Nebula in Cygnuy, N.G.C. 6894. They were taken with a telescope of one metre aperture and three metres focal length, with exposures from 2 ' 20'" to j'', on September 27 and October 27, 1900, respec- tively. The nebula is in the form of an elliptical ring with a central condensation. The major axis is about 44"'8, and the minor axis 37"j, It is composed of two rings, an exterior broad one and an inner portion somewhat thinner. On the north-west portion the doubling is interrupted by the presence of the star discovered by Lord Kosse in 1S55. On the outer ring there are several condensations, of which the two strongest are almost opposite the above-mentioned star. Although the general similarity of this nebula to the well- known and brighter Ring Nebula in Lyra is noticeable, it differs in possessing these condensations, while the Lyra nebula is almost uniform in structure; and it is thought that this circumstance indicates a considerable advance of the Cygnian body from the evolutionary standpoint. Occultations of Aldebaran. On March 2nd and 29th the octultation of the bright yellow star .Aldebaran will offer facilities for several interesting observations. Those possessing small telescopes up to 4 ins. aperture should look specially for the small companion, of about the eleventh magnitude, which is considered a good light test for instruments of this size. It is within 2" of arc in distance from Aldebaran. The other minute attendant star found by Burnham about 31 ""4 distance is not considered to bo physically connected witti the Aldebarian system. At various previous occultations of Aldebaran observers have recorded a slight tendency for projection, or hangiug-on, of the star. Although this might be caused if the companion star were brighter, it is doubtful if it be real, and observations carefully made to solve this question would be welcomed. Harvard College Observatory, Report for 1905. In his report for the year ending September 30, 1905, Pro- fessor E. C. Pickering has again an enormous amount of work 10 record. With the East Equatorial over 13,000 photometric light comparisons have been made by Professor O. C. Wendell, principally with the polarising photometer with achromatic prisms. A large part of these relate to variable stars of the .Algol type, and serve to determine their light curves and times of minima. Measures have been made of four Asteroids, to determine the variation, if any, in their light. Thus from 15S0 determinations of Eunomia (15) it appears that this asteroid varies by about half a magnitude in a period of 3'' 24'5't'. With a second photometer, measures have been made of the remarkable variable O Ceti and several double stars. With the 12-inch meridian photometer, S1.2S4 settings have been made by the Director, on 148 nights. The measurement of all the Durchmusterung stars in zones 10' wide, at intervals of 5^, has been completed from the North Pole to declination — 20°. With the ii-inch Draper telescope, looi plates of spectra were taken, and 133 with the S-inch Draper telescope. The number of photographs taken during the yearis6i6i. Eclipses of Jupiter's satellites and occultations of stars by the moon have been photographically recorded, and work is proceeding with the classification and study ofthe spectra of stars of about the fifth magnitude, during which study many interesting new variables have been detected. In connection with modern observatories near, or in, large (owns, a special inquiry has been made with regard to the photographic brightness of the sky. It was found that owing to electric lights, cSic, the sky at Cambridge, Mass., is three times as bright as at points only a few miles distant, and it is suggested that it may be necessary in the future to establish an auxiliary observing station for the northern stars. Stellar photographs at .Arequipa were taken with the 13-inch Boyden telescope and the 8-ii;ch Bache, to the number of 2244. The Bruce telescope has been in full work, 523 photographs being obtained, of which 27 had an exposure of 4 hours. From a study of these, 1129 new variables have been detected, 909 being in the small Magellanic cloud. Other photographs led to March, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 38 the discovery of Themis, the tenth satellite of Saturn. This is sometimes brighter or fainter than Phcebe, and the latter appears to be variable. The Blue Hill Meteorological Station has been maintained, as before, at the expense of Mr. A. L. Kotch. During 17 kite records of the upper air, the average altitude was 6940 feet, and the maximum height attained was 11,180 feet. With hiiUoiis-soiuit's a height of 48,700 feet was reached, the temperature recorded being — 111° F. ^^^^^^ BOTANICAL. By G. Massee. Floral Colours and Pigments. TllF, colours ,,l lloucrs, Irom a biolo.^Mcal Nlandpoint, have received iiiLich attention during recent years, but, as a rule, the colour, as we ordinarily see and interpret it, has formed the main or only basis for comparison. In the Journal of the Koijal Hdrficiiltiiral Society Mr. Bidgood has treated the subject from a different and more fundamental standpoint. Plants do not inherit colour from their parents, but the pigments which possess colour or colours as their most characteristic properties. Further, if a pigment is inherited it does not necessarily follow that the colour of that pig- ment should be of the same hue as that of the parent. A plant m.ay inherit from one parent an uncoloured substance which, with a pigment from the other parent, as in the case of a hybrid, may modify the pigment so that the colour is altered. Finally, a hybrid may inherit an uncoloured sub- stance from each parent, which may re-act on each other and produce a pigmented or coloured substance. It is indicated that knowledge of this kind should prove very useful to those interested in hybridisation and the produc- tion of new colour varieties of plants, as it would prevent much time being wasted, and a striving after the practically impossible. Students of Mendel would also benefit by de- voting mure attention to the inheritance of pigment, rather than to the inheritance of colour. A flower is seen by the light given off from its surface, much of it after having penetrated to a greater or less ex- tent, and after having been more or less decomposed by the pigments present in the cells. If the pigmented particles consist of green corpuscles or chlorophyll grains, underlying a red dissolved pigment, the chlorophyll would absorb nearly all the light that passed through the red solution, and little or none w'ould reach the surface again. The result would be a dark neutral brown or black. The outer side of the llowcr of Crocus avreus has green stripes near the base. This colour is due to the combined effect of blue anthocyanin in the epidermal cells on that side, and to a yellow xanthic pigment on the other. The black blotches on the leaves of Arum n^aculntum are the result of crimson anthocyanin overlying green chlorophyll. .Subjective colours due to the interference of light in thin films, frequently seen in animals, does not appe.-ir to exist in plarils. Relations of the Algal Floras of the N. Atlantic, the Pola.r Sea, and the N. Pacific. It has long liri ri l\\ n thai a great m.iny pl.'ints in the northern hemisphere have a circumi)olar distribution. Plants of the tertiary period occupying districts around the Pole were driven .southwards to the Continents of our time during the glacial period, and on its cessation slowly wandered b.ack to their original home. .At the .same time "these plants left some of their representatives in their southern tcmpor.iry home. By these means we account for those species which every .\rctic district has in common with the mountains south of it, but not with other districts. This knowledge, however, only applies to llowering plants, and as far as m.Trine alg.-e are concerned hut little has been attempted in this direction previous to the work bv Sitnmons in the Hdfaniichcii Centrallihift. In early tertiary tim<-s the Pol.ir .Sea possessed .-i distinct flora limited from the .\tl;mtic flora by ,-1 land-bridge now .•ibsrnl. .\ similar h.arrier also separated the Pacific Ocean from the Polar Sea. On the disappearance of these barriers the Polar algae invaded the .\tlantic and Pacific, and the glacial period drove more algie south, leaving the Polar .Sea almost devoid of plant life. .\ftcr the glacial period some algae returned to their old home, and this condition of things is still in progress so far as conditions allow. .Many of the tertiary Polar species have, however, not been able to return, owing to adverse condi- tions. As a result there are now some .\llantic and Pacific .■dg» respectively that had their origin in the Polar Sea, but are now .absent from there. On the other hand, some old .\tlantic algae that became adapted to cold during the glacial period, migrated to the Polar Sea along with the returning original .Arctic alg£e. This theory accounts for the hetero- geneous assemblage of types of algae in the Polar Sea at the present day, and also for the presence of .\rctic typos in wh;U are considered indigenous s[>ecies in the .Atlantic and I'.icific Oceans respectively. On the Occ\irrence of Starch and Glxicose in Timber. A point of mucli economic i[iiport,incc ha> been announced by Professor Kirk in the TifuisadioHS of the Xew Zealand Institute. Examination of a considerable series of worm- eaten wood of various kinds showed that in every instance such wood contained starch or an abundance of glucose, and it is for the purpose of feeding on these substances that the larvw of beetles attack timber. In the case of white pine {roilocnrpus ilm ri/difnl, s) it is recommended that the trees be cut when the sii.ri.l starch has been converted into soluble glucose, and tlv liiiil" 1 iljowed to remain exposed for some time to till' .Rtion of w.itir tu dissi,l\|. out the glucose. Mycorhiza. on R^oots of Trees. The presence of mycorhiza or growths of fungus mycelium on the roots of many plants has long been known, and various investigators, more especially Frank, consider that such growths are of great service, if not even indispensable to the nutrition and health of the plant thus infected. Transeau in discussing the flora of the bogs of the Huron River Valley, in the Botanical Gazette, expresses the opinion, founded on field observations, that in Larix mycorhiza are only developed when the ground in which the plant is grow- ing lacks aeration, and more especially when the roots are surrounded by water, .\cidity of the liiedium in which the plant is growing does not favour the development of mycorhiza. Whether the fungus is of actual advantage to a plant, even when growing in a poorly aerated soil yet re- mains to he determined. These conclusions corroborate those of others who have recently studied the subject, and point to th.' conclusion that the amount of importance attached to m\corliiz;i by l'"r.uik is exaggi'rated. CHEMICAL. By C. AiNswoKTH Mitchell, B.A. ((Jxon.), F.I.C. Poisonous Plants used for Catching Fish. Till number of tropical plants which find a practical use in the catching of fish is very large, no fewer than J44 ditTerent kinds having been described by M. Greshoff. They belong to different families, but chiefly to the leguminacea;. euphorbace;c and sapindace:e. The active clieniical constituents to which they owe their toxic power are equally varied, and include alkaloids, glucosides, volatile oils, resinous bodies, pnissic acid, etc. The compounds of most frequent occurrence have been found by Dr. Kobert to belong to the saponines, the best known example of which is found in the soap-wort, in the root of the clove pink, and in the horse chestnut. When extracted from these by means of boiling alcohol saponine is deposited as a powder when the solution cools. It is readily soluble in water, and the solution forms a lather like soap, whence the name of the compound. Dry, powdered saponine produces sneezing when inhaled. Another class of substances has been isolated by Dr. GreshofT and other Dutch chemists from leguminous plants belonging to the natural order Dans, and notably from the root of /). .Uif^tica, which occurs in Java and the neighbouring islands, and has been especially studied by 388 KNOWLEDGE & SCIENTIFIC NEWS. [March, igo6. Herr Pahisch. The\' are all resinous bodies, free from nitrogen, apparently related to one another, and extremely poisonous to iish. The compound isolated from D. ellipHca is termed derriik, and has the formula, C.t, H.io Oio. The Distillation of Gold. M. Moissan, to whom \vc owe so much of our knowledge of the behaviour of chemical elements at a high temperature, has found that there is no difficulty in distilling gold in an electric furnace, and that the liquid condenses on a cold sur- face in minute crystals and threads, which behave exactly like ordinary gold in a finely-divided state. The boiling point of gold is higher than that of copper or tin. but lower than that of iime ; so that on distilling alloys of gold with copper or tin a fractional separation is effected, the gold being the last to pass over. When an alloy of gold and tin is distilled with lime, the distillate, consisting of a mixture of gold, oxide of tin, and lime, has the beautiful colour and other characteristics of the well-known Purple of Cassiiis used for colouring glass and porcelain. Hitherto this substance has only been produced by wet methods, such as treating a solution of gold in aqua rcgia with solutions of the chlorides of tin, and the new dry method of preparing it may be found of commercial import- ance. Deposits of other shades of colour can be obtained by mixing the alloy with silica, magnesia, alumina, or other oxides, in place of lime, before the distillation. Flour Dust Explosions. Fine, dry, organic dust, such as that of coal, flour, soot, or cotton, w'ill take fire with explosive violence, and man)' terrible accidents have occurred in mines and mills through ignorance of this fact. After the explosion in the Haswell Collieries in 1S44, the subject was investigated by Faraday and Lyell, who made recommendations as to better ventila- tion of the mines ; but no precautions appear to have been adopted until later accidents led to the appointment of a Royal Commission. In 1S72, a frightful disaster took place in the Tradeston flour mills, near Glasgow, but no one sus- pected the cause until Mr. Watson Smith showed that a mixture of flour dust and air would burn explosively in the same way as coal dust and air. An investigation made in 18S1 by Messrs. Rankin and Macadam, brought to light the fact that many unexplained explosions had occurred in other flour mills, notably in Bnda-Pest. These, too. were attributed to the dry flour dust having been ignited by sparks from the stone rollers, and the conclusion was arrived at that "it seems scarcely possible to guard against such accidents." Mr. Watson Smith has reviewed the whole subject in a paper read before the Society of Chemical Industry, and points out that to this day flour mills of the old type are still in use and are inevitably exposed to the same risks as the mills in 18S1, notwithstanding the fact that means of obviating all danger were devised by Mr. Simon, of Manchester. These improve- ments consisted in replacing stone rollers by iron rollers, and in the introduction of what is known as the "Cyclone"' System of collecting the flour dust. The dust-laden air from the rollers is conducted into a conical separator where, by means of the centrifugal action, the dust slides down the side to the bottom, and escapes through a small opening into a receptacle, while the air, freed from dust, is whirled upwards again, and leaves the "cyclone" through a cowl in the roof. In addition to the production of a purer flour, the method has the further advantage of preventing injury to the workpeople, who otherwise inhale the dust. GEOLOGICAL. Bv Edward A. M.\rtin, F.G.S. Glacial Beds of Triassic Age. The Dwyka Conglomerate found at the base of the Karroo System in the Transvaal is now better known as the Glacial Conglomerate, since the former differences amongst geo- logists as to the nature of the formation have all but passed awav. At one time it was generally supposed to have been of igneous origin, and great hesitation was naturally felt before accepting the glacial origin of the beds, situated as thev are in a system which is certainly not vounger than the New Red (Triassic). Mr. E. T. Mellor, F.G.S. , has studied the district lying east of Pretoria to near Middelburg, and divides the Karroo rocks into an Upper and a Lower division. The former is sometimes known as the " High- Vela Series," and consists of various grits and shales with conglomerates and coal seams, whilst the latter consists of various glacial deposits, including the Dwyka Conglomerate, and associ- ated shales and sandstones. The conglomerate averages about 50 feet thick, and may in depressions reach as much as 200 feet. The constituent boulders and sub-angular rock fr.-igments show no definite arrangement, and lie in a con- fused mass. It is noteworthy that the surface of the older rocks underlying the glacial conglomerate are frequently polished and cle;irly striated, and also that the striae exhibit a remarkable constancy of direction towards the south. Neolith fronn South Norwood. A portion of a neolithic flint implement has reached me which was found in a garden in .South Norwood, on the slope. of the hill below Grange Park. It bears a marked resemblance to one that was found by a workman in the riiornlon Hrath gravel pits some few years ago, and was Neolith from South .NorwooJ. (Natural size.) referred lo by Dr. A. E. Salter, F.G.S., in his paper before the Geologists' .Association, entitled " Pebbly Gravels." The portion of an implement now found is well preserved, although on both sides a molecular change has proceeded in the silica, resulting in a banded appearance of the white ])ortion when seen in section below. It is of excellent shape, and well polished. Nilotic Geology. The somewhat vexed question of the mutuiil relations of the Cretaceous and Eocene systems in the vallev of the Nile has been to some extent determined by some useful ob- servations which have been made by Mr. H. J. L. Beadnell, formerly of the Egyptian Geological .Survev. In the autumn of 1904 he took advantage of certain opportunities which presented themselves to him to examine the desert margins March, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 389 on both sides of the Nile Valley, between Aswan and Esna (lat. 24° to 255"). Far from the Cretaceous and Eocene forni-ritions being here at all times unconformable with one another, there is distinct evidence that the passage from the oldest to the yoimgest beds was in some localities, notably near Ain Amur, so gradual that near the junction, fossils typically characteristic of Cretaceous beds in other places, occurred side by side with forms having distinct Eocene affinities. On the other hand, in the Baharia Oasis, the un- conformity is most strongly marked. Of the Cretaceous beds, Ihe Danian stage is clearly shown, whilst above these beds, and below the Lower Libyan (Eocene), Mr. Beadnell found it necessary to classify the Esna shales as passage beds, some 197 feet thick, since they undoubtedly bridge over the period which elapsed between the deposition of the Cretaceous white chalk and the incoming of the Nummulitic sea of Koctne limes. Ripple -Ma.rked Sa-ndstone Tiles. With a ijlc:ntiful supply of slatis and tiUs fur the roofing of houses, the use of ripple-marked slabs of sandstone is not now, perhaps, so noticeable as formerly. Formerly the fissile slabs of Wealden sandstone, on which a long-ago in- coming tide had left the impress of its rip|)les, were in great demand, and many of ihr uld.r Wr.iMcn faiinhouses may be seen to be roofed willi them. The ilkustration shows a farmhouse near Bletchingley, in Surrev, roofed with some- what substantial sandstones, manv of which are very clearlv ripple-marked. These may be of' Lower Greensand age. OR.NITHOLOGICAL. By W. P. PvcKAi-T, A.L.S., F.Z.S., M.B.O.U., &c. Bird Migra.tion. The first Report of the Committee appoinlnl hv the British Ornilhologists' Club lor ilie sludv of Ihe migrations of our British birds has just been i)ublished, and forms an exceed- ingly valuable contribution to our knowledge of this subject. The work began early in 1905 when schedules were di.s- Iributed among a number of willing workers in England and Wales— lo which areas the observations are to be con- fined for the present— and to numerous lighthouses and lightships. Over 15,000 records were received, and the report in question gives the results of the analyses of these. The work for this year was confined entirely to the arrival and dispersal over the country of twenty-nine of our commonest summer visitors— the warbler, swallow, swift, nightjar, cuckoo, and land-rail being among Ihe number. It would seem from the report tiiat, in some species, at any rate— as the whin-chat and chilfchall- the birds which arrived first passed on northwards to nest, their place being taken by later arrivals; while the western and north- western counties of England were populated before the eastern and north-eastern. -Space, however, forbids a further summary of the results of the first year's work, which is full of most interesting facts, and should be read and studied bv all who are inter- ested in this subject. The great feature of this admirable digest are the maps which illustrate the movements of the species dealt with. Those who desire to obtain copies of the report should write to the publishers, Messrs. Witherby and Co., High Holborn. Bittern in Essex. The Field, January 20, records the fad tliat a bittern was seen within twenty-five miles of London on the nth of this month. It was surprised by a sportsman in some sedgy growth " surrounding a large piece of water " and was, to his crcMlit, allipwcd lo escape unha'rmi-d. Ferrviginous Duck in Suffolk. I wo examples— sex not stated— according to the Firhl of February 3 were shot during the end of January near Bury .St. Edmunds. Wall Creeper at Ecclesbourne. At the l.ist meeting of the British Ornithologists' Club an example of the wall creeper (Tkhodioma tnuiaria) was ex- hibited which had been shot while climbing about the face of the cliff at Ecclesbourne, near Hastings, on December 26, iijoi. It proved, on dissection, to be a female. This makes tile fi.urtli incurrence of this birti in (ireat Britain. Dusky Thrush in Nottinghamshire. At the meeting of the Club just referred to an example of the dusky thrush (Turdus fiiscutiis) was exhibited, which had been shot by a market gardener near (iunthorpe in October, 1905. This makes the first recorded occurrence of this bird in these islands. Fire-Crested Wren. There was ,ils,i rxliibilcl .1 ni.d.- example of the fire- crestrd wren (llcialas iguicapillus), which had been shot at Wimbledon, December 37, 1905. This marks the first oc- currence of the bird in Surrev. Another example, also a male, was exhibited by Mr. W.'R. Ogilvie (irani, which had been picked up in a dying condition' at .\bbev Wood, Kent, January 10, 1906. An Abnormal Eider. A more caiclul scrutiny of our eider ducks would seem to show that occasionally at least specim<'ns occur with a more or lees distinct V-shaped mark on the throat hitherto supposed to obtain only in the Pacific eider. An example of this kind w.-is exhibited at the meeting above referred to l)y Mr. Howard Saunders, which had beei'i killed on December 7, 1905, near Stromness, Orkney. Whether this peculiar mark is the result of a cross with the Pacific species which oc- casionally occurs, in our waters, or is independently developed, it is impossible at present to say. PHYSICAL. Hv Ai.iKi.i> W. I'oKn K. P..Se. Do Rontgen Rays Disintegrate Atoms? All substances when illtnninated by Kunls^eu rays or by Becquerel rays of the ; type give out a complex secondary radiation, part of which at least is wholly dift'ereut in character froiu the primary radiation. For example, the secondary radiation due to the absorption of Rontgen rays consists in part of negatively charged corpuscles or electrons, although no such charged particles exist in the exciting rays. This suggests that there may be some breaking up of the substance upon which the exciting rays impinge— a disintegration of the same type as that which takes place spontaneously in radio- active substances. On the other hand, the production of streams of electrons by no means proves that such disintegra- tion is a fact; for according to modern theories of electric conduction there exist numerous electrons in a conductor — and what substance is not a conductor ?— which are only 390 KNOWLEDGE & SCIENTIFIC NEWS. [March, igo6. loosely attached to the atoms and not apparently forming an integral part of them. They seem to float about very much as the particles of gas dissolved in a liquid. The electrons which leave the substance under the action of Kontgen rays may simply be these unattached ones, and if so the existence of the streams is no proof of atomic disintegration. This (piestion has recently been tested by Professor Bumstead (working in the Cavendish Laboratory), who argues that if disintegration is brought about there must be a corresponding release of atomic energy, which will appear — in the main — as heat, and which will raise the temperature of the substance. For equal absorption of Rontgen rays the amount of heat produced from two substances might be expected to depend upon the material and be greater in amount than that of the incident rays, which merely play the part of a trigger. But if no disintegration occurs the heat produced should be equal to the energy- of the incident radiation (minus the small amount carried away by the secondary radiation), and should therefore be practically the tame in both cases. The experi- mental method employed is based upon these considerations. It is in brief a sort of reversed radiometer. A radiometer — such as was first devised by Crookes — acts owing to the in- cident light warming the vane which is repelled by the forces in tlu-iiiy between the vane and the fixed wall of the tube. It comes to the same thing if the wall itself is warmed while the vane is made transparent so as to keep cool. The latter arrangement was most suitable in the present case. The walls can be made of the metal under investigation, and the move- ment of the suspended vanes is due to the warming of the walls by Rontgen rays, and is a measure of the heat produced. Only lead and zinc have been experimented upon so far. Their thicknesses were chosen so that they absorbed the same amount of radiation, and under these circumstances the experimental result is that about twice as much heat is gene- rated in the lead as in the zinc. Professor Bumstead examines the numerous sources of error to w^hich the mode of experimenting is subject ; and also other modes of explaining this difference in heat production ; but concludes that the evidence is in favour of the view that true atomic disintegration is brought about by the absorption of Rontgen rays. The experiment is, however, beset with pitfalls, and physicists will probably await the results of further experiments, which are promised, and in which it is proposed to employ other means of measuring temperature, such as a thermopile. Anyone acquainted with the vagaries of a radiometer will regard with caution the conclusions arrived at from these preliminary experiments, even though he may be willing to grant their plausibility. (" Philosoi'HIcai. Maga^ink." Feb. njo6.) Conductivity of the Vapour from a. Mercury Arc. The Hon. R. J. Strutt showed some years ago that mercury \apour under ordinary conditions is a very perfect non-con- ductor of electricity. C. D. Child, in a recent paper read before the American Physical Society, shows that the vapour coming from a mercury arc is highly conducting. A lumi- nous space gradually spreads out from the arc, and the front of this region has the greatest conductivity and the greatest luminosity. He considers that the conductivity is not due directly to ions coming from the arc, nor to rays sent out by it, nor to leakage over the surface of the glass, and probably not to the high temperature of the gas. He suggests as prob- able an explanation given by Merritt, viz., that when ions recombine they are at first in a condition of unstable equilib- rium much like the atoms of radioactive matter, and that many of these combinations break up again into positive and negative ions. The Efficiency of a Welsbach Ma.ntle. A fresh study has been made by Rubens of the light from a Welsbach mantle with the object of elucidating the reason of the extraordinary efticiency of this source of light. The fact that the small addition of cerium oxide (-8 per cent.) to the thorium oxide which forms the main body of the mantle ((ji)-.; per cent.) enormously increases its light-giving power has induced many— especially among chemists — to regard the light as being essentially of phosphorescent origin — i.e., as depend- ing in the main upon chemical changes (or catalytic action) rather than upon the high temperature to which the mantle is raised. It is well known that at a given temperature, the radiation which depends upon temperature can never exceed that from a " perfectly black body " at the same tem- perature. Since a mantle without ceria and one with it give out very different light wlien placed in the same Bun sen flame, the assumption that the additional light is not due to the tem- perature has at least some plausibility. But nothing except a thorough study of the radiation can suffice to settle this in- teresting question. For there is a tacit assumption amongst the holders of the chemical theory that the two mantles placed successively in the same flame will have the same temperature. It is clear, however, that if one radiates much more than the other it will necessarily adjust itself to a /oii'ic tem- perature ; for it is the gradient of temperature from the flame to it which controls the flow of energy to the mantle and which maintains this mantle at a constant temperature in spite of its radiation. The one that radiates most has to receive most, and a greater gradient is necessarily required to keep up the supply. Those who claim that no chemical change is responsible for the light assert that the more lumi- nous mantle owes its luminosity to the fact that at a given temperature it is a bad radiator for that tcmperciturc ; but that owing to this parsimony it is able to keep at a higher tempera- ture than its more generous companion ; and everyone is agreed that a higher temperature tends to produce greater efficiency. The upshot of Rubens' measurements is that a mantle stained with iron oxide (and therefore a good radiator at a given temperature) kept at atemperature of about 1050" C. in a flame ; whereas the unstained mantle rose to about 1500 C, while the estimated value of the temperature of the bunsen flame itself is about iSoo° C. After making allowance for the non-continuous nature of the surface of the mantle, it is shown that /or no wave length is the radiation as great as that from a perfectly black body at the temperature of 1500^' C. ; and that the total energy radiated is only one thirty-third part as great as from such a body. .Although then it cannot be denied that phosphorescence may play some small part, yet it is altogether unnecessary to call in its aid to explain the amount of radia- tion. Experiments on a mantle of pure thorium oxide show that the radiation from it contains almost no light rays, but in other respects is very nearly the same as for an ordinary mantle. On the other hand, a mantle of pure cerium oxide gives out radiation proportionately very rich in luminous radiation, and also of radiation of very long wave length. Vox the important region of wave lengths immediately in the infra-red {i.e., X = i to 8-millionths of a metre) it is a bad radiator. It would not do, however, to use such a mantle, for its temperature (like the iron-oxide one) keeps very low. But the addition of a small amount of ceria to thoria much increases the luminous radia- tion of the latter without sensibly alterating the radiation in the immediate infra-red. Thus the behaviour of an ordinary mantle can be adequately represented by adding together the separate radiations of the constituents of the mantle. The opposite supposition, that the light is due to phosphorescence, requires that the greater part of the effect should arise only when the constituents are present together. This result seems to be in conflict with the new experimental data. ZOOLOGICAL. i!y K. LVDEKKEK. The Intestinal Appendages of Birds and Ma^mma-ls -An important contribution to our knowledge of the intestinal anatomy of mammals has just been published in the Transac- tions of the Zoological Society, Dr. Chalmers Mitchell, the Society's secretary, being the author. Perhaps the most generally interesting feature in this memoir is the identifica- tion of the paired •' c;eca," or blind appendages of the intes- tine, of birds with the, usually, single ca-cum of mammals. These ca;ca occur at the junction of the small with the large intestine ; and while in ordinary perching birds they are reduced to small nipple-like buds of no functional importance, in many other birds — owls for instance — they form quite long receptacles. Among mammals, the horse and the dog may March, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 391 be cited as instances where the single cascum is of large size, this being especially the case in the former, where it is of enormous dimensions ; in human beings, on the other hand, the caecum is rudimentary, and best known in connection with "appendicitis." The existence of paired cteca was previously known in a few armadillos and ant-eaters, but Dr. Mitchell has now shown that they are quite common in these groups, while he has also recorded their occurrence in the hyrax and the manati. With the aid of these instances of paired c;Eca, coupled with the frequent existence of a rudiment of its missing fellow when only one is functional, the author has been enabled to demonstrate conclusively that these double organs in birds correspond in relations with their normally single representa- tive in mammals. Teeth of Early Carnivora. Much difference of opinion has obtained among naturalists with regard to the aflinities of certain extinct carnivorous mammals from the Tertiary ftrata of South America, some authorities regarding them as more akin to the predaceous marsupials, while by others their relationships are believed to be closer with the primitive European and North American Carnivora known as creodonts. This opens up the wider question as to the existence of a direct relationship between creodonts and marsupials. On this difficult question con- siderable light has been thrown by investigations into the structure of the enamel of the teeth of the two groups, the results of which were recently communicated by Mr. Tomes to the Zoological Society. According to the author, marsupial teeth show in the structure of their enamel a well-marked peculiarity, namely, the free penetration of the enamel by tubes continuous with those of the dentine ; while recent Car- nivora, the descendants, more or less direct, of the creodonts. also present a disposition of the prisms of their enamel some- what unusual amongst mammals. Teeth of Hycriuniun and other extinct genera were examined, and in none of them were marsupial characters observed. On the contrary, in most cases characteristic carnivorous patterns were found, so that in Oligocece and Eocene times the enamel of the ancestral Carnivora had already attained the full specialisation charac- teristic of the modern group. Weights of Whales and Dinosaurs. With characteristic boldness and originality American in- vestigators have recently been making the attempt to estimate the approximate " live- weights " of the huge dinosaurian reptiles of the Oolites, such as Diplodocus and Droiitosaiinis. Although at first sight the attempt might appear almost hopeless, their method of going to work has been so thorough and well thought out that there appears to be considerable probability of the estimates at which they have arrived presenting a fair approximation to the reality. The plan adopted was to make a modt 1 of the entire reptile, as deduced from a care- ful study of the skeleton, on a scale of one-sixteenth the natural size. The cubic contents of such a model multiplied by the cube of 16 would indicate the probable amount of water displaced by the reptile when in the flesh. To arrive at this result, one of the miniature models of Broiilosiiunis (the length of whose skeleton is 66.5 feet) was cut into six pieces of convenient size for purposes of manipulation ; and the equi- valent water-displacement of each of these fragments deter- mined with great accuracy in the laboratory. Erom this the water-displacement of a model of the natural size was calcu- lated by means of the above-mentioned formula, which gave as a result the displacement of 34} tons by the entire auimal. Since, however, Broiitosanrus is believed to have walked along the bottom of the ancient lakes in search of food to depths which would cause its whole body to have been submerged, it is probable that the reptile in life was slightly heavier than water, and to allow for this an addition of about ten per cent. was made to the calculated weight, thus bringing the final estimate to a total of 3.S tons. Vast as is this weight, it is, however, only about two-thirds of the estimated weight of the heaviest whales, which is presumed to be not less than 60 tons. Further information with regard to tins latter estimate appears desirable, and it would be interesting to know which of the larger species is really the heaviest. The C.reenland right whale would, from its great bulk, of course weigh well ; but as the maximum length of this species was estimated by Sir William Flower at from 45 to 50 feet, while the male sperm- whale is known to measure from 55 to 60 feet, it is possible that the latter monster would scale heavier than the former. On the other hand, despite its length of from So to 85 feet, the huge Sibbald's rorqual, on account of its '• clipper-built " form, would probably weigh less than either the Greenland whale or the sperm-whale. Any estimates of the weights of whales based on trustworthy data would be of much interest. It may be added that the weight of the African elephant " Jumbo " was only 5i tons, and although some individuals of the species may perhaps be somewhat heavier, it is clear that elephants are not in the running in comparison with the American estimate of the weights of dinosaurs. The Flight of Flying-Fishes. In the course of a memoir on fossil flying- fishes, published in the Year- Book of the Austrian Geological Survey, Dr. O. .\he\ reviews the much-discussed question as to whether the existing representatives of such fishes — which belong to two distinct groups, the flying-herrings, or true flying-fishes, and the flying-gurnards — really use their " wings " after the manner of bats, or whether such wings merely serve the same purpose as the flying-membrane or parachute of the flying-squirrels. In the case of both flying-herrings and flying-gurnards, the author denies that the wings are ever used as instruments of active flight. As regards the former. Dr. Abel's opinion agrees with that of the majority of competent observers. In regard to the flying-gurnards it has, however, been stated in the " Cambridge Natural History " that these fishes differ from the members of the former group in that the wings are moved rapidly during the courre through the air, thus producing a mode of flight recalling that of many grasshoppers. This assertion is, however, controverted by Dr. .\bel, who urges that such movements as take place in the wings of fljing- gurnards are similar in their nature to the vibrations which are admitted to occur in those of the flying-herrings or true flying-fishes. The author's statement of the whole case is summarised as follows : — " It may be taken as certain that the initial impetus by means of which flying-fishes of both kinds launch themselves is due to powerful screw-like movements of the tail-fin. The wings are in no sense propelling organs, but act simply as parachutes." In striking contrast to this conclusion is one arrived at by an author in the January number of the Anuah and Ma!;a:inc of yatnral History. According to this, the aeroplane theory, as the above maybe called, is an absolute mechanical impossi- bility, and the flight of flying-fishes is due to incessant and ex- tremely rapid movements of their wing-like fins. A Male Fish-Nurse. It has long been known that the males of the strange-looking pipe-fishes take charge of the eggs as soon as they leave the bodies of the female parents, and nurse them in a special pouch on the under side of their own bodies; but it appears to have been reserved for an American naturalist to observe the actual manner in which the transfer of the eggs takes place. I'rom his account, it seems that the male and female fishes entwine their bodies in the form of a double letter S, and that in this position the eggs are passed from the mother to the pouch of the male. As might have been expected, all the eggs are not transferred at once. .-Xfter the first transfer- ence all the eggs of this batch are in the upper part of the pouch, where no more can be received until these are shaken down into the lower end. "To bring this about," writes the narrator, " the male performs some very curious movements. He stands nearly vertically, and, resting' his caudal fin and a small part of the tail on the floor of the aquarium, bends back- ward and forward, -and twists his body spirally from above downward. This is repeated until the eggs have been moved into the posterior end of the pouch." These processes are repeated until the pouch is filled. In about ten days the young pipe-fishes are hatched. Papers R.ead. At the meeting of the Zoological Society held on January 16, Mr. O. Thomas exhibited skulls of a "forest-pig from the Cameroons district, which he referred to a new species, under the name of Ilylochirnts r'uiiatcy. Mr. W. S. Fox read a paper on bones of the lynx from a Derbyshire cave; Mr. C. S. Tomes discussed the structure of the enamel of the teeth in Carnivora and marsupials ; Mr. F. E. Reddard described the results of investigations into the anatomy of snakes ; and Dr. J. Koux con- tributed a list of the species of a particular group of toads. 392 KNOWLEDGE & SCIENTIFIC NEWS [March, 1906. Conducted by F. Shili.ington Scales, p.. a., f.r.m.s. Elementary Photo-micrography. [Cpntituicd from pag( 362.) The iitmosl crirp iiuisl he taken in ohservinq- whether this disc of lig:ht is u-:illy iinifnirii; i| is somewhat decep- tive, and a shght rc-adjiistmcnt may sometimes make all the difference, hut if it be not uniform, the photo- graph will show unequal illumination, that is, one side will be rather darker than the other, which is not satis- factory, though too often seen. The sub-stage con- denser and even the auxiliary condenser mav need sJight re-adjustment and re-focussing to obtain the best results, but any great alteration will not be found satis- factory. A little patient exjK'rimenting, however, will be found to teach more than many pages of sugges- tions. The advantage of the optical bench or of the parallel slides is now evident, and if there is any change of ob- jective a slight re-adjustment of the condenser is all that is necessary. It saves much labour if everything is lei I in place, except the microscope, and the position ol thr laltiT is carefully marked, or stops made for its stand, but if the auxiliary condenser and illuminant must be removed, then some means should be .adopted ot so arranging or marking them that they can be, without (lifliculty, brought back exactlv to their previ- ous position when required. So far, we have done all our focussing upon a piece of ground glass, but this, however fine it may be, will be found too coarse for the final focussing. We must, therefore, have a further frame of plain glass, fitting into the same slides, and once again I must insist on the importance of having the inner surface of this in exact correspondence with the sensitive film of the photographic plate when in its dark slide and in posi- tion. It is not a bad plan to fasten a thin circular cover-glass with Crmada balsam, in the very centre of the inner and rough side of the ground-glass screen. This makes a little transparent disc for examining the photograph, but it is scarcely big enough to be an eflici^'nt substitute for the complete plain-glass screen. In using the latter we have, of course, no surface to form an image upon, and we therefore need a focussing lens of some sort. This may be of the simplest form, but its magnification should not be too high and yet its " depth of focus " should not, for ma.nifest reasons, be too great. A dissecting loop in a cardboard or wooden ring will serve, or one of the ordinary tripod magnifiers, but suil;ible lenses with a ring for adjustment, i.in be bought for a few shillings at most opticians. An ink mark is made on the inner surface of the plain glass screen, the focussing lens is brought in contact with the other or outer side, and then adjusted so as to focus the ink-mark through the glass. Dr. Bousfield recommends a double convex spectacle lens of about eight inches focal length, w^hich may be mounted in a cardboard or other tube of suitable length to focus such an ink-mark. (To he conlinucd.) Journal of the Quekett Microscopical Club. The half-yearly volume of this journal contains a de- laif'd list of 140 species of I'Oraminifera, collected by Mr. .Arthur (larland, from the shore-sand at Bognor, Sussex, with four illustration plates, also an illustrated article on the genitation of the Tsetse fly, by Mr. W'.ilter Wesche. Mi". F. P. .Smith contributes a list of all the species of spiders of the Walekciwi'ria group, wliiih \y.\\v occurred in the British Isles, and a descrip- tion 111 .1 spider found at A'armouth, which he believes to be a new species of the Erigone group. The Journal, in accordance with the economic policy of the Club, is iiinsiderablv reduced in size, which is a matter for rep ret. R-oyal Microscopicevl Society. The .annual meeting w.as held .at 20. Il.anover Square on l.anuary 7, the President, Ur. D. H. Scott, in the chair. Attention was called to a donation from M. Nachet, a Fellow of the Society, of six micro- daguerrotypes of blood, milk, crystals, &c., set in a frame. They were taken with the electric light by M. Leon Foucault in the year 1844, and are probably the oldest of their kind in existence. The photographs are of undoubted excellence, and will compare favourably with many of later date. There was also a donation of 15 slides of the Oribatidse from Mr. N. D. F. Pearce, to supplement the collection presented by Mr. Michael. Some excellent photo-micrographs of diatoms and Podura scale were sent for exhibition by Mr. F. A. O'Donohue. The report of the Council and Treasurer's statement for 1905 were read and adopted, and the n.ames of the officers and Council elected for the en- suing year were announced. Dr. D. H. Scott having been elected as President for a third term. The Presi- dent delivered his annual address, the subject being " The Life and Work of Bernard Renault," illustrated with numerous lantern slides. Quekett Microscopical Club. .\l the nn-etlng held on |anu.irv iq at 20, Hanover -Square, Dr. \i. J. .Spitta in the chair, ^h•. R. T. Lewis delivered a lecture on " The Senses of Insects," deal- ing more especially with sight and hearing. Compari- son ha\ing been made with the physiology and anatomy of such .senses in man, and stress having been laid upon the important part played by psychological factors, the lecturer explained the theory of " .Sympathetic \'ibra- tions " and its possible applications. It was suggested th.at as insects li\e in the same light and air as man, similar, or, at least, analogous structures should be looked for, but that there was every probability that they were capable of appreciating a far greater range of vibrations of both light and sound, especially in the direction of the shorter wave-lengths. The auditory organs of insects presented a great variety of structure, those of the Orthoptera most nearly complying with what we might expect to find — organs designed to ap- preciate such sounds, for instance, as we might our- selves hear; but their position and number varied con- siderably in different families. It was considered that in addition to sight and hearing insects possessed the sen.scs of taste, smell, and touch, and that some were endowed wth the "sense of direction." Mr. Lewis made an interesting statement regarding the figure in Carpenter reputed to be a reproduction of a photograph made by Exner through an insect's compound eve, call- ing attention to the fact that at ;i meeting of the Royal March, igo5.] KNOWLEDGE & SCIENTIFIC NEWS. 393 Microscopical Society on Xovember ig, 1890, Professor Bell exhibited a print of the original photograph, which he (the present lecturerj had roughly copied in his note- book, and which showed the letter R the right way roimd and not rev<'rsed as in Carpenter. Barnes Dissecting Microscope- Messrs. .\. !■;. Stalry and ( 'o. ha\c recently brought to iny notice a simple dissecting microscope made by the Bausch and Lomb Optical Co. , which is both practi- cal, serviceable, and inexpensive. The body is of neatly finished light wood shaped to form hand rests. The stage is a glass plate, easily removable for cleaning. The mirror is as large as the stage, giving effective illumination. A black or white metal plate can be laid over the mirror when a black or white background is desired. The lens carrier is adjustable for focussing. The base forms a hinged wooden box with receptacles for magnifiers, tweezers, dissecting needles, &c. The whole stand, including an inch doublet lens with large flat field and good definition, costs onlv half a guinea. (L,C( Notes and Queries. .1., //;///. — I have put your query before a gentleman in Cambridge who is an authority on the Carboniferous Rocks, &c., and he considers that Harker would be most suitable for your purpose, but as you say you have this and it is not quite what you want, he suggests that you should endeavour to see Hatch's " Introduction to the Study of Petrology " and " Text- book of Petrology "; Geikie's " Structural and Field Geology," and Rutley's " Study of Rocks," and see if one or more of these will help you. Cole's " .•Mds to Practical Geology " is also useful. Of course, you will be aware, that the recog- nition of the constituents of rocks cannot be gained from pictures in books without a preliminary broad and general study of the subject. There seem to 'be no books dealing e.xclusively with the special subject in the way you require. I regret the oversight to which you call my attention. D. B., MaiichcsUi'.—l think both the books you mention are very suitable for your purpose. Strasburger is perhaps a little better than Bower for anyone working alone and unaided. I think you would find Watson's " Praxis " microscope satis- factory for all kinds of work, and would suggest vour ob- taining with it :■; and i inch objectives (Parachromatic series), the i^ being more generally useful than the A inch, and the ;| having a N.A. of -87, and a No. 2 ocular.' This would cost you, with case, £6 los., but I strongly recommend your adding a " Scop " .Abbe Condenser, with iris diaphragm, and an extra No. 4 eyepiece at a total cost of j[y 1 2s. 6d. C. C. Dobell and C. IV. Archer.— I think the "ultra-micro- scope " to which you refer must be an allusion to Dr. Sieden- toff and Dr. 2sigmondy's apparatus for the making visible of " ultra-microscopic particles." Vou will find an accomit of this in the "Science Year Book" for 1905, article "Micro- scopy," page 117, with further remarks in the issue for igo6, page 107; also in the Journal of the Royal Microscopical Society for October, 1903. The principle in brief is the focussing of an arc-light upon a small spectroscopic slit and condenser so as to pass a narrow beam of light at right angles to the optic axis of the microscope upon the particles to be made visible. According to Lord Rayleigh, there is nothing except lack of light to hinder the visibility of any object, how- ever small ; but if its dimensions are much less than half a wave-length, its apparent width will be illusory. In other words, the existence of the object can be shown if only the light be strong enough, but this will be no guide to its real appearance. It may be of interest to add that, accepting the size of a medium size molecule as 6^;i, a specific intensity of luminosity considerably exceeding the power of the sun's rays would be necessary to discern such molecules. It is advisable to lay particular stress upon the important difference between the mere making visible of an object and the seeing of it as it really is, as I find many workers with the microscope failing to realise this distinction, and thus entertaining erroneous expectations. T. H. Russell, Edj^bastan. — The only way to find out the magnification of eyepiece and ocular is to measure such magnification, and the easiest way is to project the image of a micrometer at a distance, as explained in Carpenter and other books on the microscope, and to make the necessary simple calculation. If you project the image of the micro- meter on a sheet of paper at ten inches from the eye-lens of the ocular you will obtain a similar, if less accurate, result, but the distance }nust be fen inches if it is to correspond pretty closely with the magnification as seen visually through the uiicroscope, because ten inches is the normal visual dis- tance. If your paper is fiu"ther away the magnification is proportionately greater, and no longer corresponds to that given when you look dowu the microscope tube. It must be evident that alteration of the tube-length will alter the magni- fication visually, and in just the same way upon the paper, but the measurement is always taken at ten inches from the tube length because that remains the visual distance of the eye whatever the tube length. .Vdjust the tube length as you will, you must always measure the projected image ten inches away, or, if [Hore, you must reduce the result to what it would be at ten inches. I hope this is quite clear now. Rev. ]. B. Williams. Exniinster. — Paraffin of various melting points is used for embedding and infiltrating specimens, one melting at about 50° C. being perhaps the most generally use- ful in a room temperature of about 16^ C. With rocking microtomes a somewhat harder paraffin is better. Hard objects naturally require a harder paraffin than soft ones. Paraffin of various melting points can be readily obtained, but if your paraffin is too hard, you had better mix it with some of a lower melting point, rather than with any other substances. The paraffin in a section can be got rid of by soaking in .xylol. Tissues are dehydrated with alcohols of variously graduated strengths, s\ich as 30 per cent., 50 per cent., 75 per cent., and g6 per cent., taking care that sufficient time is allowed in each. Before embedding, the object must be soaked for a considerable time in cedar oil or clove oil. .Vfter the paralfin has been got rid of, you can proceed to stain at once in alcoholic stains, but if watery stains are used the object nnist be first passed back through the alcohols in reverse order, and then before mounting in Canada balsam the de- hydration must be gone through again, finishing with a final soaking in xylol, cedar oil, clove oil, &c. The best all-round stains for vegetable tissues are ha;matoxylin, borax carmine (3 per cent, carmine to 4 per cent, borax in 70 per cent, alcohol, a concentrated solution being first made and after- wards diluted with an equal amount of 70 per cent, alcohol), methyl blue, and methyl green. \'egetable tissues ni'ist be first hardened for some days in methylated spirit. Cross and Cole's "Modern Microscopy" (4S.i contains very clear instruc- tions for elementary mounting, and my own " Elementary Microscopy " (3s.) has also a chapter on the subject. {Communications and Enquiries on Microscopical matters should be addressed to F. Shitlington Scales, "Jersey," St. Barnabas Road, Cambridge.'i 394 KNOWLEDGE & SCIENTIFIC NEWS. [March, 1906. The Face of the Sky for March. Bv \\ . Shackleton, F.K.A.S. The Sun. — On the ist the Sun rises at 6.49 and sets at 5.37; on the 31st he rises at 5.41 and sets at 6.28. The Sun enters the sign of Aries at i p.m. on the 21st, when Spring commences. The solar disc continues to be well marked with sun- spots, and recent spectroscopic observations of the Sun's limb show many active prominences. The position of the Sun's axis, equator, and helio- graphic longitude of the centre of the disc is shown in the following table : — Date. Axis inclined from N. point. C eniie of disc S. of Sun's Heliographic Longitude of Equator. Centre of Disc. Mar. 2 21° 48' W 7° 14' 205° 26' .,7 ■-■ 22° 59' \\ 7° 15' 139" 33' ,. 12 24° 0' W f 12' 73° 38' ,.17 •• 24° 51' W 7'-' 5' 7° 44' ,. 22 2f 32' W 6° 56' 301° 49' ..27 .. 26'" i' W C° 43' 235° 54' The Zodiacal light should be looked for in the west for a few hours after sunset. The Moon : — ., Date. Phases. H. M. Mar. 3 . . ., 10 .. .. 17 •■ > .. .24 •■ D First Quarter 0 Full Moon a Last Quarter • New Moon 9 28 a.m, 8 17 p.m. II 57 a.m. II 52 p.m. ■'" OccuLTATiONS : — The following are the occultations of the brighter stars visible at Greenwich before mid- night. Disappearance. Reappearance. Star's "2 Date. Name. 1 Angle from Angle from rt Mean , Mean ^ Time. N. Ver- Time N. Ver- pomt. tex. point. tex. pm. pm Mar. I f Tauri . . . . 4'3 6.14 121° 101° 7-9 205° 176° 2 Y Tauri . . . . 3'9 0.41 116° qq'- 7-45 218° iqo" ^ 1 ^nr, _ _ 3 y II. 51 114° 74'- 12.40 235° 198" '■ "^ ' • 5'i 5-47 15° 51" b.3 349° 24° Tiii. I'l.-vst is.^Mercury (Mar. i, R.A. 2^^^ 16"; Dec. S. 5° 56'. Mar. 31, R.A. i'' o" ; Dec. N. 10° i') is at greatest easterly elongation on the i8th, and should be looked for in the west shortly after sunset for a period of four or five days on either side of the date of elonga- tion. Although the elongation is only i8^°, it is a favour- able one on account of the large angle at which the planet sets to the horizon. Venus (Mar. i, R.A. 23'' 2^ ; Dec. S. 7" 44'. Mar._3i, R.A. i'' 19"; Dec. N. 7' 21') is an evening star in .•\quarius, but not well placed for observation. Near the middle of the month the planet sets about half-an-hour after the Sun. Mars (Mar. i, R.A. ih 8'"; Dec. N. 7° 3'. Mar. 31, R.A. 2i> 30m; Dec. N. 15'^ 4') sets about 9.20 p.m. throughout the month, and may be observed shortly after Sunset looking west. The lustre of the planet is, how- ever, feeble, as he is at a point in his orbit situated at a great distance from the earth. Jupiter (Mar. i, R.A. 3'' 47™ ; Dec. N. 19° 18'; Mar. 31, R..A. 4'' 6"'; Dec. N. 20° 20') continues to be a con- spicuous object in the evening sky; about the middle of the month the planet sets shortly after midnight. The planet is now describing a direct or westerly path, and thus he appears to be moving away from his position near the Pleiades towards .Aldebaran. The equatorial diameter of the planet on the 15th is 37"'2, whilst the polar diameter is 2"-4 smaller. The following table gives the satellite phenomena observable before midnight : — 5 lin. Oc. D. lo 58 II Tr. 1. 8 7 , Sh. I. 9 25 12 ■Ir. K. 10 21 Sh. E. II ,S Sh. 1. 7 24 n tc. K. 8 56 Sh. E. 9 31 '■i 'i'r. 1. 8 45 19 Sh. 1. II 21 Tr. E. II 23 20 j Ec. R. 8 9 I. Tr. I. I. Sh. I. I. Oc. D. in. Tr. E. I. Ec. R. I. Tr. E. I. Sh. E. IL Ec. R. I. Oc. D. II. Tr. I. I. Sh. I. I. Tr. E. P M.'s H. M. Q Mar ID 5 20 II 20 21 7 25 8 31 23 ID 52 24 6 48 27 8 2 10 45 28 9 24 30 10 34 31 7 44 8 47 I. Sh. E. I. Ec. R. II. Oc. D. III. Ec. R. II. Sh. E. I. Tr. I. I. Sh. I. I. Ec. R. III. Ec. D. II. Sh. I. II. Tr. E. 9 58 7 16 8 25 7 25 8 35 8 32 9 40 9 12 9 27 8 32 " Oc. D." denotes the disappearance of the Satellite behind the disc, and " Oc. R." its re-appearance ; " Tr. I." the ingress of a transit across the disc, and "Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across the disc, and " Sh. E." its egress. Saturn (Mar. i, R.A. 22'' 33™; Dec. S. 10° 45'. Mar. 31, R.A. 22h 4711 ; Dec. S. 9'" 28') is a morning Star rising about 6 a.m. near the middle of the month. Uranus (Mar. 14, R.A. 18'' 35™; Dec. S. 23° 29') is not well placed for observation ; the planet rises about 3 a.m. on the 15th. Neptune (Mar. 14, R.A. 6I1 33"; Dec. N. 22'' 18') is due south at 7.7 p.m. on the 14th. The planet is situated about 3" S. and ij' W. of the star e Geminorum, but is difficult to identify among the numerous small stars in the neighbourhood. Meteor Showers : — Radiant. Near to Date. R.A. Dec. Characteristics. Mar. 1-4 . . 14 .. 24.. h. m. II 4 16 40 10 44 4- 4° + 54° + 58° T Leon is /i Draconis ('iUrsseMaj Slow ; bright. Swift. Swift. Minima of Algol occur on the 2nd at 8.7 p.m., 22nd at 9.50 p.rn., and 25th at 6.39 p.m. Double Stars. — 7 Leonis, X.^ 15™, N. 20' 19', mags. 2, 4 ; separation 5"-S. In steady air, the prime requisite for double star observations, this double maybe well seen in a 3-in. telescope with an eyepiece magnifying about 30 to the inch of aperture, but on most nights one with a power of 40 is better. The brighter component is of a bright orange tint, whilst the fainter is more yellow. , Leonis, XI.'' 19", N. ii° 5', mags. 4^, 7^ ; separa- tion 2"-5. A pretty double of different coloured siars, the brighter being yellow, the other blue. This object requires a favourable night and a fairly high power on small telescopes. a Leonis (Regains) has a small attendant about 180" distant, magnitude 8-3, and easily seen in a 3inch telescope. a Canum \"enat. [Coi- Caroli), XII.'' 52"", N. 38° 50', mags. 2-5, 5-5, separation 20"; easy double, can be^seen with moderately low powers, even in 2-inch telescopes. 395 KDomledge & SeleDtJHe fleais A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. 17. [new series.] APRIL, 1906. SIXPENCE NET. CONTENTS^See page VII. Astronomical Photography. Hints to Amateurs Regarding Apparatus and Methods of Working. By Alexander Smith. In dealing with astronomical photography from a practical standpoint, it may be explained at the outset that there is no single optical appliance suitable for all classes of work. .Small nebula and dense stellar clusters require a telescope of sufficient focal length to give an image on a sufficiently large scale to exhibit structure, or to resolve crowded clusters into their in- dividual components. For example, a focal length of eight feet is insufficient to resolve the central portion of such objects as M. 13, the great cluster in Hercules, while a similar instrument, when applied to some of the small but well defined nebula; in the constellation \'irgo, gives an impression on the plate no larger than that of a single bright star. The result to be aimed at in deal- ing with such bodies is to secure as large a photographic image as possible, w'hich necessitates foca.1 length, and, in order to bring the exposure within reasonable limits, a correspondingly large aperture. The reflector with its single optical surface, absorb- ing as it docs a minimum of light and giving at the same time the requisite correction for chemical rays, has so far proved the most popul.ir form of photo- graphic telescope in the hands of both amateur and professional, and the best all-round results have probably been obtained with specula having a ratio of aperture to focal length of f/4 or f/5. It has been found that with the sensitive plates now in use a re- flector having an angular aperture of f/4 will record the faintest st u's visible in the largest telescopes with an exposure of about i hour 30 minutes. If it is desired, however, to obtain impressions of large diffused nebulosities, such, for example, as that outside the Pleiades group discovered by Professor Barnard in December, 1893, on a pl.itCi which had received an exposure of 10 hours, or of the large encircling nebula in the constellation of Orion, :dso successfully photo- graphed by the same astronomer, then the ordinary telescope on account of its small field is altogether useless, and recourse must be had to a lens of short focus, which not only gives the requisite wider angle, but at the same time greater rapidity. Dr. Max \Volf has shown that his 2\ in. aplanatic doublet is five times more effective for the delineation of nebulae than the 13 in. Henry photographic refractor. On the other hand, it was found to be 32 times its inferior in record- ing impressions of stars (" Knowledge," December 2, 1895, p. 280). With such lenses — and those of the Petzval and stigmatic types are more particularly re- ferred to — much original work may still be done, and, as they can be readily and effectively mounted on small clock-driven equatorials — either reflector or refractor — their use comes within the scope of amateurs, who may be already provided with such equipments. With a doublet lens of the portrait type, having an effective aperture of from 2 to 6 inches, and a focal length corre- sponding to an angular aperture of from f/3 to f/5, exquisite photographs of extended nebulosities, wide clusters, or of regions of the Milky Way can be readily obtained. Such lenses are also highly suitable for securing records of large comets, or of stray meteors, which may happen to cross the region covered by the plate at the time an exposure is taking place. In selecting a lens for any particular kind of work it has to be kept in view that for photographing large faint nebulous masses the duration of exposure necessary to bring out a certain amount of detail is very appreciably shorter with a small lens than with a large one, notwithstanding that their angular apertures may be precisely similar. This is due to the circum- stance of the smaller lens presenting a greater amount of contrast, and it is to this factor that the duration of exposure largely depends. With points of light such as a star the duration of exposure is determined by the intensity of the rays, and, consequently, the contrast between the field and the stellar image depends entirely on the angular aperture of the lens, and the larger this is correspondingly fainter stars come within its grasp for exposures of similar duration. Of course, if the exposure is suffi- ciently prolonged, a small lens would record as faint stars as the largest telescope, provided the light rays are of suflicient intensity to set up chemical action on the plate. Put briefly, the smallest class of lens, say, from li to 3 inches of aperture, is the most eflertive optical ap- pliance for the delineation of diffused nebulosities such as those in Taurus or Orion already referred to, while they are also well adapted for securing meteor trails. The ckiss of phenomena coming within the reach of lenses of from 3 to 6 inches aperture is verv much wider, and embraces well-defined nebulous areas, open clusters, regions of the Milky W'ay, stellar charts, comets, &-C. If only a single lens is available it should have as large a linear aperture as possible, and as large an angular aperture as is consistent with good defini- tion. For all solar, lunar, and planetary work, for crowded stellar clusters, for small nebula? and all well- defined objects of this class showing structure, re- 396 KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. course must be had to the telescope, which, as air, ail\ indicated, should for piirelv photographic purposes have an angular aperture of about f/4 or f/5. The size of the image on the plate will determine whether the focal length of the instrument shows the object on a s',:lTiciently large scale to bring out the detail aimed at. In presenting to the amateur the following hints re- garding apparatus and methods of working, it ought to be pointed out that these are for the most part merely- explanatory of the writer's own experiments, as he has never seen any photographic appliances used for astro- nomical purposes, other than those in his own pos.session. Satisfactory results can doubtless be ob- tained by other methods, and an ingenious amateur pos.sessed of a little mechanical skill will be able to con- struct appliances in the shape of accessories, or adapt those he may have already at hand, to meet his individual requirements. Mounting CameraLS and Lenses. To bring such lenses as those referred to into use they should be attached in the usual way to a suitable camera — preferably one of the old-fashioned box type, which secures the maximum amount of rigiditv. If the lens is not fitted with rack and pinion the body of the camera should be made in two portions so that one part may be slipped, telescope fashion, into the other. When the solar focus of the lens has been determined previous to mounting a movement of about half an inch will be quite ample. The camera should be firmly bolted to the top of the telescope tube opposite the Declination axis, a position which least disturbs the balance of the instrument, and where any slight irregu- larities in the driving are reduced to a minimum. With heavy lenses it is necessarv that the mount be rigidly supported, otherwise the effect of flexure may, when the exposure extends to several hours, be ap- parent in the shapes of the star discs. A method which is found to be very satisfactory in practice is to place over the mount a flexible steel spring or strap tightly stretched by a screw to the camera base, which is ex- tended below the lens for that purpo.se. The circular caps, with which lenses are usually fitted when .sent out by the makers, will be found with large apertures to be exceedingly awkward to manipu- late in the dark, and are otherwise unsatisfactorv. A simple arrangement, which leaves nothing to be desired, consists of a mahogany frame with shutter hinged to open like a door. If the hinges are placed at the side the shutter may be instantly clo.sed with a piece of string, but, on the whole, it is, perhaps, preferable to have the hinges below, and the shutter to open from the top. Fig. I shows a doublet lens of 5I inches aperture and 22 inches focus, mounted on a Newtonian reflector with the appliances referred to placed in position. It may be here incidentally pointed out that this is the only form of telescope which the writer has had in actual use in connection with photographic operations, and certain of the accessori,\s described and methods of using such are only applicable to this type of instru- ment. Having decided to give an exposure of, say, two or three hours, on a particular object, it will iiot infre- quently happen in this changeable climate of ours that before the desired limit has been reached operations may be stopped by cloud, and provision must con- sequently be made for completing the exposure on one or more subsequent dates. The risk of disturbing the position of the objects on the plate is thus considerablv nil iiased, and one of tlu- hki^i frequent sources of trouble in this respect is due to replacing the shutter of the dark slide. This may be obviated by attaching a stout bar to the back of the camera, and if two screws provided with cushions at the ends are pas.sed through this bar so as to press firmly against the dark slide, no movement of the plate can take place. This arrange- ment is shown in Fig. 2. Instances will occasionally arise where it is advan- tageous to have a number of short exposures of an object on the same plate. This is most easily done by mfning the dark slide, and, in order to serure uniformitv in making the necessary movement, a long screw (also shown in Fig. 2) may be attached to the side of the camera. The end of this screw presses against the slide, and by giving the requisite number of turns to suit the requirements of the object, a row of images is secured with exactly the same interval between each exposure, if a lens of long focus is used a very inter- esting .series of photographs might be taken in this manner during the progress of a solar or lunar eclipse. April, 1906 KNOWLEDGE & SCIENTIFIC NEWS. 397 Guiding Telescopes. In carrying on photographic work with lenses thus mounted the supporting telescope can always be used for guiding purposes, the best form of eye-piece being one of low power, fitted with cross wires sufficiently coarse to be readily seen on an out-of-focus image of a star. If the guiding telescope is of fairly large aper- ture, it will be found in practice that a star sufficiently bright can usually be found not very far from the centre of the field covered by the plate in the camera. The out-of-focus image of a faint star does not admit of being enlarged to the same extent as that of a bright one, and the cross wires should always be distinctly seen, otherwise guiding, particularly if the driving clock is not to be relied on, becomes a very tedious operation. The eye-piece should be turned until one of the cross wires exactly coincides with the path of a star across the field when the telescope is stationary, so that, apart from occasional slight alterations in De- clination to correct for \arying refraction, the move- ment of the telescope in Right Ascension will only have to be attended to, and any irregularity in the driving can be instantly corrected. Focussing. No difficulty need be experienced in adjusting the camera to the correct focus of the lens, if the sun be utilised for this purpose, and, when the position of the screen is such that the solar image is most sharply defined, this may for all practical purposes be accepted as the correct focus for all celestial objects. When the camera has been properly adjusted, and when this has been verified by a few exposures, the two portions of the box may be screwed together, as too much care cannot be exercised with the view of eliminating every possible source of movement which would be likely to disturb the register of the plate. If a screen of ground glass is used for focussing purposes it should be of the finest grade procurable. Perhaps a more suitable material is an ordinary gelatine plate, which has been exposed for a few seconds to a diffused light, and after- wards developed, fixed, and washed in the usual manner. Some have recommended a piece of plain glass with lines ruled upon it with a diamond. Defining Properties of Lenses. When the rirsl t.'\|j(isuri- lias been mack' a feeling of disappointment may be exjierienced when it is seen that tiif star discs are only sharply defined over a small central portion of the plate, while towards the edges they have the appearance of short circular trails. It must, however, be kept in view that the area of critical definiti(Mi with even the best portrait lenses, when used without diaphragms, is usually smaller than the working aperture, and if a 5 in. lens covers a quarter plate sharply up to the edges, it may be regarded as having excellent defining qualities. With the view of getting good definition over a larger portion of the plate some have suggested a method known as " averaging the focus," i.e., adjusting the focus to an object some distance from the centre of the screen. A few experi- ments carried out in this direction will, however, clearlv show th.il the method is not one to be recommended, as it will tlKMi be found that ihe fainter stars at the centre of the plate, instead of being minute points, are blurred and enlarged. This applies with even greater force to photographs taken at the primary focus of a mirror, as the least alteration of the distance .separating the speculum .and plate appreciably alters the definition of- the whole field. (To be continued. ) MoLgnetism acnd the Corona. Dr. Trowbridge's Experiments. In the course of an investigation made by Dr. John Trowbridge, and reported by him in the Americafi, Journal of Science, on the phenomena presented by electric discharges in strong magnetic fields, he found that with high voltages and strong, steady currents, phenomena began to appear which were absent at lower voltages and lesser currents. For the purposes of the experiments, the description of which we are about to recapitulate, Dr. Trowbridge employed com- paratively large tubes; and while the voltages ranged from 3,000 to 8,000 between the discharge ter- minals, the currents ranged from five milliamperes to twenty milliamperes. The cylindrical glass tubes con- taining rarefied air, which were used in the following ex- periments, were 30 centimetres long and four centi- metres in diameter; and for resistances E)r. Trowbridge made use of a column of running tap water. At pressures varying from i cm. to i m.m., the cathode light on a circular aluminium plate, forming the pole of a powerful magnet, the magnetic lines of which were directed along the line of electric discharge, was driven to the circumference of the disc, forming to the eye an apparently steady circular discharge. When the tube was covered, however, with black paper, so that only the light on the disc could be seen, if this light were examined in a revolving mirror, an interest- ing case of unipolar rotation was seen. Fig. i is a photograph taken of the reflection in the revolving mirror. The glass walls of the tulje through which the photo- graph was taken and the necessary obliquity in the re- flection caused by the mirror, modify the sharpness of the image. But the revolution of the image round the pole is apparent. The speed of revolution was found to increase with the degree of exhaustion of the rarefied air in the glass tube. IVcsumably when the free path of the ions increases, the progressive effect along the magnetic lines becomes more than the rotational effect of the magnetic field. When the plate formed the anode and also the end of a magnetic pole, so that the lines of magnetic force were directed along the line of electric discharge, the light at the anode was separated into two distinctly different lights, one (in rarefied air) 398 KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. a plume-like rosy lii^ht, the other a plume-like violet light. These discharg-es also revolved around the pole near the centre of the disc instead of on the circum- ference, as in the case of the cathode disc. On account of the number of individual discharges on the anode il was difficult to follow their motions in a revolving mirror, or by the eye, or to photograph them. It was ceitaiii, however, that they rcv(jivc-d about the pole. Dr. Trowbridge draws the following inferences from the experiments : — The unipolar rotation which 1 have described leads Fie. my mind to connect the phenomenon of coronal streamers seen at the poles of the sun in an eclipse with the effect of a magnetic field on possible electrical discharges between the equatorial regions of the sun and the poles of the sun. If we suppose that a differ- ence of electrical potential can arise between the swiftly moving strata of gases or from the eruptions which take place mainly along the equatorial belt and the polar regions, the supposed magnetic poles of the sun would undoubtedlv tend to cause the resulting electric dis- charges to revolve about the pole. On account of the Fig, 3, vast circumferential area about the poles a number of discharges could occur at different points around the pole and each discharge would revolve under the effect of the pole. In observing the effect of a strong mag- netic pole on plate terminals in wide tubes of rarefied air, at comparatively high pressure of air under condi- tions of high electromotive force and great current density, one can observe phenomena of rotation which cannot be photographed yet which present to the eye a strong analogy to the appearance of coronal streamers. I arranged a number of collections of bristles on a disc which was then set in rapid rotation. l*"ig. 2 is a photograph of the appearance of such revolving streamers, which represent fairlv well what may be seen at the terminal of a discharge tube in a magnetic field. There is, however, another magnetic phenomenon uiiich may have a bearing upon the coronal streamers at the poles of the sun. When the lines of magnetic force are at right angles, or transverse to the direction of the electric discharge, at comparatively high pres- sures, one to two centimetres, with currents from 5 to 20 centimetres, 3,000 to 8,000 volts in wide tube streamers radiate from the position of the magnetic pole. Fig. 3 is a photograph of such streamers or strati- lications. " It will be noted," says Dr. Trowbridge, "That these stria? make their appearance at a much higher pressure than that of the usual striae in rarefied gases." Similarly, electric discharges around or to- wards the poles of the sun, transverse to the lines of magnetic poles of the sun. could be separated into ".treamers. Mice a.nd Pnexjmonia.. Oh late years it has been confidently asserted by the bacteriologists that the domestic cat is the harbourer and the propagator of the germ influenza. .\n equally serious accusation is being made against the domestic mouse, which is said to be a probable disseminator of pneumonia. The bacillus which usually is held to pro- duce pneumonia is, in one form, that of the pneumo- coccus bacillus, very generally with us; and it has been sometimes assumed that the reason why it is a more successful enemy of the human race in the winter months — December, January, February, and March — is the smaller resistance which we offer to it in this season of reduced vitality. Tliat is a fairly sound hypothesis. Sir Lauder Brunton has shown, for example, that fowls, which are normally immune from pneumonia, can be made susceptible if they are kept standing long enough in cold water. But Dr. E. Palier, in the Xew York I\ledical Record, has another suggestion to offer. The common bacillus ol pneumonia, for which he proposes the name of " diplo-lanceo-bacilli-cocci," becomes viru- lent only, he maintains, when it has attained a new \ Itality by passing through the system of an animal extremely susceptible to it. Such an animal is found in the mouse, and especially in young mice, which are very readily susceptible, and to which the disease usually proves fatal. ITiese mice, which are especially plentiful in the winter months, and are more noticeable in the insides of houses, take up the pneumococcus of human beings, absorb it, and restore it in augmented numbers and more virulent form. In poorly ventilated rooms the virulent " d.l.b.c", as Dr. Palier shortly terms the characteristic bacillus emanating from in- fected mice or from their decomposing- bodies, become abundant. Dr. Palier claims for his theory that it appears a plausible explanation of the duration of pneu- monia. Virulent "d.l.b.c." do not lose their virulence at once, but after the third or fourth generation. \\'hen the virulent " d.l.b.c." enters the human bodv, some seven or nine days elapse before they are reduced to comparative harmlessness. It is possible that other animals besides mice may act as temporary hosts. April, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 399 Eolithi^ MaLi\. By W. A. DuTT. Just now, when the Eohthic controversy is sjeneratingf so much heat, and we are having-, to some extent, a repe- tition of the arg-uments used for and against the authen- ticity of Paia?oiithic implements some sixty years ag;o, it may be worth while to look a little further afield than the Kentish Chalk Plateau and sec how widely eoliths appear to be distributed over the surface of the earth, and what are the views of the chief authorities on these supposed implements of human fashioning- in respect to their relation to the question of the antiquity of man. That we are enabled to do this with slight difficulty we owe chiefly to iM. A. Ivutot, the Curator of the Brussels Royal Museum of Natural History, and one of the mostdiligentinvestigatorsof Eolithicproblems. As long ago as 1867, the Abbe Bourg-eois claimed to have discovered at Thenay (Loir et Cher), at the base of some freshwater beds, which are now referred to the Upper Oligocene. some flints which had been worked by human hands; and if the human fashioning- of these stones could be admitted they would furnish evidence of the earliest appearance of man on the earth which has yet been sugg-ested to us. On the subject of these Thenar flints, however, authorities disagree, and as recent researches in the locality have failed to reveal flints bearing any resemblance to those found by the Abbe Bourgeois, M. Rutot considers it advisable to leave the matter of Upper Oligocene man in suspense. About the flints of Puy-Courny, near Aurillac, however, he has no doubt, and in considering them the earliest genuine eoliths he has the support of M. G. de Mortillot, Dr. Capitan, and several German anthropolo- gists. These Puy-Courny flints were first found bv M. J. B. Ramcs, in an Upper Miocene deposit, and their chipping is said to be remarkably clean and character- istic. So far they are the strongest evidence of the existence of Miocene man. As M. Rutot remarks* : " This industry being the most ancient known and ad- mitted, it is to the Upper Miocene we must go for the first certain evidence of the existence of man." During the last two or three years a great number of eoliths have been met with in various localities of the Cantal Miocene, and a fine collection of them has been arranged and classified by M. Rutot for the Brussels Museum. Next in order of antiquity, M. Rulot places the flints of the Kentish Chalk Plateau, which he refers to the Middle Pliocene, and describes as implements intended to break, scr.'ipe, smooth, and pierce. Coming down to the Upper Pliocene, he claims as representing the eolithic industries of that period the flints discovered by the .'\bbe Bourgeois at St. Prest and those met with by Mr. Lewis Abbott in the Cromer Forest Bed. Geologists are uncertain, however, whether the implementifcrous gravels of St. Prest belong to the Tertiary or the Ouaternary period, ;ind there seems lo be a general opinion that it is safer to refer them to a period of transition between two dis- tinct epochs. This is also the case with the deposits of the Cromer Forest Bed. So far verv few supposed worked flints have been found in the l'"orest Bed; bul M. Rutot, to whom thcsi- were submitted bv Mr. Lewis Abbott, states that he h.-id no ditlicultv in recognising them as eoliths. The earliest Ouaternary deposits containing eoliths are, according to the same authority, met with in the • Bulletin of the Belgian Society of Geology, Pal.xontology, and Hydrology, Vol. XVII. (pp. 425-438.) valley of the Lys (Flanders), in the valleys of the Escaut, Haine, Sambre, and Meuse, and on the plateau of the Campine. These early Ouaternary implements are especially abundant around the village of Reutel, and M. Rutot has given the name of Reutelien to this particular eolithic industry. " Tlie use of the flints," he writes, " dates from the beginning of Ouaternary time, corresponding -with the phase of the advance of the first Ouaternary glacier." With the retreat of this glacier a new industrv was developed, examples of which arc found in the valleys of the Dendre, Haine, Sambre, and elsewhere. Tliis industry is considered lo be transitional between the Reutelien and a later one called Mesvinien, after a characteristic locality situated between Hyon-Ciply and Spiennes. Tliis last-named is also unmistakably eolithic; but in certain localities the beds containing it are overlaid by deposits supplying transitional forms between the eolithic and early Pala'olithic. The second transitional industry, which is known as that of Strepy, is naturally reckoned by M. Rutot as one of great interest and importance, as the localities in which it is met with not only provide im- plements in which eolithic forms are perfected, but also t)'pes which enable the archaeologist to understand the origin of the well-known almond-shaped implement of the Palaeolithic period. It may be mentioned in passing, that M. Rutot, after drawing attention to the fact that the primitive or eolithic period is characterised by an absolute stagna- tion— that is to say, the latest eolithic implements are no better nor worse fashioned than the earliest — ad- vances an ingenious theory to explain the sudden ad- vance in flint-working, noticeable in the period of transi- tion between the Eolithic and the Palaeolithic. This was due, he suggests, to a purely geological cause. In the Tertiary period, he says, an abundant supply of flints could be easily obtained by the men who had occasion to use them; but at the beginning of the Quaternary the flint beds were, to a large extent, covered bv fluviatile deposits. .'\s a result, men began to fight for the possession of the localities where flints could still be found, and this fighting led to the inven- tion of implements which could be used as weapons of war. In a paper printed in the Bulletin of the Brussels .Anthropological Society, the distinguished Belgian savant expresses a belief that the investigation of eolithic problems now in progress must, in course of time, have valuable results, and he instances the dis- coveries of stone implements by Dr. G. Schweinfurth in Upper Pilocene deposits, in the neighbourhood of Thebes, and of similar implements by Dr. Klaatsch, in beds containing" remains of the great marsupials (Diprotodon) of Queensland as evidence of the wide distribution of eoliths over the surface of the globe. The accompanying photographs of (lints of eolithic forms produced in the Cement bactory of Mantes must naturally arouse considerable doubt as to the human fashioning of many so-called eolithic implements : but it remains to be proved that natural causes can have eflected such flaking and chipping as is done in a cement factory. By the courtesy of the Secretary of the .\nthropologifal Institute we are able to reproduce the photographs made bv Dr. Hugo Obermaier, of Paris, of the flints of eolithic form which are ,-iccidentally produced in the process of makinET cement at Mantes, and Dr. Obermaier, in his paper, says : — " I know no eolithic type which has not its correlative at Mantes. .Specimens of large size are only absent because the l)igg,?r blocks and slabs are not put into the machine ; but there occur cores, flakes, scrapers, and borers — in a word all the eolithic types ; and the.se are partly of rudi- mentary execution like the ' utilised ' flints of the pre-palaso- 400 KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. April, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 401 lithic st.Tife, parti)' of very complete development. Even the remarkably perfect pieces which are occasionally found among' eoliths have their parallels at Mantes, where there occur scrapers, hollow scrapers {lames d encachcs), and borers, which recall the finished types of La Madeleine. Bulbs of percussion, secondary chipping, and the other so-called criteria of intentional workmanship are all represented in their turn ; and this is the more remarkable because the flint of Mantes is dry and hard of fracture. Were the softer Hint of Puy Courny, for example, placed in the machine, we might expect modifications which differ from those ap- pearing in the more refractory material obtained from the chalk. " The process of manufacturing eoliths at Mantes is a rapid one. Recent experiments have shown me that they can be produced after a few hours of the rotary motion in water. When the tub is emptied after the lapse of twenty- nine hours the condition of the flints suggests the following sequence of events. Those first affected assume eolithic forms and are subsequently rolled and worn ; at a later stage some of them are subjected to further shocks which give them the appearance of re-worked implements ; in this con- dition they would resemble later (re-worked) eoliths. In anv case it is demonstrated that the cement tubs of Mantes pro- duce eoliths which are astonishingly like those of geological formation. As I showed in my previous paper, the arrange- ment of the machine proves that the pseudo-eoliths are chipped, not by an\' part of the mechanism, but bv the shock and pressure of one flint against another. The rapid action of the water resembles that of the Rhone, Rhine, and other rivers when in flood, while smaller streams would be still more impetu^us. The pot-holes formed by rivers are known to every student of geology. Anyone who has ever studied the ancient gravels of the Seine or Somme and other rivers, will be readily convinced that their volume was once very different from that which we now see. To-day they can scarcely carry down pebbles of small size, but formerly they deposited strata of the coarsest gravel, containing rolled blocks exceeding a metre in diameter. .Ml this presupposes a torrential river-action such as no longer exists in these regions at the present day, but was experimentally repro- duced at Mantes." Few people could readily say which of all animals was the most conservative, but an article by Dr. E. H. Scllard in the Popular Science Monthly enables us to award the palm to the cockroach. No insects are more abundant as fo.ssils and none so widely distributed through the various formations as are the cockroaches. The domestic cockroach, as many of us are aware, has a predilection for the neighbourhood of the kitchen boiler. The reason for it is that throughout geological time it has delighted in moist places. TTiey are often found near the traces of streams; usually embedded among the remains of fossil ferns; and, indeed, persistent search among fossil leaves of land origin will hardlv ever fail to bring to light at least detached wings and perhaps bodies of prehistoric cockroaches. It is an approxi- mately coinpletc geological record, an almost undam- aged genealogical tree, which lends an especial interest to the cockroach family. Throughout their long exist- ence they have retained, as compared with other insects, a relatively generalised structure. Morpho- logically they have learnt nothing, and have forgotten nothing. There have been one or two changes in their strnrlure since Paheozoic days. Their heads became tlatleiicd; the upper part of theirchests, the first thoracic segment, became rounded in the carboniferous era. The wings also began to change in the time of the coal measures, and the modern cockroach shows an altera- tion of the wing dating from Permian days and develop- ing since. Hut except that the adventurous spirit and probably the fig-hting ability of the early days, as marked by stronger wings and bigger bodies, have decayed, the cockroach to-day is about exactly what it always has been. A Simple Gas-Lighter. By Charles E. Benh.am. The following simple device will be found very conveni- ent for gas lighting, especially where incandescent mantles are used. ,\ celluloid tube — the tube of a cycle pump is exactly the thing, and at the cycle shops there are always w'orn out pumps to be had for a few pence — is fixed vertically in a wooden socket. At the upper end is inserted, so as to line the upper part of the tube, a wooden rod covered with tinfoil and about six inches in length. The rod is surmounted by a metal ball, which rests on the top of the celluloid tube. From the ball a thin wire is led to a thick iron wire projecting from the wall to a point centrally over the gas chimney. This iron wire must be insulated from the wall by a vulcanite or glass support. A second iron wire, uninsulated, also pro- jects from the wall and terminates at a point about one- tenth of an inch from the first. A strip of celluloid — such as a photographic celluloid film with the gelatine removed — clasps the celluloid tube by means of two little strips of wood, glued to it P3} A Simple Gas- Lighter. as shown, and screwed together when the encircling film has been drawn tight round the tube. The film so forms a rubber which, when held by the wooden strips, can be passed up and down the celluloid tube. At every movement up and down of the rubber, sparks fly be- tween the terminals, and the gas lights instantly. The finger and thumb should nip the rublx.'r in the centre so that it presses close to the tube. The arrangement is not materially affected by atmospheric conditions. A curious feature of the device, and one which at first sight appears to be unorthodox, is the circumstance that tlic rubber and the electric to be excited are both of the same material, instead of being of differeiit materials as is usually the case with friction machines." A rubber of flannel or silk may, however, be used instead of the celluloid film. The moiuilod celluloid tube can be aflixed either \erticallv on a shelf below the gas bracket or projecting horizontally from the wall, as may be the more conveni- <'nt arrangement. ■|"he terminals should not be pointed, but shoidd be formed by loops at the ends of the thick wires, which are to be adjusted so that the spark is about an inch above the top of the gas chimney. The tube should prrferablv Ije of vi-hite celluloid. I'sing a larger cellu- loid tube a Geissler tube may be beautifully illuminated by connecting it with the brass ball. 402 KNOWLEDGE & SCIENTIFIC NEWS. [Al'RIL, 1906. The ColorsLtion of MaLmimacls OLiid Birds. By J. Lewis Honhote, M.A., F.L.S., F.Z.S., M.B.O.U., &c. (('i)ntinin'd from page 373.) So far, our remarks have been restricted to those " poecilomeres " which were first to be noticed as " centres of bleaching " in Ratufa, but a closer ex- amination will show that, in addition to those already mpiitloncd, sevcr.-il other spots are to be noted. Although in the present state of our knowledge we cannot show these to be actually " bleaching centres " in any particular species, yet they correspond so closely ivith those " poecilomeres " already mentioned that there can be no doubt that they arise in q similar manner. The complete list of " poecilomeres " is, therefore, as follows : — On the head, we have the nose, lips, chin, crown, occiput, ears, and the eye. This last has, in reality, two spots, the one in front of and above the eye (supra- orbital), and the other below and behind it (post- orbital). 'J'lu- wliile-earcd cob {('obns maria) gives us a good example of the eye spots. On the upper pari of ihc body we have the shoulders, thighs, rump, tip of the tail, wrists, and ankles. The under parts are, as a rule, more uniform in colour, but where any tendency to diversity is shown we find it taking place along fixed lines, and the following spots may be noted as " poecilomeres, viz., the chin, inside of the arms and legs, fore-end of the sternum, and the vent or pubic regions. The best example of underside " poecilomeres " is to be found in a squirrel of South America (S. dorsalis), which is, as a rule, ochreous underneath, but shows in many individuals permanent white patches on most of the spots. In 5. prveri, a Chinese squirrel, the armpits and inside of the thighs and vent are rufous, while the rest of the underparts of the body are white. .'\mong birds the white ring of the ring ousel, the white breast of the female frig;ite bird, the red breast of the shell-duck, the violet patch of the jambu fruit pigeon, and the red patch of the blood-breasted pigeon, are good examples of the sternal " poecilomerc. " The red vent of the woodpecker and white \cnt of the moorhen are examples of another patch. As regards the face markings among birtis, the common kingfisher affords a good example, showing us the white chin patch, the green malar stripe, corre- sponding to the lower lip in mammals, the dark mandi- bular stripe, the rufous supraorbital and postorbital, and white oral patch. To continue multiplying in- stances of the.se spots is unnecessary. Anyone inter- ested in the subject has only to go through any collec- tion of birds or mammals to find instances on all sides. It has been further pointed out to me, and is, per- haps, not without its significance, that the spots in which hair is found in man are all to be found among these "poecilomeres." Unfortunately I am not a physiologist, nor have I been able to find in any book' facts which would tend * lam not unmindful of Captain Barrett-Hamilton's paper (already referred to) where he is inchned to consider the white patches to be due either to the presence of subcutaneous fat or to the direct contact of bone with skin, but for the present I prefer to express no definite opinion on this point. Mr. Tylor lias also some suggestive ideas on lliis point. to throw light on the nutrition or otherwise of these particular spots, but there is little doubt that any practical physiologist, who could afford the time, might, by investigations carried on in this direction, add a considerable amount tO' our knowledge of the cause of the patterns and markings in animals. Most of the warning and protective markings will be found situated on these " poecilomeres," but there is one point which I would wish to impress, namely, that these same markings will be found in hundreds of cases, where, unless they were looked for, they would pass imno'liccd, being merely represented by differences in shade so' slight that they cannot possibly be said to serve any piuposes of protection, warning, or recogni- tion, but, in my opinion, form additional evidence to show that the brighter and more conspicuous markings have a much deeper significanre than th;it put forward by those who^ believe the theory of n.itural sclrrtion to be all sufficient. As examples of this, I will notice two or three from among our local British birds. In the hen hou.sc sparrow, for instance, the rump is unspotted; the rump of the hen chaffinch is slightly greener than the rest of the back; the hen yellow-hammer shows the dark car patch and light malar stripe and chin. The linnet shows the two eye patches. The young cuckoo will often show a few white feathers on the occiput or crown. The wryneck (Jtinx torquilld) shows f.aintly the beginnings of the chin or malar stripe in having the feathers of those parts, although resembling the rest in pattern, white instead of yellow, while the dark patch in front of the barn owl's eye and the yellowish tinge on the breast are further evidence that the small- est of these markings is no mere sport or accident, but the result of deep-seated physiological causes. Among our British mammals the white spot on the forehead sometimes found in the common hare may also be ac- counted for on the s.ame lines of reasoning. " Poecilomeres " also manifest themselves in some species in a transitory state. The stoat offers a good example, for when it commences to assume its white winter dress it does so along well-defined lines. The first spots to show white are the thighs, whence the white spreads down the hind limbs and along the sides, gradually encroaching more and more on the colour of the back. It then appears on the rump and shoulders, spreading down the tail from the former, and down the forelimbs and over the shoulders from the latter. The head remains coloured to the last, but when it begins to change, the lips, no.se, and ears are the first to whiten, the white from the nose extending up between the eyes as far as the forehead, thus leaving the eyes, postorbital patch, and frontal patch the last to turn. In a lesser degree this may be observed in many mammals ; the common hare, for instance, showing a tendency to lighten on the thighs on the approach of winter. Among birds the following example has come under my notice recently, and, with further observation, doubtless instances might he indefinitely multi- plied. During the past winter I have had under ob- servation two young shovellers [Spatula clypcata) that, during the early months of the year, have been slowly assuming the metallic-coloured head of the adult. Both birds performed this process in the same manner. The first sign of the metallic plumage was observed on the postorbital and ear patclies simultaneously; these two patches spread and joined together forming a metallic patch similar in range and definition to that found permanently in the m.alc teal. The patch of April, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 403 adult colour then spread across the head till the whole of the head with the exception of a patch across the front was deeply coloured, the bird now having its head marked similarly to the hen scaup {Fiiligula marila). The final stage was completed by the colour spreading backwards from the beak to join the metallic colours that already existed. This case is important for several reasons. Firstly from its analogy with the case of the stoat, where, although the reverse change was in process, yet the parts that in the shoveller were the first to become coloured were in the stoat the last to become white " Secondly, to find processes, whose outward effects are so transitory that they can be of no' importance to the individual, practically identical in two animals as widely separated as a carnivorous mammal and an aquatic bird can only {Xjint to one conclusion, viz., that they must have some deep meaning in the internal economy of mammals and birds far transcending their external effect. Another point to be noticed is that during the change the birds assumed the more or less characteristic mark- ings of two other species of duck, thus hinting at the probable way in which such markings arose, and, lastly, the assumption of colour on the lines of the " poccilomeres," beginning with the postorbital and ear, and these two joining together and subsequently covering the crown and occiput, while, finally, instead of the colour gradually spreading forwards it started again from near the beak, that is to say on the lip and nose " poccilomeres," whence it covered the head, this, I think, shows that these "poccilomeres" have very real and definite areas, and that although the col- our arising from one " poecilomere " may spread into an area usually fed, so to speak, from another one, yet these " poccilomeres " will always be the first or last patches to be affected. It may perhaps be said that the above example is a solitary instance and mere coincidence, but this is not so. The hen tufted duck yearly assumes for a short time during the summer tlie white patch character- istic of the scaup. The blackhcaded gull assumes during the early months of the year the brown hood in a very similar manner. The two eye and ear patches show first; these at first tend to join across the head with the crown and occipital patches, forming two dark trans- verse crescents until, finally, the back of the head Ije- comes brown, leaving the frontal patch the last to become coloured. A herring gull, when assuming the white head of summer, becomes white round the beak first of all, and when in the brown plumage of im- maturity will first show signs of the white breast on the sternal [jatch. The bfack throat of the lapwing (Viincllus), W(jrn in sunnner, first appears on the chin immediately behind the lower mandible, and gradually spreads over the neck until it joins the black collar, and in many cases in young birds, e.g., the corncrake [Crcx), the feathers composing the ear patch are the first to grow. Lastly I have known a brambling {F. moniifringilla) that, in assuming its black head by abrasion of the feather tips, first lost the brown tips of those leathers round the beak that formed the frontal patch before referred to. This forms additional e\ idence that abrasion takes place on lines similar to those con- • I am now able to add a third precisely similar method of change m the assumption of the ecHpse plumage in a smew (see AvkiiU Mag., Feb., 1905.) trolling " bleaching," and that it is a process governed by internal conditions. This paper deals with a subject of such vast propor- tions and is dependent on so many minute details that it may be well to sum up the results and arguments in a concise form. SUMMARY. Th(? oljject of this paper has been to show, firstly, that the colour of a bird or mammal is primarily due tO' " activity of nutrition and function," which has been calletl " vigour," and that where conditions lor a high state of " vigour " exist we shall find the majority of animals brightly coloured and vice versa. " \'igour " is dependent on two causes. (i.) Climate, which contains two factors: — (a.) Temperature. {b.) Food. (2.) Rise and fall of sexual activity. In Polar Regions, where the two causes coincide closely, the changes are much more marked and \ iolent. In Temperate Regions, where the climate is suffici- ently severe to affect the " vigour," but where, at the same time, there is a sufficiently long period of com- parative plenty to prevent the sexual acti\ity clashing with climate, the changes are less marked. In Tropical Regions the first cause is practically re- moved, and any changes in colour are due to sexual causes, except in cases of temperate species which have spread into the south. Now the individual " vigour " of various species and groups will differ, and one animal may be able to main- tain a full vigour under conditions which would be impossible to another. This will account for animals, although Polar, becoming brightly coloured, e.g., musk ox, raven, penguin, &c. It follows, therefore, that if they can maintain a full " vigour " in colder regions, they can either (i) maintain an equally full \igour in the tropics, or (2) in hotter climates their metabolism would become too active and they would die. Con- sec|uently, a dark-coloured animal, in Polar regions, must either be confined to Polar regions or be cosmo- politan, e.g., musk ox, raven. By a similar process of reasoning, bright-coloured tropical animals will be found extending northwards, probably becoming lighter, \\ hile white or light coloured tropical animals will be confined to the tropics, e.g., tiger, and Rhisomys snmatreiisis, the bamboo rat. Seasonal change or migration is a necessity in Polar regions, and birds which migrate to the tropics assume much more g.uidy colours while in hot climates, be- coming dull when the moult takes place mi the Arctic regions, e.g., knot (I'riiiga). In temperate regions seasonal change will be a con- stant feature, but the changes will not be so marked, e.g., squirrel, deer, but when these animals reach torrid zones, the " seasonal change " will tend to persist for some time, gradually disappearing, or it may become a " breeding change," as .^eiiiriis caniceps, Cervus cidi. There is among mammals and birds a process known as " bleaching "; this, I attempt to show, is an active process, and not mere action of wind and weather. I further show that bleaching always takes place along certain lines, starting and spreading in various degrees from certain centres, e.g., lips, eyes, ears, crown of the head, occiput, shoulders, thighs, fore end of the sternum, vent, tip of tail. To these centres or spots the name " Poccilomeres " (spotted part) is given. The second part of the paper is devoted to showing how these " poccilomeres " exist as either white or 404 KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. deeply-coloured patches throughout the majority of species of mammals and birds, sometimes as large and conspicuous patches, e.g., hindquarters of the rabbit, rump of bullfinch, and at other times only distinguished from the surroundmg parts by differences of shade so slight as to be incapable of serving any warning, pro- tective, or other similar purpose. It is then pointed out that in some cases the " poeci- lomeres " are only visible as transitory patches during the time an animal is undergoing a change of colour. The head of the stoat and of a young shoveller drake are cited amongst others as examples of the change taking place along precisely similar lines, whence it is argued that as the outward effect is so slight and transi- tory, and as the process exists in two ;uiimals so widely separated, the fundamental cause must be a deep- seated physiological one. We, therefore, claim to have shown that where con- ditions for high vigour exist the majority of the animals will be brightly coloured, and suggestions are made to account for the apparent exceptions to the rule, wliich suggestions aie borne out by the distribution of the dark I'olar and light tropical species. We have also shown that shortly before a moult, in many animals, the colour of the pelage fade.s, beginning along certain definite areas, and from certain centres which I have called " poecilomeres," and that this bleaching is due to physiological causes. Further, that " poecilomeres " may be found throughout the mammalian and avian series, as patches differing either in their intensity or lack of colour from the surrounding portions, in many cases conspicuous, and cited as examples of warning, protection, Sec, or, again, as marks so slight as to be unnoticeable unless carefully looked for, or yet again, merely appearing as transitory patches during the growth of a new pelage or plumage. Hence it is argued that these patches, so universal, and in many cases so inconspicuous, must owe their inception to internal rather than external causes, and that we have here the basis of diversity of colour in coloration. If these facts then be accepted, both colour and coloration must be due to physio- logical causes. The question of whether seasonal changes are pro- duced by moult or by colour has purposely been en- tirely omitted as belonging to a side issue. Natural selection and protective coloration have also been left out, not because we do not believe in the great part they play, but because, if our suggestion be near the truth, they are only able tO' make use of those colours or modify those markings which in the first place are supplied by " vigour." Tuition by Correspondence. The University Examination Postal Institution of 27, South- ampton Street, Strand, publishes a series of handbooks which are specially and excellently adapted for Cambridge Higher Local Candidates. The series includes a guide to this examination, giving full details as to method of pre- paration, and advice as to text books, together with reprints of papers set at previous examinations. .As each paper is printed en a separate perforated sheet, it can be used by schools for examination purposes. The papers are kept up- to-date by the insertion once a year of the latest papers. To the French and arithmetic papers full answers by F. Thomas. B..\., B.Sc, and W. H. Dines, B.A., F.R.S., are published in addition to the questions. Both the method and the subject matter of this valuable little series of handbooks are well arranged, and we can confidently recommend thein to the perusal of candidates and students. PhotogrsLpKy. Pure and Applied. By Ch.^pman Jones, F.I.C, F.C.S., &€. Uncorrected Lenses. — A week or two ago, the Fhoto- Club, of Paris, opened, in their rooms, an exhibition of photographs made by means of lenses uncorrected or only partially corrected for chromatic aberration, and it appears that in due time a collection of these prints will he shown in London by the Royal Photographic Society. Uncorrected lenses have been used, and used purposely on account of the character of the image that they give, for long enough, but the lenses that this collection illustrates the use .of, have been recently de- signed by MM. L. de Pulligny, and C. Puyo, and are issued commercially by L. Turillon, of Paris, under the name of " Anachromatic " lenses. Thev may be em- ployed in the form of single lenses, symmetrical doublets, or with a negative lens behind a positive, as in lelephotographic combinations. So far as can be gathered, it appears that the effects of chromatic aber- ration are specifically valued, as giving- what a perfect lens would render as a sharp line, in the form of a diffused line that is darkest down its centre and gradually becomes lighter as the distance from the core increases. In this way, detail is softened and fine detail is averaged down to a comparatively level tone. These desiderata will be appreciated by many artists who photograph only for the purpose of making " pictures." Of course, such lenses must be of greater focal length for a given plate than the modern anastig- mat or even its predecessors need to be, because of iheir inferior covering power. The aim of the optician is to improve definition and increase covering power, and quite rightly so, but if the pictorial worker does not want these improvements, he is a positive loser in hav- ing instruments that possess them. It is the photo- grapher's ignorance of optical matters that leads him to imagine that the more costly a lens, the better it should serve his purpose. Whether it will do so or not depends entirely on what his purpose is, and wherein the special value of the lens consists. The greater focal length is generally a distinct advantage in pictorial work, and granting this, the need for costly lens systems does not exist, even when fully corrected lenses are required. Complete descriptions of the " .\nachro- matic " lenses are not to hand, and therefore the novelty of their construction, if they are in any way novel, can- not be now given. Improvements in " Cooke ^' Lenses. — Mr. H. Dennis Taylor, of York, the inventor of the " Cooke " lenses that are so well-known to photographers, is still seek- ing to improve them and increase their usefulness. The three single lenses that constitute the ordinary Cooke objective cannot be separated into two complete parts of greater focal length like so many modern lenses that thus give in one instrument the choice of two, or, if not symmetrical, three focal lengths. Mr. Taylor has devised a means of obtaining this advantage bv duplicating the usual system of three lenses, making April, 1906 j KNOWLEDGE & SCIENTIFIC NEWS. 405 such modifications as the new arrangement requires. The diaphragm has, of course, to be between the two systems, and to maintain the aperture for oblique rays the exterior lenses are shghtly enlarged and brought nearer to the others. In such a complete objective the light has to pass througli twelve surfaces of glass in contact with air. And in a modification described, in which there are eight separate lenses, there are sixteen such surfaces. At every surface of glass to air there is a loss of light due to reflection, and Mr. Taylor esti- mates this at about forty-eight per cent, of the incident light, when there are twelve glass surfaces. A part of this light is altogether lost, passing out of the lens in front, but a part goes in the other direction and con- tributes to the general useless light in the camera, which of course, tends to produce fog on the plate. Mr. Taylor seeks to remedy this defect and secure greater brilliancy of image, by tarnishing the polished surfaces of the lenses, using a solution of sulphuretted hydrogen, for example, until they assume a brownish-slate colour by reflection. He thus claims to get a rather more brilliant image with six or even eight lenses than with only three lenses normally polished. It is quite easy to understand how that such a procedure will reduce the amount of reflected light, but it is not so easy to see how it increases the image-forming transmitted light. It appears at first sight that the tarnishing will reduce both the reflected and the transmitted light because of its absorbing power, but Mr. Dennis Taylor is such an experienced and expert technical optician that, presum- ably, there is some fault in this simple view of the matter. It may be noted that these improvements in Cooke lenses are not yet practically available. Clearing Intensified Negatives. — The character of the gradation of a negative is, or ought to be, one of its most valuable properties, and, as I have often said befoi-c, there is only one method of intensification that has been shown to preserve it, namely, the mercury and ferrous oxalate method. All the more usual processes and a great number of those suggested i>ut rarely used, have been definitely shown to be uncertain and un- proportional in their effects, and therefore to alter the gradation in uncontrollable ways. A minor drawback to the u.se of an oxalate when only hard water is avail- able is the precipitation of calcium oxalate, some of which may attach itself to the surface of the gelatine. If kept clean, it disappears entirely on varnishing and is quite inert, but it may, if desired, be removed by merely placing the negative in weak hydrochloric acid until it has been dissolved away. The strength of the acid seems to matter very little; perhaps strong acid, with ten times its bulk of water, is a good average. The time required may vary up to a few minutes.' I have seen celluloid films and plates of various kinds treated in this way with invruiable success, and have not heard of any failure or accident. The risk of frilling seems to be practically negligible. Therefore there are three distinct ways of obviating the difficulty resulting from such a deposit :— (,.)_It may bo prevented bv the use of soft water before and after the application of the oxalate. (2.)— It may be removed bv means of hydro- chloric acid. (3.)— It ni;iy be ncgkTfed if the negative is to be varnished. E. A. Wilson. — We do not know of anv more recent book on tlin (Iftoriniiialii)n of longitude bv pholiigrapliic mp;uis than thr oiu- vuu iiuntioii. ASTR.ONOMICAL. By Charles P. Butler, A.R.C.Sc. (Lend.), F.R.P.S. Determination of Radial Motions by Objective Prisms. Director E. C. Pick!;ring has just issued a further circular (Xo. 110) dealing with the method adopted at the Harvard College Observatory for the determination of stellar motions in the line of sight. The photographs are obtained with the Draper Memorial telescopes used as prismatic cameras, with large objective prisms placed outside the object glasses. .\ photograph of all the stellar spectra included in the ree'ion covered by one plate having been obtained, the objective prism is then turned through 1800, and then a second ex- posure on the stellar spectra is given on the same 'plate. It is not necessary or advisable to use two plates, as was formerly recommended. When, owing to special circum- stances it is more convenient to reverse the telescope, instead of turning the prism, the plate must in such cases be turned iSoo._ The corresponding spectra of each star in the two positions may be brought end to end, or in any desired order, by adjustment with a cross-wired eye-piece'. If the method were perfect it would only be necessar\- then to measure the distance apart of the" corresponding lines of each pair of spectra, and each star whose radial motion was known would serve to determine the constant distance apart of the lines ; the differences in distance, converted into wave- lengths, would then give the required motion of the other stars. .Since the motions of the sun and earth are the same for all, these will be eliminated. The princii)al sources of error, such as those due to the distortion of the lens, and temperature corrections, are radial, and may be determined by using both co-ordinates of the lines in all the spectra. .Any changes in the differ- ential refraction may be reduced by turning the prism so that the spectra become horizontal instead of vertical. To illustrate the method a sample plate of the Pleiades group is given. On the scale of the spectra given bv the 1 i-inch Draper telescope the probable error in the determina- tion of the motion would be + 3.5 km. In another series obtained with the 8-inch Draper telescope, covering loo square, the dispersion is about one-third of the former series, but as the scale is also about one-third, the definition is considerably better, and measures on these may have nearlv the same degree of precision. Much fainter stars are shown OTi the latter plates, lines being clearly defined in stars of Ihu eighth magnitude. The Coming Total Solar Eclipse, Ja-nuary 13 14. 1907. Of the six total eclipses which arc computed to occur diiring the next six years, that of 1907 seems least uncer- tain to yield signilic.ant results, and in anticipation of this the local particulars for various st.ilions on the track of that eclipse have bi'cn communicated to the Amvrkan Journal of Sciciiir by D. Todd and R. H. Baker. Following the eclip.se of 1905, August 30, bv an interval of seventeen months, the figure and "type of the corona will doubtless have changed considerably, so that it is of the highest imiHirtance to photograjih the solar surroundings at this opportunity. Fortunately the track is wholly on land, but a great part of the region is so remote and "difficult of access, being in .Mongolia and the Gobi Desert, that it could be occupied only by equipping tedious and expensive < xpiditions. The western half of the eclipse track, however, traverses 4o6 KNOWLEDGE & SCIENTIFIC NEWS. [Apkil, igo6. Turkestan, a trans-Caspian area penetrated by the Imperial railwa3's of Russia, and, for travejlers from the West, can be readily reached by way of Naples, Constantinople, Black Sea, Tiflis, Caspian Sea, Bokhara and Samarkand, or the alternative route via Berlin, Warsaw, Moscow, Samara, Orenburij, and Tashkent. On this railway about two- thirds the way from 'I'ashkent to Samarkand lies Jizak, which is only a few miles to the south of the ecli])se central line. Other easily accessible stations near Jizak, are Name of Stalion. Miles from Cen- tral Lati- tude North. Longi- tude East from Totality Begins. Totality Ends. Dura- tion of To- tality. Sun's Alti- tude. Line. G'wich. '0 / 0 0 , Local Mean Time. Turkestan— H. .M. S. H. M, 5. M. S. Chimbai 'lb. 42 ■ib 59 49 21 19 0-8 21 20 45-1 I 44-3 14 47 Jlzak .. 13-.. 40 8 67 48 21 59 58-4 22 J 55-2 I 56 8 21 34 i,S. M ■ib 68 26 22 3 19'5 22 5 177 I 58-2 22 4 Ira-tiube .. W M 69 0 22 6 371 22 8 409 2 V8 22 21 Nau 14 N. 40 8 69 22 22 9 105 22 11 5'i I 54 b 22 29 Sanku.. :2s. 39 15 71 13 22 18 496 22 20 58 0 2 8-4 24 9 East Turkestan— Tagharma Peak sS. ss 1-> 74 32: 22 39 "O'S 22 41 l8'2 2 7-9 26 27 Posgam 8S. 18 !.■> 77 19 22 54 2f4 2Z 56 39-2 2 178 27 50 Yarkand 4N. 18 2'i 77 21 22 54 374 22 56 54-5 2 171 27 41 — 3N. 18 12 79 54: 21 10 1"0 23 12 2I-0 2 20-0 Chcrchen .. -,b. 18 2 85 -33] 21 44 50-8 23 47 >2-6 2 21-8 3= 14 Mongolia- Tsair-osu . . 2N. 44 43 .06 41 : 49 416 I 51 367 I 15-1 19 23 Zaamin, Nau, and Ura-tiube, all well within the belt of totality. In order to indicate the exact circumstances of the eclipse throughout the length of its track, the local particulars have been calculated for the eleven stations shown .above, and an e.xtra possible station between Yarkand and Cherchen in- cluded from the British Nautical Almanac. Stars Having Pec\iliar Spectra. .'\ further li.-,t of stars showing special features in their spectra have been detected by Sirs. Fleming during her examination of the Henry Draper Memorial photographs of stellar spectra obtained with the prismatic cameras. R. Cygni. — A photograph of this variable star, taken with the 8-inch Draper telescope on November 19, 1890, shows the spectrum of this star to be class Md (Harvard Notation), having the hydrogen lines H7 and H5 bright. On a later photograph obtained with the same instrument on Decem- ber 7, 1904, the spectrum of this star appears to be of the fourth ty[ic, resembling class Na, and shows no trace of bright hydrogen lines. D.M. + 21" i5og. — R.A. = yh. 23.3m.; Decl. + 21° 7' (190°). — This object is in N.G.C. 2392, or identical with it. N.G.C. 2392 was found to have a continuous spectrum, with three bright lines, by Winlock and Peirce, on January 7, 1869, and was later found to be gaseous by d 'Arrest. Photo- graphs obtained with the 8-inch Draper telescope on Novem- ber 21, 1900, and November 27, 1905, show no trace of the bright lines characteristic of gaseous nebula;, but that the spectrum is of the fourth type. The images of the object on chart plates, however, are hazy, and the image on a photograph obtained with the Bruce telescope on April 16, 1904, shows distinct nebulosity, especially on the preceding and southern edges. D.M. -|- 36° 3907. — K.A. = 2oh. 5.8m. ; Decl.= + 360 ^i' (1900) magnitude = 5.5. The spectrum of this star in Cygnus was obtained on plates taken with the ii-inch Draper telescope on July 4 and November 4, 1905, and shows the hydrogen line H S as a fine bright line centrally super- posed un the dark line Hi. Device for Developing Corona Photographs One of the great dilVnullies encountered in ijhotographing the solar corona during total solar eclipses is caused by the very great range in intensity of the object; in most cases it is necessary to e.\po«- many different plates for carefully arranged times of graduated duration, so that we may ob- tain records of all parts, from the intense inner corona to the delicate tracery of the outer streamers. If a photograph exposed for any considerable time is developed normally the inner corona is generally so dense by the time the outer details are brought out that it is unprintable. Numerous suggestions have been brought forward for getting over this difficulty, the most successful hitherto being that of Burckhalter, who arranged a car lly calcu- lated series of rotating screens over his photographic plates during expostirc, so that the outer regions received more than the inner parts. These were partly successful in that all parts of the corona could be obtained of printing density on the same negative, but the artificial lines produced by the occulting screens were objectionable. Recently a method has been proposed by Mr. T. Thorpe, which ap- pears to give promise of success. Instead of developing the negative in the ordinary way, it may be mounted on a turntable, and centred so that the centre of the corona is coincident with the axis of rotation. Then by means of a small funnel or pipette mounted on a radial arm also work- ing on the same centre as the plate, begin the development by allowing the developer to fall near the edges of the plate ; afterwards gradually approach the stream of developer from the funnel towards the centre, restraining the developer also if found necessary, as it approaches the over-exposed parts of the inner corona. The centrifugal action due to the rotation of the photographic plate will, of course, prevent any of the developer getting nearer the centre than is de- sired. BOTANICAL. By G. Massee. The Periodicity of Sexual Cells in Dictyota Dichotoma. DicTYorA is one of the red seaweeds not tmcommon on our shores. In common with other members of the group, three kinds of plants possessing different functions concerned with reproduction are present. One set of plants produce antherozciids, or male fertilising bodies ; a second batch pro- duce oogonia, or female organs of reproduction ; while a third lot of planis produce tetraspores, or asexual reproduc- tive bodies. The antherozoids, which are motile or possessed of spontaneous movement, and the oogonia are respectively liberated at maturity into the water, when the antheroids approach and fertilise the oogonia. Professor Lloyd \Villiams describes in The Annah of Botany the important discovery that this liberation of the sexual organs is periodic. Several crops succeed each other during the summer months, and each crop from the period of its initiation, maturition, and discharge, occupies a fortnight. This periodicity is found to synchronise with the spring tides, and is expressed by the author as follows : — " So intimate is the relation between the tides and the crops of special cells, that a study of the tidal almanac for any locality will enable us to predict the actual days during- .August and September in any given year on which general liberation and fertilisation of gametes will occur, and even should exceptional conditions prevail, the resulting error will only be about a day earlier or later than the one pre- dicted." Several factors are more or less concerned in promoting this periodicity, .among which are variations in the degree of aeration and of pressure; also differences of temperature and illumination ; but the most important stimulus which favours the fortnightly development and liberation of a crop of anthcridia and oogonia is the periodic change in the amount of light, as a direct result of the alternation of neap and spring tides. Plants collected in October and kept growing for several nuinths in a laboratory showed periodicity in the liberation of their sexual organs, and behaved in every way in exactly the same manner as if they had been in the sea. This evidence is considered to indicate that periodicity is a heriditary character. No periodicity is manifested by those plants bearing tetraspores or asexually-produced reproductive bodies. Dispersal of Seeds a.nd its Bearing on the Geographical Distribution of Plants. Dr. Ridley, ot the Bont.iiiic tjardens, Singapore, has been studying the rate of dispersal of seeds by wind. They are April, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 407 grouped under three heads — winged fruits and seeds ; plumed fr ^'^ and seeds; " powder seed," or dust-lil^e, as orchid .seed,'" tern spores, &c. Winged seeds or fruit is dis- persed at the slowest rate, and is unable to cross a wide expanse of sea ; the plumed type is well adapted for rapid transit over open country, but is checked by forest areas, whereas " powder-seed " is dispersed most rapidly and to the greatest distance. The greatest observed distance travelled by the winged fruit of a forest tree, tihorea leprvsula, was 100 \ards. From this it is calculated that this plant could, under the most favourable circumstances, only spread 300 yards in lou years, and that it would take one and a half million years to spread from the Malay Peninsula to the Philippines, supposing a land connection existed. Smvit. Smut is the name used by farmers and gardeners to designate certain kinds of fungi belonging to the genus Ustilaqu, which form black powdery masses in the ears of oats, barley, wheat, and various other grasses ; also in the anthers of some flowers, as Scilla, Lychnis, &c. In the case of oats infection can only be effected when the plant is in the youngest seedling stage. The fungus spores are dis- persed by wind, and retain their vitality until the following spring, when they germinate on any decaying vegetable matter present in the soil, usually manure ; the germ-tubes pierce the delicate tissue of the oat plant immediately after gerniin.ition. After infection the mycelioma of the fungus grows up along with the oat plant, without producing any injurious effect, until the flowering stage, when the fungus enters the ovary and produces a black sooty mass of spores in place of the fruit. Maize, or Indian corn, it has for some time been known, can be infected at any point where very young tissue is present, but with this exception it has up to the present been considered that all other cereals could only be infected during the seedling stage, as described for the oat. Brefeld, a German botanist well-known for his many and important contributions towards the life-history of fungi, has recently been studying the smuts attacking cereals, and has proved by experiments that the smut spores of barley and wheat can only infect the plant through the flower. The spores alight on the stigma, where they germinate and penetrate the ovule, remaining there until the following season. When such infected seed is sown, the fungus grows up along with the plant, and eventually produces smut in place of grain in the ear. In some instances the fungus spores are dispersed by wind, in others they are carried to the stigmas along with pollen by butterflies. In the case of aquatic grasses, the fungus spores are conveyed bv water. This discovery adds wheat and barley to the already con- siderable number of economic plants of primary importance, whose most destructive enemy in the form of a parasitic fungus, can be conveyed from one district or one country to another in the form of mycelium present in the seed, tuber, bulb, &c. In this condition detection is impossible, and the danger of introducing disease into a new district consider- ably augmented. Mosses as Storers of Water. ExperimcnK conducted by .\. Csriiy show lli.it some abundant kinds of mosses, as llypniLm, IJiiranum, Sphaiinum, &c., absorb about six times thtMr own weight of water in less than a minute, and require seven days wherein to give it all up again. This function is probably of much service on st'-ep slopes, where an excessive rainfall if not checked would prove very destructive, and, further, by slow liberation of water the humidity of the air is, to some extent, secured. CHEMICAL. By C. AiNswouin Mltciikll, li.A. (Oxon.), F.I.C. A Physiological Test for Copper. I !■ lia-- Inqucnlly been noticeil llial the lra\es of plants that have been treated with a solution of copper sulphate show abnormal deposits of starch. This is evidently due to the poisonous action of the metal upon the enzyme diastase, which converts the starch of the plant cells into sugar, and it has been found by Herr Ewert that a minute trace of copper sulphate (o.ooo(;o5i gramme) is sufficient to produce this paralysing effect upon diastase left in contact with a very dilute solution of starch. On this fact he has based a very delicate physiological test for traces of copper. A plant watered with a dilute solution of copper sulphate at once begins to deposit the starch, and the latter can easily be recognised by the characteristic blue coloration that it gives with iodine. The leaves of a plant thus treated give the reaction after about an hour and a half, whereas the leaves of a normal plant do not turn blue on treatment with iodine. Tlie Origin of Fusel Oil. l""usel oil, long regarded as an objectionable waste pro- duct in the manufacture of spirit, has latterly become an unportant article of commerce, owing to its use as the basis of a solvent for guncotton, in the manufacture of smokeless powders, and for artificial fruit essences, and experiments nave been made to find a means of obtaining it in larger quantity. The most important discovery in this direction is that made by Dr. Ehrlich, of Berlin, who finds that, con- trary to the generally accepted view, fusel oil is formed, not by the action of certain bacteria upon sugar, but by the yeast itself acting upon nitrogenous compounds, such as the amido acids invariably present in decoctions of malt. It transforms these compounds into amyl alcohol (fusel oil), and ammonia, the latter being utilised in building up the protein of its own cells. Dr. Ehrlich also finds that it is possible so to arrange the relative proportions of yeast and sugar that any given amount of the amido acid (leucine) may be added to the fermenting liquid and converted into fusel oil, which may subsequently be separated from the main product (ordinary alcohol) of the fermentation. An abundant source of leucine is found in numerous bye-pro- ducts rich in nitrogen, such as horn shavings and the waste liquors from the manufacture of glue, and this discovery of Dr. Ehrlich indicates the possibility of establishing an important branch of industry in connection with the manu- facture of spirit. EaLrth-£aters and their " Food." Eaters of earth have been known for centuries, and to this day are found in Guinea, Senegal, and New Caledonia, and in various parts of .South .America. The French naturalist, .M. Courty, who recently explored the high table- lands of Bolivia, states that the Indians there are very fond of a paste of clay, which they mix with coca leaves ; but as a rule the earth-eaters take the clay by itself in the form of little pellets dried in the sun or over a slow fire. It has been asserted by certain explorers that the particular earth eaten has really some nutritive value. Humboldt, for instance, writing in 1800, mentioned that the Indians (■n tlie banks of the Orinoco consumed as much as cue and a half pound per day of earth, "qui parait etre nourissante." Two specimens of these earths exhibited in the last Paris Exhibition have recently been examined by M. Balland. One of them, from Gabon, was a light-grey powder, con- sisting of about 95 per cent, of silica, about 4 per cent, of iron oxide and alumina, 0.5 per cent, of water, and traces of magnesia, etc. The other specimen, from New Cale- donia, was of a yellow colour, and contained about gS per cent, of silica, 0.4 per cent, of magnesia, and o.S per cent, of water, with traces of sulphate but was free from iron, alumina, or lime. .\ New Caledonian product, analysed in 1801 by Vaquelin, contained 18 per cent, of iron oxide and J per cent, of copper, the remainder being chiefly silica and magnesia. It is thus evident that these earths have no value as food, and may even be injurious when con- taining copper, although it has been pointed out that they inay have a negative value as .1 supplement to a diet devoid ot woody fibre, c. a bittern, and shortiv after found another dead, " which had April, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 409 evidently hc.sn shot." We join with him in his expressions of regret, and agree further that " It is possible that these two were a pair and might have remained to breed." King Eider in Orkney. Mr. 11. W. Robin-on nrunls | /•';,/,/, MaiL-h 17) the fact that an adult female of the king cider ISiDiuitci ia spectabilix) was shot off the west of Graemsay, Orkney, on February 21. PHYSICAL^ I?V Al-FKEI) W. PuKTEK, 13. Sc. Resolving Power with Wide Slits. In tiie ordinary use of a diffraction grating or prism, it is found to be necessary to use a very narrow slit if two very close spectral lines are to be seen separate from one another ; because each line as seen is simply an image of the slit cmplo\ed. The grating is used with the light falling nearly normal to it ; while a prism is usually set in the position of minimum deviation (i.e., the position for which the incident and emergent rays make equal angles with the normals to incident and emergent face respectively). Mr. Morris-Airey, in a paper in the Pliilosophical Maqazine for March, shows that quite wide slits, or even no slit at all, can be employed without any sacrifice of re- .'■olving power, if the gratmg or prism be placed so that the light strikes it at nearly grazing incidence. Schuster had previously shown that the purity of a spectrum (which is a measure of the smallness of overlapping of images arising from different wave-lengths), is given by _l (5?v) _ 2X+ Am Purity ~ IT ~ XK where (SX) is the smallest difference in wave-length vi'hich will give distinctly separable images. A is the angle sub- tended at the slit by the iens of the collimator ; w is width of the slit ; and R is the resolving power corresponding to an infinitely narrow slit. Now, Morris-.Virey points out that A should not refer really to the angle subtended by the collimator lens, because only part of the complete beam of light passing through this lens may fall upon the grating. The etfcctivc portion of the lens is that which corresponds to the width of beam received by the grating or prism, and this is very small when Ihe grating is placed in a very oblique position. But as A becomes small, w may be proportionately increased without any loss ol purity ; and, in fact, slits half a centimetre wide may still allow separation of the two yellow lines of sodium with a 1300 line grating. Owing to the magnifi- cent casts of Rowland's grating, made by Mr. Thorp, of Manchester, which are on the market, good gratings are much more conmion possessions than once they were. All who own any such grating can obtain much more power out of them than has commonly been thought. For it is clear that if the slit be not widened when the grating is placed oDuquely, (jrcatcr purity will be obtained. A limit to what can be gained in this way comes in owing to the great loss of light for great angles of incidence. But it would .seem that it is only transmission spectra which will be affected in this way. For reflection spectra, the increased reflecting power is an additional advantage which will enable a narrower slit to be employed. .Anyone who wishes to show spectra on a screen to an audience will find it an immense advantage to make use of the above f.icts. The present writer has jusj; set up a Rowland reflection grating with a slit 2 cms. wide, and with the grating very oblique. The lines of the " Swan spectrum " stand out as quite narrow bands. The spectra obtained are so brilliant that 10 or 12 can easily be obt.iined. The increasing elTect of overlapping as the oider of spectrum increa.ses is very in- structive. .\fcer the first few, the remainiler appear as a succession of reds and greens, very similar in general elTect to the tints of Newton's rings of high order. Of course, in the case of metal gratings not much advantage is to be expected because at normal incidence the reflecting power is at least 90 per cent., but in the case of glass ones very consider.'ible gain may be obtained in exhibiting the reflection spectra. Secondary Spectra. VA'hile discussing a dilTraction grating it may be inter- esting to point out that, besides the spectra usually seen, theory shows that there are a large number of very much feebler ones between each pair of principal spectra. These are the secondary spectra. They must be distinguished from " ghosts," which arise simply from irregularity in the ruling of the grating. Their number between two princi- pal maxima is very great — practically the same as the total number of lines in the grating; thus there will be as many as 80,000 on a 14,000 line grating six inches wide. In practice, they are invisible, and it is usuallv asserted that this is to be expected when the number of lines is large. It is at any rate certain that when the number is small they are very visible. They may be obtained as follows : Cut four parallel slits in a piece of thin brass or aluminium sheet, each slit a millimetre wide and with an interval of i mm. between each. Now by means of a long focus lens focus a narrow and very bright source of light (suitably obtained by putting a very narrow slit in front of the condenser of a lantern, with the lens removed) upon the focal plane of an observing eye-piece, and interpose the four opening grating just in front of the lens so that the light can only pass through the four openings. Take care that the sides of the openings are parallel to the slit. On looking through the eye-piece, a diffraction pattern will be seen consisting, if a piece of red glass be interposed, of a central principal, maximum (the direct image), followed by two feeble second- arv maxima; then a second principal maximum (the " first order spectrum,") ; then four feeble secondary ; then another principal one (the " third order spectrum " — the second order is absent in this case). Everything is repeated in the same way on the other side of the central image. Now it is easily calculated that the relative intensity of any principal maximum and the secondar)- maximum next to it is not very much greater when there are So, 000 lines than what it is when there are only a few. The reason that thev are not visible in practice is that even the principal ones are always comparatively feeble, so that their feeble satellites are bejond detection. If, however, the " direct image " formed by any grating be examined, the satellites are quite conspicuous. With a 20,000 line Rowland grat- ing about six can easily be .seen on each side of the direct image — those of the six being more and more evanescent as they aie more removed from the centre. This simple observation is sufficient to show that there is considerable .agreement between theory and practice even in minor de- tails, although an examination restricted to the lateral spectra .seemed to indicate that there was some disagree- ment. This is by no means the only ca.se in which a pecu- liarity in the effect seen is due simply to imperfection in our sensations of vision. The Joule-Thomson Effect. When a gas is forced through a porous plug, it is usually at a dilfcrent temperature at the two sides of the plug. Considerable interest has centred round this fact, because it can be shown that if a gas were a perfect gas (i.e., one satisfying accurately both Boyle's Law and Charles' Law) it should undergo no change in temperature in such an ex- periment. In reality, it is found that most gases cool at ordinary temperatures in passing through ; hydrogen, how- ever, is an exception, it gets slightly warmer. Olszewski, some years ago, showed that when hydrogen is at a temperature of about 80 degrees C. below zero, it does not change temperature when forced through a plug. This temperature is known as the " inversion temperature," because, for temperatures below it, cooling takes place in- stead of heating. It now appears, however, that most probably this point is not a unique one, and that it all depends upon the pressure of the gas as to what the inversion temperature will be. There is no direct determination except the one quoted above. But calculations based on equations of state, which fairly satisfactorily represent the observed connections between the pressure, volume, and temperature of a given 4IO KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. mass of a jjas when these change, are all unanimous in indicating that for each pressure of a gas there are two inversion temperatures (if any), but that above a certain pres>ure there will be none. The last statement is equiva- lent to asserting that if hydrogen be sufficiently compressed, it will undergo warming in passing through a porous plug, whatever its tempenifure may be. Further experiments are badly wanted on this subject ; and if it should turn out that the above prognostications are not realised, it will merely show that the true equation connecting pressure, volume, and temperature, is not the one upon which the conclusions are based; and we have here, indeed, a most sensitive means of obtaining information about this equa- tion. ZOOLOGICAL. By R. Lydekkek. A New British Fish. .'\mong British freshwater fishes few are of greater interest than the group repiesented by the Lochmaben vendace (Corcijonus I'andesius), the Irish pollan (C. poUan), and several other more or less closely allied forms, each confined to a single lake or group of lakes. All these fishes are members of the salmon tribe, and are near akin to a marine species ; the latter fact indicating that they were at one time in all probability migratory, but have now become confined to the lakes they respectively inhabit. This isolation is doubtless the main factor which has led to the distinctness of the various species. A further illustration of this tendency to differentiation is afforded by the recent dis- covery (detailed in the February issue of the Annals and Magazine of Natural History) that the vendace of Derwent- water is distinct from, although nearly allied to, the Loch- maben species. In allusion to its slender build, it has been named Coregoaus (jiaciliur. The White Winter Coat of Mammals. Much ink has been spent in diseu>^ing tlu- question as to whether animals like the stoat, which in high northern latitudes turn white in winter, do so by changing their coats, or by the bleaching of the hairs of the dark summer dress. It has been demonstrated that the senile whitening of human hair is due to the presence of phagocytes, which devour the pigment-bodies ; and from microscopic observa- tions recently made by the well-known French naturalist, Dr. F,. Troue-~sart, it appears that much the same kind of action takes place in the hairs of mammals that turn white in winter. Cold, by some means or other, causes the pig- ment bodies to shift from the normal positions, and to trans- fer themselves to other layers of the hair, where they are attacked and devoured by phagocytes. The winter whiten- ing of mammals is, therefore, precisely similar to the senile bleaching of human hair, no shift of the coat taking place. Under the influence of exposure to intense cold a small mammal has been observed to turn white in a single night, just as the human hair has been known to blanch suddenly under the influence of intense emotion, and in both cases extreme activity of the phagocytes is apparently the inducing cause. Dr. Trouessart's paper is published in the Comptes- rhulus of the French Biological .Society for February. A Dw&rf Elephant. As the heart of Congo-land is the home of dwarf repre- sentatives of the human race, so, according to a German naturalist, it is the abode of a diminutive race of the African elephant, which probably does not exceed five feet in height. The interest of this dwarf elephant centres in its relation to the extinct pigmy species of Malta and Cyprus, whose teeth indicate that they were nearly allied to the African animal. The Horns of the Wild Sheep. It is a well-known fact that the horns of several species of wild sheep arc always more or less damaged at the tips. This has been explained by some as due to the animals fighting, or to their raking up the snow and ground in search of food ; the latter theory not accounting for the fact that it is only the horns of old rams which are thus damaged. In a recent issue of Shields' Maqazinc Captain C. E. Radclyffe offers the following explanation : — " My own opinion is that the tips are worn down in- tentionally, and that this is done by rubbing the ])oints of the horns against rocks. On inspection we find that the tips are worn away, as if rubbed with a coarse file, and are not broken off. If the latter were the case the remain- ing ends of the horns would be more split and fractured than they are." ... It seems that when the horns attain a certain size and shape their points interfere with vision, and in some cases also with feeding; for occasion- ally they grow into such a shape that when the rams are grazing their points, unless reduced in length, would come into contact with the ground. Somewhat remarkable powers of reasoning ;ire thus attributed by the author to wild sheep. The editor is indebted to the author, Mr. C. O. Esterby, for a copy of a paper on the nervous system of the copepod crustaceans, recently issued by the University of California at Berkeley. Papers R.ead. At the meeting of the Zoological .Society on February 6, Dr. J. W. Jenkinsoii read a paper on the Ungulate placenta, Mr. E. S. Russell described a new hydroid polyp, and Miss Ricardo a new horse-fly; while Mr. H. Schwann com- municated notes on a collection of African mammals, and Mr. Lydekker described others collected by Major Powell- Cotton. The most important paper was, however, one by Mr. 11. G. F. Spurred on the modes of articulation of the vertebrate lower jaw. At the meeting of the same Society on February ^o, Messrs. Doncaster and Raynor described experiments in breeding Lepidoptera, Mr. W. P. Pycraft read a paper on certain passerine birds, Messrs. Thomas and Schwann gave notes on African mam,mals, and Dr. B. Dean discussed the habits of the Australian lung-fish. Protection of Birds. It is pleasing to note in the annual report of the Society for the Protection of Birds, that some humane restric- tive laws are having good results. For example. Lord Curzon's order in India prohibiting the export of plumage, an order which had the support of native religious sentiment in India, has considerably reduced the output, though Indian bird skins and feathers still offered at the London plumage sales show tliat the order is evaded. Tlie stationing of watchers at Dun- geness and on Lundy Island for the protection of sea birds has done good also; and peregrines and buzzards are now nesting on Lundy. The gannets of the Bass Rock are now secure from the guns of idiot trippers; and it is hoped that the St. Kilda wren will be rescued from threatened extinction by tlie Inverness order of last summer. On the other hand, the decrease of swal- lows is still unaccounted for, and there is little hope of saving goldfinches from the imprisonment in the cages of London slums and birdshops to which the Sunday birdcatcher dooms him, unless Sunday were made a close day. That the goldfinch and the king- fisher will recover tlieir number if protected has been shown. Messrs. Newton, scientific instrument makers, have taken into partnership !\Ir. Russell L. Wright (son of the late Mr. Lewis Wright, the author of " Light " •' Optical Pro- jection," S:c.), who has been for some years tfieir works manager and head of their electrical department. April, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 411 New Dinosaurs. Therk seems to be considerable rivalry between New York and Pittsburg, Pa., on the subject of the gigantic reptiles of the Mesozoic age. Hardly had the former town recovered from its ecstasy at the possession of what it fondly believed to be the " biggest reptile on record," in the person of the fine Brontosaurus, pre- sented by Pierpont Morgan, than it learnt to its chagrin that Pittsburg was still leading by a head and about fifteen vertebrae — to be exact, by 17 feet 9 inches, thanks to Andrew Carnegie's Diplodocus, the plaster cast of whose skeleton we have all seen and admired at the South Kensington Museum. Why, we may ask parenthetically, do the Mesozoic reptiles exercise such fascination over American millionaires? Is this an in- stance of elective affinities ? Honours, however, are now easy between the rival towns, for the latest ad- dition to the American Museum of Natural History in New York is the fossil remains of a Tyrannosaurus, the largest carnivorous land animal yet discovered, and the most ferocious monster of the Reptile Age. He was nearly thirty feet shorter than the herbivorous Brontosaurus, but was in every way more formidable, and was distinguished from the other dinosaurs by his agility, his superior brain, and his massive structure. He had immense feet — four feet long by three feet wide — and his total length was thirty-nine feet, while some of his teeth measured as much as six inches. The first bones of Tyrannosaurus Rex, to give him his full title, were brought to light as long ago as the summer of 1902, at Hell Creek, in the bad lands of Montana, which have proved a veritable graveyard of prehistoric animals. During the summer of 1905, a second expedition was dispatched to the same place and a number of additional boneji were excavated from a sandstone as hard as granite. The discovery com- prised so many representative portions of the skeleton of the great flesh-eating dinosaur that the general ap- pearance of the animal can be described with some ap- proach to accuracy. While we may lament the disap- pearance of the placid Brontosaurus or the fragile Diplodocus, we have every reason for congratulating ourselves that Tyrannosaurus Rex is not our contem- porary. He was practically a biped, with an agile, bird-like manner of progression, the immense feet pos- sessing three enormous toes projecting forward, and one extending backward — all furnished with huge tear- ing claws. The head is much larger than that of the Brontosaur, and the great teeth are serrated and sharp- edged. Tyrannosaurus seems to have come in about the time that Brontosaurus went out — perhaps he materially hastened the departure' of the latter. When these monsters ro;imcd the eartli, Montana pos.scssed a sub-tropical climate, not unlike that of the West Indies to-day, the region including great seas of salt or brackish water, the sedimentary remains of which form the " bad lands " of our day. A curious point with regard to the recently discovered plesiosaurian remains in Western Kansas, was the reason for the large pebbles found in (he neighbourhood of the extinct reptiles. These huge pebbles were found inside the remains of the fossilised plcsiosaurs. and it was alternatively suggested that the extinct monster swallowed them as birds swallow small stones to aid the gizzard in the processes of digestion, or that the animal may have had some idea of increasing its specific gravity by adding slones to its weight in order to sink to tin- Icwl of llic nnid liollom where its food was found. It will be observed that doubt and even ridicule have been thrown upon the supposed bird-like digestive habits of these creatures. But according to Professor S. W. Williston, the cumulative testimony of writers both on this and the other side of the Atlantic is quite conclusive. It has been assumed that the plesio- saurs could not have utilised the pebbles as a means of digestion in a muscular stomach. But the modern crocodiles have a real, bird-like, and muscular gizzard; and it is believed that they have a similar habit. ."Xt any rate the habit has been imputed to them, and it is not stretching theory too far to believe that the plcsio- saurs had similar muscular gizzard-like stomachs and originated the pebble-swallowing habit. The special plesiosaur with which the habit is associated is the Eldsmosaunis, which of all animals either past or present had the longest neck recorded. It had no fewer than fifty-eight vertebrae in this portion of its frame, and its total length of neck may be modestly estimated at twenty-three feet. The length of its trunk was nine feet, of its tail eight feet — a great contrast to the 'Diplodocus. The extreme length of the largest-known specimen was probably sixty feet. .\s to the habits of these long-necked plesiosaurs in life, it seems most probable that they were general scavengers, usually living in shallow waters. Arv Ancient Ma-zer: An Old WaLSsa.il Bowl. By Barr-Brown. A M.\ZER of great antiquity is now used as an alms dish in St. John's Church, Glastonbury. It is one of the most beautiful and ornate examples in existence. It has been described as a " brass or latvn-howl." It is An Ancient Latyn Dish, circular in form and in diameter is sixteen and a half inches. The flat rim is two inches broad and its " de- pressed inside seven-eighths of an inch in depth." Oit the f.ice of the rim are two borders a little indented one within the other. In the centre or bottom of the dish 412 KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. is a circular compartment, including an historical legend in bas relief of St. George and the Dragon. There is also King Ptolemy and his Queen, with Sabra, their beautiful daughter. On a thick rim is the ancient in- scription : — " Ich Bart Geluk Aizeit; Bart Geluk Alzeit." " I brought good luck always." The language is that of the Low Countries, which marks it as being of Flemish manufacture; the form of the lettering and the costume of the knight and his palfrey points to an antiquity as remote as the be- ginning of the 14th century. In the old almshouses founded by Edward \T. at Saffron Walden is pre- served an ancient and very valuable wassail-bowl of brown wood with a silver rim, and a medallion in the centre witli the \'irgin and child engraved on silver. Its date is about 1400. A New Oxide of Carbon. By the action of the silent electric discharge on carbon monoxide, Brodie, in 1873, obtained a reddish-brown product which appeared to be an oxide of carbon; to this product the formula C4 O,, or C., Oj was as- signed, analysis giving somewhat variable numbers. Berthclot, in 1876, made similar observations and found also that the brown amorphous product which he obtained, gave, on heating, in addition to carbon mon- oxide and dioxide, a dark coloured substance having the composition CsO:,. With the exception of these somewhat indefinite pro- ducts, which have since received but little attention, chemists have up to the present time recognised only the two well-known oxides of carbon — the monoxide and dioxide. It is, therefore, a matter of considerable interest to learn from Diels and Wolf (Ber. Deut. Cham. Ges. February, 1906, 689), that they have isolated, in a state of purity, a new and definite oxide of carbon having the formula C3O0. It is prepared by the action of phosphorus pentoxide in considerable excess on malonic ester, the change being represented bv the relation :— CH, (COOC, H,) , = 2CH, + 2H,0 + C, O, This new oxide. — carbon sub-oxide, the authors term it — is a colourless mobile liquid, which boils at 7° ; it has an intensely pungent odour, somewhat resembling that of acrolein or of mustard oils, and burns with a sooty blue-edged flame. The composition was deter- mined by combustion, and by explosion with oxygen and the molecular weight by vapour density determina- tion. When mixed with water, it dissolves immediately, forming malonic acid, and ammonia in ethereal solution converts it into malonamide. From these and other properties and from its mode of formation, it may be legarded as an anhvdride of malonic acid, and the authors consider that its constitution is represented by the formula O : C : C : C : O. By spontaneous decomposition, a dark-red amor- phous substance is obtained, which dissolves in water, giving an intensely red solution. H. J. H. Fentox. Erratum. — In the article by Mr. C. A. Mitchell last month on Poisonous Plants used for catching fish, the expression " natural order Derris " should be read as " genus," the latter expression having been used by a slip of the pen. Thickness of the Earth's Crust. By Frank Harris. The persistent survival of gross popular fallacies long after their falsity has been clearly demonstrated, is one of the most gloomy features in man's intellectual out- look. .Some popular errors are, of course, much more reasonably excusable than others; to imagine the earth is fixed in space and devoid of motion is but to accord unthinking belief to the immediate evidence of our senses; and foolish only in that it fails to take into ac- count the evidence presented by all except the most violently striking of celestial phenomena. Far other- wise is it with the popular belief that the earth con- sists of a globe of molten matter enclo.sed in a solid shell no thicker in proportion to its size than is the shell of a hen's egg to its contents; and that assumption of which this belief is the outcome, that the increase in temperature noticeable on penetrating the earth to trivial depths continues without limit towards the centre; for, not only can the first supposition be e;i.sily proved to be absolutely impossible, as can the fixity of the earth in space, but also is there no excuse whatever for the second assumption upon which the first is based; it is an utterly illogical conclusion from our premises. If the earth contained anv masses of dense fluid matter very great compared with the thickness of the enclosing shell, that shell, even if constantly repaired, would be utterly shattered twice in every twenty-four hours by the moon's tide-compelling action on the f^uid mass. If the earth had at any time consisted of a globe of matter all at one temperature, say 7,000° F., and the surface had been suddenly cooled down to its present temperature and so maintained, in one thousand million years the variation in temperature would be quite in- sensible at depths exceeding five or six hundred miles; and the variation near the surface— taking a reasonable co-efficient of conductivity — would be in 100,000,000 years very nearly what is now actually observed. We need not, either, suppose the surface to be suddenly cooled as in the abstract problem. Rock is so poor a conductor of heat that as soon as the surface was solid, a few thousand years — at most say one million — would amply suffice to allow the actual surface to cool down to a temperature so near that now existing as to satisfy the supposed conditions. There is, therefore, no reason whatever for supposing that the increase in temperature does not rapidly tend to. a limit within a short distance of the earth's surface. It is easy to form an approximate idea of what this limiting temperature will be. Supposing, for simplicity, that the earth consisted uniformly of granite; the limiting temperature would be just below that at which granite solidifies under the pressure to which it is there exposed. It makes no difference in essential principle whether we suppose the earth originally to have consisted of a globe of molten granite— as might result upon condensa- tion from a nebula or upon adequate collision tetween two approximately equal masses; or whether we suppose it originally consisted of a solid nucleus surrounded by April, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 413 an ocean of molten rock — as mig;ht have re-sulted from collision between one large and, possibly, sundry smaller masses; in either case it is easy to see what its future history would be. Radiation taking place from the surface only would tend to rapidly lower its temperature there. Convection currents set up in the fluid hereby would constantly maintain an approximately equal temperature through- out the fluid ma,ss; for in a fluid which is of low con- ductivity the effect of conduction is utterly insignificant compared with that of convection. Thus it follows that the temperature would be lowered about uniformly throughout the fluid, so long as fluid existed, and when solidification began the whole would be at about the same temperature, and this temperature would be ap- proximately maintained until the whole was (with the exception of pockets of more fusible matter) completely solidified, for in this case, of course, solidification would take place from the centre outwards. Independently, however, of any assumptions we have here made and of any particular hypothesis, the fact to which we would draw attention is indisputable — there is no reason whatever for assuming that because the temperature increases with the depth it does not rapidly tend to a finite limit. This fact was clearly demon- strated by J'homson and Tait in their Natural Philosophy published a quarter of a century ago. REVIEWS OF BOOKS. Mr. Edwin- Litchfield sends a short article on this sulijecl. After some introductory remarks which have already been imbodied in our previous articles, he con- tinues : " The deeper a mine is, the higher the tem- perature. Let one be sunk half a mile deep, and then, by gigantic labour, make the mine into a valley of ten miles radius — the heat would be gone. Standing on the Welsh or Irish coast, the ground is not hot; dive down into the Atlantic; the " Challenger " did not find the waters beneath to be hot (rather cool), and vet they were five miles nearer the centre of the earth. The cause of heat in mines is from pressure of the 40 odd miles of air above, we sink out of our element, and, I suppose, let the air down out of its; and possibb- the gases in the earth exude, and, prrssod down bv the air above, produce heat. This is fact. Cold air from the mountains in Switzer- land, passing above the valleys, and the sun's rays penetrating the cold particles, cause the undue heat in the valleys. In Melbourne, the cold wind from the .South Antarctic blowing above the warm air from the North and not letting it rise, causes the burning-hot wind which lasts till the cold becomes the master. Often in this island wc find cold weather follows un- usiuil warm days, from the same cause. Were a mine to be sunk through carboniferous rock, and another of even depth, through chalk, the former would be much hf)tter than the latter. It is also out of all conception that the crust of the earth in cooling could bottle up and enclose 7,000 miles diameter of inten.se heat. Should that amount of molten heat, or intensely hot gases be in the interior let us hope it never gets a vent — it woulrl overwhelm the earth and .sea. We must raise some other idea to account for volcanoes and hot springs. I am not aware that the Laurcntian, the first formed rock of our globe, so far as wc yet know, shows sign of having been burnt, and deep borings have been sunk into Siluri.m rocks and yet the water comes up cold. We might try and find some other reason why di-cp mines are waimcr than the top of the .Alps. Elements of Geology, by \V. H. Norton Ginn and Co., the .\th F. Sliilli'igton Scales. ••Jersey," St. Bartiabiis Road, Cambridge.] 4i8 KNOWLEDGE & SCIENTIFIC NEWS. [April, 1906. The Face of the Sky for April. By \V. Shackleton, I'.R.A.S. The SfN. — On the ist the Sun rises at 5.39 and sets at 6.30; on the 30th he rises at 4.37 and sets at 7.18. The equation of time is negligible on i6th, hence this is a convenient date for the adjustment of sundials. Sunspots and faculrc are usually conspicuous on the solar disc, whilst recent spectroscopic observations of the limb have shown many prominences. The position of the Sun's axis, equator, and helio- graphic longitude of the centre of the disc is shown in the following table : — Date. Axis inclined from N. point. Centre of disc S.of Suns Equator. Heliographic Longitude of Centre of Disc. April I ,. 6 .. ,, II .,16 .. ,, 21 ,.26 .. 26° 22' W 26° 30' W 26° 27' W 26° 13' w 25'' 50' W 25" 14' w 6" 28' 6" g' 5° 49' 5° 25' 4° 59' 4° 31' 169"% 56' 103° 56' 37° 57' 331° 57' 265° 55' 199° 51' The Moon : — Date. Phases. H. M. April 2 .. ., 9 •• .. 15 •• .> 23 .. J) First Quarter 0 Full Moon d Last Quarter • New Moon 4 2 a.m. 6 12 a.m. 8 37 a.m. 4 7Pni. ,, lO .. „ 25 .. Perigee Apogee 9 24 a.m. 0 54 Pm. Occult ATioNS. — The following are the occultations of the brighter stars visible at Greenwich before mid- night • — Star's •o Disappearance. Reappearance. Date. Name. 1 ^ Mean Tims. ■ Angle from ■ Angle from 1 s Time N. Ver- N. Ver- point. tex. point. tex. pm. p.m. April 4 IT- Cancri . . . : 5-6 b-.37 119= 14.3" 7.52 271= 279° , 5 REGfLVS • i'3 .1 4« br 102° 6.42 327°, 356° ., 6 X Leonis . . • 4'7 7 3 149° r8i° 7.57 253° 277° .. II ^9 Librae . . • 5-6 10 5b It,5" iq?" 11.30 233= 261° .■ 27 I ig Tauri . . . 4-6 8 51 s.r 42" 9.48 276°, 238' ., 27 laoTauri .. • 5-3 9 28 95" 5b" 10.24I 263°, 227° .. 30 f Cancri .. • 4'7 II 33 110° 70° 12.28! 274° 236° The Planets. — Mercury (April i, R.A. oh 58"; Dec. N. 9° 42'. April 30, R.A. o'' 51™ ; Dec. N. 2°"32') is in inferior conjunction with the Sun on the 5th and hence unobservable at the beginning of the month ; to- wards the end of the month the planet is a morning star in Pisces. Venus (.\pril i, R.A. 1^ 24"! ; Dec. X. 7" 51'. April 30, R.A. 3^ 43'"; Dec. N. 19° 57') is an evening star in Aries, setting about an hour after the Sun on the 1st and about two hours after on the 30th. The apparent diameter of the planet is io"-6, and 0-97 of the disc appears illuminated. Mars (April i, R.A. 2'' 33" ; Dec. N. 15° 18'. April 30, R..\. 3'' 56m; Dec. N. 20" 56') is an evening star in Taurus, setting about 9.25 p.m. throughout the month. The planet may be observed shortly after sunset looking a little north of west, but he does not appear very bright. as he is at a point in his orbit situated at a great distance from the earth. Jupiter (April i, R.A. 4i> 7m ; Dec. N. 20° 22'; April 30, R.A. 4I' 32™ ; Dec. N. 21° 26') is getting more to the west, and is only available for observations for a few hours each evening ; about the middle of the month the planet sets about 10.45 P-m- The equatorial diameter of the planet on the 14th is 34"'6, whilst the polar diameter is 2"-2 smaller. The following table gives the satellite phenomena observable in this country : — • c s g s 1 , " s P.M.'s 1 S J PM.'s 1 1 1 P-M.'s. « s. i/j B< U3 fl, H. M. Apr Apr Apr 4 L Oc. D. 7 54 12 Sh. I. 7 59 24 III. Tr. I. 8 22 S I. Sh. E. 8 18 Tr. E. 9 17 25 11. Sh. E. 8 21 6 III. Oc. D. 9 16 ig Tr. I. 9 4 27 I. Oc. D. 8 27 7 n. Tr. I. 0 10 20 Ec. R. g 26 28 I. Sh. E. 8 32 9 II. Ec. R. 7 55 23 11. Oc. D. 8 57 " Oc. D." denotes the disappearance of the Satellite behind the disc, and "Oc. R." its re-appearance ; " Tr. I." the ingress of a transit across the disc, and " Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow acrofs the disc, and " Sh. E." i'.s egress. Saturn (April i,R.A. 22h47m; Dec. S. 9'' 26'. April 30, R.A. 22h 58m ; Dec. S. 8 ' 25') is a morning star in Aqua- rius, rising about 4 a.m. near the middle of the month. Uranus (April 15, R.A. i8h 37^; Dec. S. 23° 28') does not rise until after midnight ; he is situated low down in Sagittarius. Neptune (April 15, R..\. 6*^ 34™; Dec. N. 22" 19') is on the meridian before sunset, but is observable in the west until midnight ; near the middle of the month the planet sets about i a.m. Meteor Showers : — Radiant. Date. R.A. Dec. Name. Characteristics. Apr.i7-Mayi ,, 20-21 .. ,, 20-22 .. ..30 h. m. 16 0 17 2J 18 4 19 24 + 47° + 30° + 33° +59° T Herculids Small ; short. TT Herculids ' Swift ; bl. white. L> rid Shower Swift. 0 Draconids Rather slow. Minima of Algol may be observed on the nth at 11.33 P-'f-i and on the 14th at 8.22 p.m. Telescopic Orjects: — Double Stars. — 7 Virginis, XII.^ 37"", S.o^ 54', mags. 3, 3 ; separation ^"-g. Binary system ; both components are yellow, though one is of a deeper hue than the other. An eyepiece of a power of 30 or 40 is required on a 3-in. to effect separation. s- Bootis, XI\'.h 36"°, N. 16" 53', mags. 4, 6; separa- tion 6". Requires a power of about 40. e Bootis, XIV." 41", N. 27'' 30', mags. 3, 6i ; separa- tion 2"-6. Very pretty double, with good colour contrast, the brighter component being yellow, the other blue green. J Bootis, XIV.'' 47™, N. 19° 31', mags. 5, 7; separa- tion, 2"-4. Binary; one component being orange, the other purple. Clusters.— M 3 (Canes Venatici), XIII.'' 38", N. 28° 48'. This object, though really a globular cluster of myriads of small stars, appears more like a nebula in small telescopes. It is situated between Cor Caroli and Arcturus, but rather nearer the latter. 419 KDooiledge & Selentifie Neais A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. i8. [new series.] MAY, 1906. r Entered at -1 LStationers' Hall.J sixPEN'ci: m:t. CO\TENTSSee page VJI. Astronomical Photography. Hints to Amateurs Regarding Appliances and Methods of Working. By Alexander Smith. II. Adapling Telescopes for Photographic Purposes. — Both refracting and reflecting- telescopes may be utilised for photographic purposes, but unless the former type of instrument is specially corrected for this kind of work the chemical and visual foci will not be coincident. The difference may be ascertained by making a number of short exposures, and noting the plane at which best definition is obtained. Photographic achromatism is sometimes secured by altering the distances between the crown and flint lenses, and sometimes b\' using a third lens specially corrected for the purpose. Triple object-glasses suitable for both visual and photographic work are now procurable, but are very expensive. The reflector is, however, the type of instrument which ap- peals to the ordinary amateur, who is desirous of taking up astronomical photography, as perfect achromatism is .secured at a comparatively small cost. To adapt a well-mounted clock-driven instrument of this class for such work, few additional appliances are required. A guiding telescope — either reflector or refractor — will have to be provided, and the aperture should preferably be not less than four or five inches. A plate-holder with suitable carrier will also be required. The latter may be attached to the telescope with a piece of brass tubing of the requisite diameter to slide firmly into the eye-tube. To one of its ends a flange is fitted, by means of which the tube is attached by screws to the carrier, the necessary focussing adjustment being made by the rack of the telescope. With large reflectors, used solely for photography, a flat is usually dispensed with, and the plate placed in- side the main tube at the primary focus of the mirror. The plate thus practically takes the place of the flat, and is supported in a similar fashion by three thin pieces of steel. The plate-carrier is attached to a short length of stout brass tube, inside of which another tube, worked by rack and pinion, slides, and by which the final focussing adjustments are made. The dark- slide is fitted wltii a shutter, which folds back in the line of focus, where it is held in position by a spring catch. In some cases a flap-shutter is also fitted to the carrier, and is raised or lowered by means of two strings, a small weight attached to either string keep- ing it in position. In such equipments the mirror has usually a central aperture, through which the brighter objects on the plate can be directly examined with a small telescope, and, in the case of long exposures, it can also be ascertained by the same means whether anv displacement of the speculum has taken place. Enlarging Lenses. — With instruments, such as are generally to be found in the hands of amateurs, the discs of the sun, moon, and planets at the primary focus of the mirror are too small, particularly in the case of the phsncts, to exhibit much in the shape of detail, compared with the results which are obtained \isually when an eye-piece is employed. At the same time it is astonishing how much detail can be shown by enlargements from such photographs, if the method afterwards dcscrilx^d is adopted. It must, however, be conceded that a negative obtained by enlarging the primary image by a lens in the telescope will exhibit less of " grain " than if the image is directly transferred to a photographic plate and afterwards enlarged to the same dimensions. Different forms of enlarging lenses mav be success- fully employed, the most popular probably being the Rarlow " and low-power positive eve-pieces. X'erv fine results may also be obtained with the negative components of telephoto len.ses of the better ^lass, which give a very flat field, and have the additional ad- vantage that only a short extension of camera is re- 420 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. quired. When it is desired to secure an enlarged photo- graph of the whole of the solar or lunar disc, the diameter of the lens must, of course, be at least equal to that of the primary image. To bring such lenses into use some form of camera is necessary. This can be attached to the eye-tube of the telescope in the same manner as the carrier previously referred to. Fig. 3, which is self-explanatory, shows the complete arrange- ment as used by the writer. The enlarging lens is fixed in a sliding tube, and, through the small door with which the camera is fitted, it can be moved nearer to or further from the plate to increase or diminish the amount of magnification, the focussing being accom- plished by the rack-work of the telescope. For planetary work a screw similar to that pre\iously de- scribed, and which is also shown in the figure, can be brought into use, and se\eral exposures put on the same plate. Shifters. — It will be found of great convenience for regulating the exposure if some form of shutter is attached to the eye-tube of the telescope. The type adopted should have a fairly large opening, work smoothly, and admit of giving " time " and " instan- taneous " exposures. It should be fitted with a short length of brass tube similar to that described for the camera and plate-c;irrier. It mav then be readily placed in position by sliding the tube into the end of the eye- tube which is next the flat, and, consequently, inside the telescope, the release being most conveniently effected bv the usual pneumatic ball. Drivi7ig-Clock\. — Manv amateurs possess driving- clocks, but only a small proportion of these give suffici- ently accurate results to enable their owners to take up photographic work in a svstematic fashion. In some cases failure may arise from faulty construction of the mount. The polar axis may be too short to secure the requisite rigidity, or, what is a more common defect, the driving-worm, or pinion, as the case may be, is geared to too small a sector or circle. If a larg-e sector Fig. 4. be used, very little strain is put upon the driving mechanism, .-ind a greater measure of steadiness is at once secured. Fig. 4 shows a sector of two feet radius with the driving-worm geared in position. It is very important that both the driving-worm and sector be" accurately cut, otherwise slight movements of the image in the field will be apparent, although the motion of the clock may be perfectly regular. In the matter of clocks, perhaps the most frequent source of trouble arises from the method of control, the ordiuarv fiiilional governor being uncertain in Fig. s- action, and, where accurate driving is essential, necessi- tating the introduction of electrical or other complica- tions. For time-keeping purposes no method of control equals the pendulum for steadiness and reliability, but pendulum clocks in the ordinary form are quite useless for driving astronomical instruments, for the simple reason that they are fitted with escapements, which only admit of motion in the form of short though regular impulses, while for astronomical purposes the motion must be continuous. A clock can, however, be con- structed whereby this result is obtained, and the ad- vantages of the pendulum control at the same time secured. When the principle on which its utility de- pends is once understood the constructional details mav be worked out in a variety of ways. This principle may be made clear by referring to '■'§^- S> which is intended to illustrate the action of a train of wheels on a single pendulum. A represents the clock barrel, B the driving weight, and C the pendu- lum. When the barrel rotates, motion is conveyed through the intervening wheel D to the bevel pinion E, and thence to the vertical spindle F, on the upper end rf which there is fitted a short crank, which, in turn, communicatees its motion through the connecting-rod G to the pendulum C, and as the latter swings backwards and forwards it regulates the rate of motion of the whole arrangement. A single pendulum will not give so satisfactory results as 3, and this is the minimum number recommended for a clock of the kind. Fig. 6 is a photograph of a 3-pendulum clock of this description, which the writer found to give excellent results. On the top of the vertical spindle to which the crank is connected a train of .small wheels terminating in a "fly" should be fitted, for the purpose of intro- ducing a certain amount of flexibility in the drive be- tvi-een the clock and pendulums, in order that the oscilla- tory motion of the latter may be started and stopped May, igo6 ] KNOWLEDGE & SCIENTIFIC NEWS. 421 gradually and without shock, which would not be the case if the pendulums were rigidly joined to the rest of the driving mechanism. A larger clock controlled by five pendulums, each 3 feet 3 inches long, was subsequently used, and when everything was properly adjusted the motion was so reliable and certain that when engaged in photographic work it was only necessary to examine the image in the guiding telescope at intervals of a few minutes. Not- withstanding extended trials with both types, it is diffi- cult to express a decided opinion whether five pendu- lums give better results than three. A greater measure of steadiness appears to be secured by adding to their length than by increasing the number. Three must, however, as already pointed out, be regarded as the Fig. 6. minimum, and their length should preferably not be less than three feet. Having briefly described the various appliances which may be brought into u.-^e by those desirous of taking up astronomical photography, a few hints, biused on the writer's experience, will now be gi\en regarding methods of working. Solar Photography. — In selecting plates for photo- graphing the solar image the slowest brand procurable should be adopted; indeed, it may be pointed out as an invariable rule, that, where a sufficiently long exposure can be given with a slow plate, it should always be selected in preference to one of greater rapidity. Rapid plates do not give the same amount of delicate detail, neither do they admit of the same latitude in exposure. It is only in ca.ses where very prolonged expn^sures ai'e ejisential that their u.se becomes a necessity, at least so far as astronomical purposes are concerned. I-'or solar work a good brand of lantern plate will probably be found to give the best all-round results. All piates should be backed with a suitable medium. No hard- and-fast rule can he laid down with regard to the dura- tion of exposure, as this is appreciably affected by the position of the sun at the time the photograph is secured, but as a rough guide it may be slated that on a summer day w ith the sun placed in a clear skv, and the telescof>e stopped down to an angular aperture of f /60, an exposure of i-40th of a second on a lantern plate will be found to be ample. In other words, if a tele- scope of a focal length of 10 feet is stopped down to an effective aperture of two inches, the exposure required will be about i-4oth of a second. If the primary image is enlarged by a lens, a correspondingly increased ex- posure must, of course, be given. Lunar Photography. — In taking photographs of the moon, the beginner will soon discover that, in order to secure the desired amount of detail, the terminator requires a longer exposure than the rest of the illu- minated disc, and that by giving exposures of varying duration the apparent age of the moon may be altered by several hours. At least three methods may be brought into use for getting over this difficulty. (l) A strip of cardboard, one end of which is similar in size and shape to the lunar terminator, may be introduced by the hand into the end of the telescope tube, and moved slightly backwards and forwards in front of the shutter for, say, two seconds, and rapidly withdrawn. It is to be understood that during the first part of the exposure the terminator only is to remain uncovered, and, if the shutter is closed after an interval of another second, the terminator will thus get an exposure of three seconds, and the rest of the disc one-third of that amount. (2) The plate may be given an exposure in the telescope suited to the terminator, and afterwards de- veloped. A positive is then taken from the negative by contact, but during the exposure of the plate to the source of illumination a strip of cardboard, similar to that prexiously referred to, is brought into use, and moved slightly backwards and forwards over the image of the terminator during two-thirds of the total ex- posure, and then withdrawn. Another negative can be taken from the positive thus obtained either by con- tact, or, if a camera is used, an enlarged image may be obtained at the same time. (3) The plate may be exposed in the telescope as before, and the resulting negative afterwards reduced in density where necessary by the local application with a soft brush of a reducing solution, such as that known as " Farmers " (Satu- rated solution of Ferricyanide of Potassium i part. Hyposulphite of Soda solution i to 5, 10 parts). If the method first referred to should not give the result aimed at, the defect may be removed by method No. 2 or 3, or all may be partly utilised in the production of a single negative. If a lens is used in the eye-tube of telescope to en- large a portion of the primary image, the illumination will be more evenly distributed, and the plate under such circumstances may be treated in the usual way. Planetary Photography. — Unless a telescope of long focus is avaihible, no very satisfactory photographs oi any of the planets can be obtained, and even the best results, which ba\e so far been secured compare un- favourably with the \ lews which a comparativelv small instrument presents to the eye of the observer. When dealing with such a small object, it is advisable to use an eye-piece in conjunction with the telescope to enlarge the primary image, and in the case of the brighter planets the aperture should be stopped down to reduce the intensity of the light with the view of being better able to regulate the exposure and development. Care should be exercised that these are not too prolonged, otherwise the small discs will be enlarged by the effect of halation, and all detail effectuallv ob.scured. On the accompanying plate a few examples are given if planetary and lunar photography. With the excep- tion ot l-'ig. 10, where a lo^ inch mirror of 6 feet 422 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. rig. 11 May, 1906J KNOWLEDGE & SCIENTIFIC NEWS. 423 5 inches fcx;us was used, all the photographs were taken with the same telescope, viz., a i2i-inch reflector having a focal length of 10 feet. This instrument, which was formerly used by the writer, is now in the hands of Mr. Maciachlan, of Largs, who made the original exposures from which Figs. 8, 11, and 12 have been produced. It will be understood that all the original negatives were subsequently enlarged with the camera, and details of the method employed will be given in another paper. Fig. 7 shows four photographs of the planet \'enus, taken January 13, 17, 28, and 30, 1902, at the primary focus of the mirror. A slow plate was used, and the duration of exposure was about half a second. The images were afterwards mounted on a strip of glass and enlarged together. Fig. 8 is a photograph of the planet Jupiter, the primary image in this instance being directly enlarged in the telescope wth a low-power Ramsden eve-piece. The exposure given was two seconds, and the plate de- veloped with a solution of normal strength. Fig. g was taken at the primary focus of the mirror, the lunar terminator receiving three times the amount of exposure given to the rest of the disc. (See method No. I referred to under " Lunar Photography.") Fig. 10 was taken during the last phase of the lunar eclipse of April 11, 1903. The exposure in this case also was made at the primary focus. In the production of Figs. 11 and 12 a Ramsden eye- piece was used in the telescope to enlarge a portion of the primary image, the exposure in each instance being 10 seconds. Those who are acquainted with lunar typography will readily recognise the regions depicted on the prints. Fig. 1 1 shows a portion of the termina- tor in the vicinity of the craters Bullialdus and Tvcho, while Fig. 12 is a photograph of the well-known crater Copernicus and the surrounding region. (To he continued.) Simple Rule for Squaring any Number. Rules for simplifying arithmetical calculations have often been published. The following simple method of squaring any number is somewhat interesting. It ought probably to be taught to beginners in connection with extraction of square root of which it is the con- verse, and an instructive exerci.se is afforded by squaring numbers by this method and verifying (he correctness of the answer by long multiplication. Suppose it is required to find the square of 5342.7198, the multiplications being carried to four decimal places; the process stands as follows : — 53427198 X 5342719S 5000 X 5000 = 25030OCO 103 X 3 = 3cg 1064 X 4 = 4256 10682 X 2 = 21364 10684-7 X '7 = 747929 10685-41 X I = 106-8541 10685-4 X 9 = 96-1689 10685 X 8 = 8-5:83 2854.1654-S613 \\'ith a liltle practice, the successive lines of multi- plication could be written down nicntally without w-rit- ing down the successive niultiplicands and multipliers. Xumbfrs mav be easily cubed or raised to any desired j)in\or by a kind of reversed Horner's process, very similar in principle to the above, but it is doubtful how far any further extensions of the method are suited for teaching purpo.ses. G. H. B. Spitzbergerv and its Whale Fishery. By T. Southwell, F.Z.S. It is only of late years that anything like order has been established in the classification of, or any import- ant advance made in, our knowledge of the distribution and life history of the members of the important family of marine mammals known as the Cetacea, or whales and dolphins, and this especially applies to the whale- bone whales of the northern hemisphere. It will hardly be believed that although the great .Arctic Right Whale has been known since the year 1610 and many thousands of them killed, so rare is the skeleton of this animal and so difficult for various reasons to obtain, that it is still a desideratum to our Xational Museum; but owing to the establishment in Northern Europe and .■\nierica of whaling stations for the pursuit and capture of the giant Fin Whales (Balaenopteridee), rendered possible by the discovery and perfecting of a mode of attacking tht-m by explosive harpoons, the invention of Herr Foyn, a Norwegian whaler, abundant material has been rendered available for their study and accurate description. Still it is very remarkable how slow the general public is to appreciate this advance, and how singularly they fail to distinguish between the various distinctive branches into which the family is divided, even confounding, as will be seen below, those armed with teeth with those furnished with the remarkable appendage know'n as baleen, or whalebone, the feature on which the main division of the order is based, namelv, Mvstacoceti, or \\'halebone w'hales, and Odontoceti, or those furnished with teeth. Even in the writings of acknowledged authorities we sometimes meet with strange statements. For instance, in one text book we are informed that a Right Whale mav produce several " tons " of whalebone, a most liberal allowance, and at the present price of ^.2,250 per ton, a very valuable asset; another authority states that the Right Whale, though found in the seas on botli sides of Greenland, passing freely from one side to the other, is never seen so far south as Cape Farewell. The first statement is doubtless due to the intervention of one of th(3se evil spirits specially allocated to the office of the printer, who wickedly substituted the word " ton " in the place of hundredweight; the second is probably an oversight, for its author was one of our most accomplished cetologists. That the Right W'hale is (or was) found on both sides of Greenland is un- doubtedly true, but as it never descends so far south as Cape Farewell it is difficult to understand how it can pass frei'ly from one sea to the other. .\ charming writer and a leader in the world of science evidently never acquainted him.self with the learned researches of Prof. Eschricht, for he adheres to the old belief that the whale formerly hunted by the Basques in the temperate regions of the .Atlantic, through persistent persecution has retreated to the ice-fields of the Polar regions, whereas the speci-.^s inhabiting these two areas are per- fectly distinct. Of late jjersonally-conducted tours have been extended even to the icy regions of Spitzbergcn, and, of course, the travellers to this No-man's Land have fa\ourcd their les.> adventurous bretiiren, by means of the public press, with the results of their peregrinations; and as the tourist is almost invariably furnished with a " Kodak," the illustrations to their articles are, as a rule, excellent. 424 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. and give a fictitious value to the letterpress which is generally poor stuff enough. Two of these articles deal- ing with the .Shetland Fin Whale fishery, one of which appeared in Temple Bar for .September, 1905, and the But a more pretentious article, giving an account of a trip to .Spitzbergen and of the whale fishery carried on thorc by the N'orwegian vessels, has recentlv ap- peared in an old-established journal, which I have for The Polar Right Whale (Balama mtjMcelm). 'rom nclitnl mfasuremenU hij the lute Cn])t. Diirul Grtnj, of the .S'.S. "Ec/i/)J*f,** vhnler. Other in the Illiistralcd Sporting and Dramatic Xai's on the c)th of the same month, are all that can be desired, but in ;i third article, in another illustrated periodical, dealing with a visit to Spitzbergen, the author tells us many years read and admired for its usuallv .short, crisp, and well-informed articles; but in this instance the editor has evidently been caught napping, .so far as it relates to whaling, notwithstanding the fact that the The Sperm Whale iPhijacttr mncrocrjhalus). From SouthxcelVs " Siah and n ;,«(« of the trifuU Seat.' that " the .Sperm Whale, from which the best whale- bone Is obtained ... is. becoming rare! " It would be dilllcult, did one try, to embody an equal amoimt of inaccuracv in so few words. editorial chair is usually considered quite other than conducive to somnolence. The author ol the paper, after giving a brief history of the discovery of the group of islands and of the flockinij thither of the various May, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 425 nationalities to participate in the capture of what he calls " the ' Right ' or Sperm Whale," states that " the competing whalers had the good sense not to quarrel on the spot, and a fair division of the spoil (?) was ac- cordingly arranged," a statement than which nothing could be farther from actual facts, as I think tlie follow- ing statistics will show. Shortly after the discovery of Spitzbergen by the Dutchman, Barentz, in 1596, our countryman, Henry Hudson, followed the same course, and his glowing account of the vast numbers of whales and walrusses there to be found induced the English Muscovy Com- pany, in 1610, to send out vessels for their capture; thereupon, under the impression that the Spitzbergen group formed part of Greenland, the Danish Govern- ment at once annexed them, but our James I., not to be behind in securing so productive a territory, lost no time in also asserting a claim to the islands and the adjacent seas, and although the assumption on which the King of Denmark based his pretensions proved not to be tenable, I am not aware that either claim has ever been officially renounced. In 1612 the Dutch followed us to Spitzbergen, and for the next thirty years a fierce contention raged be- tween the linglish, Dutch, Danish, and Trench crews for supremacy with varying success and frequent reprisals, the Dutch and Danes often calling in vessels of war to their assistance, whilst the diplomatists at home fought wordy battles with equal vigour. On the whole, the Dutch, who generally worked fairly harmoni- ously with the Danes, seem to have had the best of it, and in 1623 they began to erect permanent settlements on the shore for rendering down the blubber, which eventually expanded to a considerable settlement known as Smeerenburg, of the " rise and fall " of which Sir Martin Conway has given such an interesting account in a privately printed pamphlet (undated); they also had depots in the island of Jan Mayen. For having roughly driven two l?iscayan vessels from their fishing grounds, only to subject them to similar treatment from the English, the Frenchmen took a speedy revenge. Stay- ing behind until the Dutch had returned home, they pillaged the Jan Mayen station, loading up with the spoil, which they sold in France, and destroying what they could not remove. After the sack of St. Jean de Luz by the Spaniards in the winter of 1636, when the French whaling fleet was practically destroyed, very little is heard of the Biscayans, and they finally ceased to send out vessels in 1639. In 1642 the much persecuted whales began to abandon the bays where once they had been so plentiful, and the vessels had to follow them into the ice. This led to their adopting the plan of trying out the blubber at .sea or carrying it homo to extract the oil, thus rendering the shore stations useless, and they were gradually abandoned, till, by 1653, Sir Martin Conway tells us, the once famous summer settlement of Smeerenburg was finallv aban- doned It need hardly be said that the animal w liich formed the quest of these ancient mariners was the Polar Right \Vhalc, which yields the valuable " whalebone " as well as oil, and that the Sperm Whale, a toothed whale inhabiting the southern seas, was quite unknown to them, or, at most, only occurred as an accidental wanderer in the Arctic seas. The Right Whale has of late years been practic.ilh- exterminated in the East Greenland seas, and those now fished for from Shetland, Iceland, and Spitzbergen are various species of " Finners," which occur in con- siderable numbers and yield a varying quanlitv of oil .iccording to the species, but far less than the Polar whale; their whalebone is also short and brittle, and of little value. When these whales are killed they rapidly sink, and are difficult to recover; therefore, it has be- come the practice to pump air into the abdominal cavity to cause them to float, but I never heard of " gas " being injected for that purpose as stated by the maga- zine writer referred to, and if he is not mistaken it is quite a new departure. Decomposition sets in very rapidly in a dead whale, and the appearance which the author of the paper very excusably mistook for the extrusion of the tongue is a prolapse of the lining membrane of the throat caused by the pressure of the air in the abdominal cavity; this is seen in the case of stranded whales which have been some time dead, and would doubtless be more pronounced after artificial in- flation. The extent to vi^hich these Fin Whales have been persecuted since Herr Foyn's invention in the waters of both Europe and America has already greatly reduced their numbers, and it needs no great gift of prophecy to predict their early extermination; they are slow of re- production, and long in coming to maturity, and the only hope is that when they become too scarce to render their pursuit profitable a remnant may be left to insure the continuance of the race. I hope it will not be thought that in penning the above remarks I am merely indulging in carping criticism. My object is to call attention to the want of even rudi- mentary knowledge of these interesting animals on the part of the general public, notwithstanding the many excellent recent works on X'atural History to be found in all our free libraries. It might possibly be excused that the uninitiated should fail to distinguish between the Right Whale of the North Atlantic and its relative inhabiting only the Polar Seas; but that the latter should be confounded with the Sperm Whale — so totally differ- ent an animal— whose proper home is in the Southern Oceans, is simply incredible. It is not easy to make the personal acquaintance of these giant animals, but a visit to the whale-room at South Kensington Museum ought to convey much g'eneral information, and I can promise those who pursue the study that they will find it a very fascinating one. Royal Institution. — The following arc the Lecture Arrangements at the Royal Institution, after Easter : — Professor G. Baldwin Brown, Two Lectures on Greek Classical Dress in Life and in Art; Professor William Stirling, Three Lectures on Glands and their Products; Dr. P. Chalmers Mitchell, Two Lectures on The Diges- tive Tract in Birds and Mammals; Rev. J. P. MahafTy, Two Lectures on (i) The I-'xpansion of Old Greek Literature by Recent Discoveries; (ii) The Influence of Ptolemaic Egypt on Gra-co-Roman Civilisation; Pro- fessor William J. Sollas, Three Lectures on Man and the Glacial Period; Professor Charles ^^'aldstein, Three Lectures on linglish Furniture in the Eighteenth Cen- tury; Professor Sir James Dewar, Two Lectures on The Old and the New Chemistry; and Professor W. Macneile Dixon, Two Lectures on (i) The Origins of Poetry; (ii) Inspiration in Poetry. The Friday Evening Meetings will be resumed on April 27, when Professor John W. Gregory will deliver a Discourse on Ore De- posits and their Distribution in Depth. Succeeding Discourses will probably be given bv The Hon. Charles .\. Parsons, Professor J. H. Povnting, Professor Arthur .Schuster, Mr. I^onard Hill, Professor H. Moissan, and Professor Sir James Dewar, and other gentlemen. 426 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. Irritability. Reaction of Protoplasm to Stimuli. Bv Harold A. Haic, M.B. Protoplasm will react to external stimuli and within limits can adapt itself to stimuli of an unusual and powerful nature. But if these latter be too long sus- tained a complete or partial cessation of function will result. Let us take the case of a turgescent root-hair sur- rounded with a dilute aqueous solution of various salts. Some of these salts will be selected to the exclusion of others, the protoplasm lining the cell-wall, or, rather, the laver known as the ectoplasm, showing what is known as a selective capacity for certain salts. Now this process shows us that tlie ectoplasm by reason of its reaction to the stimuli of .some salts and not those of others acts as a kind of .sieve, and keeps up the requisite osmotic equilibrium. A non-living membrane shows no such predilection for some salts over others; in fact, there must exist in our layer of protoplasm the capacitv of reacting specifically to some kinds of chemi- cal stimuli over and above others. Take again the case of naked masses of protoplasm (Plasmodia) when subjected to the influence of some irritant : retraction will in some cases occur, in others attraction, and here again we find the same kind of specific irritability. These phenomena are not to be explained on purely physical or chemical lines, but are of a complex nature in which both physical and chemi- cal changes occur. Later on we shall see that rapid changes in metabolism have probably a large share in the production of the various external manifestations such as alterations in shape of the protoplasm, move- ments, and so on; but some of the intrinsic molecular changes which take place when a stimulus is applied to protoplasm are so hidden that as yet no satisfactory theorv has been advanced to explain all the changes which take place between a stimulus and its effects. In the animal cell we find conditions are somewhat different; in the first place we cannot make any distinc- tion between an outer transparent and an inner granular laver of protoplasm, such as is possible in plant cells, and, moreover, no true cell-waJl exists. Under the influence of certain irritants, as, for instance, the mineral acids, we find that living cells from a given part of the body, such as the skin, will, some of them, become completely disorganised, and adjacent cells show signs of increased rapidity of division, a fact pointing to a reparative process, and due to the stimuli tr.insmitted by neighbouring injured cells. Instances of this reparative process occur at times in plants, as in the case of the production of a cushion of callus round the edges of .-i cut made through the bark of a tree so as to mclud;' the cambium and xylem; and in the overgrowth whic-h occurs in certain cases where a parasite attacks a plant. In those cases where animal cells are exposed to the action of the bacterial toxins, a very complex result often ensues; in some cases, as is well known, the cell will resist the poison, and produce substances known as antitoxins, which tend to arrest or neutralise the action of the bacterial toxin. In other cases toxic bodies are formed outside the bacterial cells from sub- stances either in the animal cell or from the media surrounding them (extracellular toxins), and these, by their irritant action, either kill the cells or stimulate them to form antitoxins. When :i cell becomes incapable of reacting to the irritant, it undergoes a process of degeneration (fatty degeneration), which ends in complete disorganisation and breaking up of the protoplasm into droplets of fatty material. Often certain cells take on a reparative or protective function, and form a laver round colonies of bacteria, enclosing them and finally indirectly affecting their destruction (as in an abscess). We see, then, that in both the plant and animal cell a definite reaction takes place whenever the cell is ex- fvosed to an irritant; in the plant cell there is in most cases cither immediate cessation of function, where the irritant is powerful enough, or the occurrence of a physical or chemico-physical process, which tends to remove the protoplasm away from the source of irrita- tion when harmful, and place it in a kind of defensive equilibrium. In the animal cell, on the other hand, the first indication of reaction is one of increased cell-divi- sion (where vascular tissues are concerned there is also an emigration of certain cells, leucocytes, which act partly as phagocytes and aim at destroying the irritant), followed in some cases bv the formation of a layer of cells, which enclose the irritant and proceed with re- pair. Now, it may be asked, why should protoplasm react in this manner to stimuli? The retraction of Plasmodia awav from an irritating substance, and the increa.sed rate of cell-division in the animal cell when stimulated cannot he due to purely physical or chemical causes acting separately. When we say that " irri- tability " in a plant or animal cell is that property which enables it to react to a stimulus of whatever nature, we merely state the bare fact that by reason of it certain changes occur which somehow alter the previous rela- tions of the protoplasm, but we offer no explanation as to why such changes should occur. .\s a matter of fact, it is probable that intrinsic changes do take place in the ultimate physical constitution of the protoplasm, whereby a rearrangement of molecules takes place with- out altering the general chemical constitution. The change, in fact, must be very similar to what takes place when a nerve transmits a stimulus from its peri- pheral to its central end or vice versa ; in this latter process it is known that electrical changes take place, a fact which points to the occurrence of rapidly alternating anabolic and katabolic changes, these manifesting them- selves in a current which travels in a certain definite direction. Recentiv it has also been shown that anv li\ing pro- toplasm will manifest electrical changes when irritated, pointing to the same anabolic and katabolic changes, and the quiescent protoplasm of seeds which have lain dormant for years will, when an inciting current is passed through them, show what has been called a "blaze-reaction," that is, an electrical respon.se-cur- rent, which indicates that the protoplasm is irritable and has reacted. (See Dr. \\'aller's Experiments with Seeds.) Experiments such as these have enabled us to gain some little insight into the complex processes involved in the reaction of protoplasm to irritation, but still they do not show us how it is that increased anabolic and katabolic processes are set going subsequent to irrita- tion. That metabolism produces electrical changes is well known, and such changes are, of course, the .sequel of any chemical and many physical processes; living May, igo6.J KNOWLEDGE & SCIENTIFIC NEWS. 427 protoplasm must be looked upon as being a substance of extremely unstable constitution, such, indeed, that the slightest stimulus will cause an immediate kata- bolic followed by a rapid anabolic change, both of these being an increase of the usual metabolic changes. This change is capable of being transmitted from cell to cell by means of the protoplasmic connecting strands, and it is thus that we are able e\en in plants to explain the transmission of stimuli from one part to another of the same organism. The anabolic change is to be looked upon as a process tending towards repair, but the protoplasm remains in the same unstable equilibrium as before. Protoplasm that has been killed has passed into a state of stable chemical and physical constitution, and has undergone a complete change with regard to the arrangement of its indi\idual molecules; in fact, it is the very instability of living protoplasm that endows it with its peculiar property of responding at once to stimuli. Protoplasm once dead is open to the ordinary processes of chemical decomposition, but on account of the stable arrangement of its molecules is no longer capable of responding to external stimuli. One of the most important conditions for the retention of irritability is the presence of oxygen, whereby metabolic changes can proceed; and the presence of water both in combina- tion with the protoplasm and otherwise is essential, all living protoplasm having some " water of constitution " which is present in the protoplasm of the driest seeds. Naturally, in living protoplasm, anabolic and katabolic changes are always proceeding to a certain extent, and when above we mentioned the rapid succession of these processes as being one of the essential concomitants in the reaction of protoplasm to stimuli, it was meant that these processes occur then with greater intensity and in regular alternation. A " Current of Rest " is always present in living protoplasm, but when a stimulus is given to it, anabolism and katabolism proceed with a fixed period of alternation, and with greater intensity than before, giving rise to an increased current or " cur- rent of action " — very similar to what happens when a muscle passes from a state of rest into one of contraciion. In fact, a close analogy might he drawn between a muscle and a cell; a muscle responds to a stimulus by contracting, and during this contraction certain electri- cal changes take place, metabolism is increased, and heat is produced; the protoplasm of a cell responds to stimuli by, perhaps, some aJteration in shape, or in some cases by more rapid movement round a cell cavitv, and during this metabolism is increased ;ind electrical changes take place. But in both cases it is probably the more rapid succession of the metabolic changes, consequent on the stimulus, that is the cau.sc of the outward manifestation; as to the alteration in the physi- cal arrangement of the molecules, this is as yet un- determined, but, with the increa.se in scientific know- ledge, will no doubt be <\plaincd at .1 later date. The Chemistry of Proteids. Rare Elements.— .\ revised table has been compiled bv Mr. E. L. N. .\rmbrecht, and is published by Messrs. .^rmbrecht', Nelso.i & Co, of the Rare Elements. The table, which is of considerable interest as well as of great utility, gives the symbol, specihc gravity, atom's weight, principal source, and chief prope.-ties of each of some seventy of the rare elements. The nam^ of the discoverer and in some cases the name of the chemist who first isolated the metal or element is also added ; and, by no means least in importance or interest, the market price of the element is furnislied. I'rom this it appears that, subject to the natural fluctuations. Yttrium, Vanadium. Thorium, Tantalium, Rutlieniura, Rubidium. Rhodium, Niobium, Lanthanum, Iridium, Indium, Erbium, Beryllium and Barium are the chief of the rare eleme Us which are worth upwards of a shilling a grain. By Ida Smedley, D.Sc. Of the three great classes of substances which form the chief products of animal metabolism — fats, carbo- hydrates and proteids — the last-named have for long withstood all efforts to determine the nature of their constitution. Although this problem has occupied the attention of more workers than almost any other group of substances, it is only within the last five years, chiefly owing to the brilliant work of Emil Fischer and his pupils, that we are in a position to form some definite conception of the nature of their atomic structure. The steps made in this direction have so far only led us to the synthesis of peptides, substances of much smaller molecular size than the native proteids, bearing, how- ever, considerable resemblance to them, and occurring among their cleavage products. Such syntheses may probably be regarded as analogous to those of the simple hexose sugars, the structure of starch and of the more complex carbohydrate molecules remaining unsolved. The earlier investigators were very largely concerned with the isolation and classification of individual pro- teids; the latter based mainly on differences in two physical properties, temperature of coagulation and solubility in the presence of inorganic salts. Unfor- tunately in dealing with these colloidal substances, the identification of chemical individuals presents great difficulties, the properties relied on in classification be- ing those which would be readily affected by the pre- sence of impurities. It has recently been shown that members of two of the most sharply differentiated of these classes, the albumins and globulins, under certain conditions suffer mutual conxersion. A more satisfac- tory scheme of classification will probably be based on differences in their chemical structure, but for this, a knowledge of their decomposition products and the pro- portions in which they are present, more complete than we at present possess, will be necessary. The colour reactions given by the proteids when treated with various reagents were also investigated, and some attempt made to allocate the groups in the molecule characteristic of special reactions; in this field our knowledge, though recently considerably extended, is still far from complete. A study of the gradual decomposition of proteids by hydrolysing agents, both acids and enzymes, resulted in the separation and classification of the non-crystalline derivatives of digestion, aJbumoses, and peptones, and also in the isolation of a number of crystalline amiiio- acids, the best characterised being leucin and tyrosin. In the recent extension of our knowledge of these simpler decomposition products, the work of Kossel and of Emil Fischer stands pre-eminent; the former isolated ■his so-called " hexone bases " arginine, lysine, and histidine, the constitution of all of which has now been definitely established. To Emil I>"ischer we arc indebted both for the isolation of new compounds and for definitely establishing the constitution of products w hich former inve.stigators had only succeeded in separating. The problem of the structure of proteids mav be at- tacked both by analytical and synthetical methods, the latter being dependent on the former, since the simple decomposition products isolated will aiTord a clue as to the materials to be employed in synthesis. Now, although 428 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. the number of these ultimate products identified has been recently much increased, the substances isolated all belong to the class of amino-acids; that is, they con tain the characteristic acid carboxyl group " COOH and the amino group " .\'H2," or a derivati\e of this. It has, however, been shown that in addition to the mono- and di-aniino acids, examples of which were already known, a new class of amino-acids in which the nitrogen is bound up in a ring, is present; as in- stances of these cyclic nitrogen-containing acids and pyrrolidine carboxylic acid, isolated bv Fischer and r<'- CH.,-CH, I " I " presented bv the formula CH2 CH. COOH mav be \^ NH cited, and histidine and tryptophane are other members of this class. The presence of oxy-amino acids among these cleavage products is of interest since these may form a link between carbohydrate and proteid in the animal organism. In all, the identity of about twenty of these products is now established, but the number of these obtained from any one proteid \aries considerably; from the de- composition of casein, the chief proteid present in milk, as many as sixteen of these acids have been isolated, whilst the comparatively simple protamines obtained by Kossel from the sperm of fishes give only three or four of them. These amino-acids form, therefore, the starting point of all attempts at synthesis. In order that the synthesis may be successful, two conditions are requisite; in the first place, the synthetic substance must possess the properties characteristic of the proteids; it should give certain colour-reactions, notably a pink or violet colour, when solutions of copper sulphate and caustic soda are added and known as the " biuret " test; it should be similar in physical properties, and it should be broken doun both by mineral acids and by the proteolytic enzymes giving simple amino-acids. The second con- dition is that the method of synthesis should lead to a product the constitution of which may be easily eluci- dated. Neither of these requirements was fulfilled by the earlier attempts at synthesis; it is true that Curtius as early as 1882 isolated his " biuret base " as the re- sult of the spontaneous decomposition of ethyl glycine, but its constitution was only determined two years ago by its discoverer after it had been shown by Schwarz- schild to be decomposable by the pancreatic enzyme, trypsin. The only systematic attempts at synthesis are those of Emil Fischer, who has succeeded in finding a general method by which long chains of amino-acids may be built up into complicated molecules of undoubted chemical individuality and of determinate structure. The method appears capable of wide application, and con- sists essentially in treating the chloride of a halogen- substituted amino-acid with an amino-acid ester. The resulting ester is saponified, and the halogen atom subsequently removed by treatment with strong aqueous ammonia. This is represented bv the following equations : — CH, CI. COCl-f NH.,. 'CH„ CONH. CH, COO Et — >- CH,, CICONH. CH,. CONH. CH. COO Et — ^ CH.CICONH.CH, CO. NHCHCOOH — >~ CH., NH,. CONH. CH, CONH CH, COOH These condensed amino-acids are termed by their discoverer " peptides," the number of amino-acids coupled up being signified by the prefix di, tri, tetra, &c. Many of the decomposition products of native proteids have been used as the building-stones in this method; glycocoll, alanin, leucin, tyrosin, and several others have been made to react with the chlorides of halogen derixatives of different fatty acids, and a great variety of products have thus been obtained, as many as five acids having been built up into one large molecule. The properties of these polypeptides vary with the radi- cals employed; they show less disposition to crystallise as the number of residues built up increases; they are soluble in water, those produced from optically active acids being most soluble; the}' are precipitated by the re-agents used to precipitate proteids, many give the biuret reaction, and if tyrosin be one of the acids used in their synthesis Millon's reaction is also given. In addition, those built up from tyrosin and leucin are acted upon by trypsin, these acids being split off as in the action of enzymes on proteids. The peptides show, therefore, properties closely analogous to thosL' of the proteids, and the manner in which they are built up furnishes us with valuable evidence as to the probable atomic structure of the proteids themselves. Substances similar to these synthetic polypeptides have now been isolated by P'ischer from the products of hydrolytic decomposition of proteids, and this furnishes strong evidence that the method of combina- tion in these compounds is closely allied to' that in the proteids themselves. The h3'drolysis by enzymes or acids consists essentially in the addition of the elements of water ;md in the subsequent splitting up of the proteid molecule. This decomposition is gradual, and takes place in successive stages, smaller and smaller molecules being split off. \'arious investigators have brought forward different schemes by which this action may be represented; most of these are open to dispute, for much remains to be known as to the exact relation- ships obtaining between these products. The proteid goes into solution in the presence of alkali or acid in the form of alkali or acid-albumen; this is followed by the appearance of albumoses, and at a later stage peptones are detected, all which substances give the biuret test. Much discussion has raged round the num- ber and nature of the albumoses and peptones formed. By some investigators they are classified into two groups, one of which is completely resistant to the lurther action of enzymes, and remains, therefore, as an -"nd product of enzyme digestion; the second group, on the other hand, is readily attacked by these agents. It has for long been known that proteids are much more readily and completely broken down by the action of acids than they are by the action of enz\mes. It has now been shown that although the action of the latter is very much slower, it may be nearly as complete as that of acids. Fischer and Abderhalden carried out a sei ies of experiments in which proteids were digested with pancreatic ferment for as long as seven months; at the end of this period hardly any trace of the biuret reaction was observable in the solution. Since the biuret test is characteristic of both albumoses and pep- tones, it follows that both these substances had disap- peared, and can no longer be regarded as end-products of the action of enzymes, their power of resistance being only one of degree. The solution thus obtained by prolonged pancreatic digestion contained not only the acids already identified, but, in addition, a com- plicated polypeptide, giving a barely perceptible biuret reaction, and decomposed by further hydrolvsis with acids into six already isolated amino-acids. Other observers, notably, Zunz and Pfaundler, had already pointed out that if one endeavours to trace quantitatively the course of proteid decomposition by May, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 429 estimating the amount of nitrogen in the various pro- ducts separated at the different stages, there is from the very earliest period a consideraljlc discrepancy when this is compared with the amount of nitrogen in the original proteid. This must mean that substances are formed which are not detected and isolated by the methods made use of for this purpose, and that a large proportion of soluble nitrogenous products, not giving the biuret re- action, are formed. Pfaundlcr succeeded in showing that these products, if submitted to the action of acid, gave rise to amino-acids, which could then be detected in the solution. These products are, then, similar to the polypeptide now isolated. .'\nother point that has been clearly established is that these amino-acids vary greatly in the ease with which they are split off. Leucin and tyrosin are the two first amino-acids to appear and separate at a compara- tively early stage of digestion. It is true that these acids are more easily detected than many of the others, but careful search has failed to detect the presence of other acids at an equall}' early stage, and in this con- nection it is interesting to note that the synthetic pep- tides built up from these acids are the ones which were found to be attacked bv enzymes. These soluble polypeptides possibly form a kind of resistant nucleus in the proteid molecule. The view that a resistant nucleus remains after various simpler groups have been split off has long been held; its nature has iDeen much debated, and is still unsettled, though the theory that it is a polypeptide-like body finds con- siderable support. We may regard the proteid molecule as built up, therefore, of a large number of amino-acids, the struc- ture of which suffers very little change in this incorpora- tion, so that these acids are again readily split off. The nature of this linking is probably that indicated by Emil Fischer and described above." Certain of these groups appear to offer a more vulnerable point of at- tack on which the hydrolysing agent seizes to begin the demolition of the molecule. This demolition only can proceed gradually, resistance being offered at every stage. The great problem of the method of absorption of proteids from the alimentary canal, of which so little is known and which is yet of such vital importancje, is intimately bound up with the question of proteid chemis- try. We can trace the digestion of the proteid in the alimentary canal and detect there albumose and pep- tone, but in the blood vessel which carries away the products of digestion neither albumose nor peptone can with certainty be detected, and we can detect no in- crease in its proteids as the blood leaves the .ilimentary canal after a meal. The detection of small quantities of albumo.se and peptone in the blood would not be easy, and a slight increa.se of proteid might readily escape obser\ation, for the estimation in such a dilute solution does not permit of extreme accuracy. On the other hand since the breaking down of the proteid is more complete than was at one time supposed, the nitrogenous matter may be absorbed in the form of .some of the.se simpler soluble substances, which have lor so long remained undetected; indet'd, it is found that peptides and amino-acids administered as food, lead ti) an increasetl excretion of urea. Certain feeding experiments have Ixx-n carried out with the object of throwing light on this most difficult and 111 )st fundamental of problems. Li.wi showed that nitrogenous equilibrium mav be maintained in do<.s fed with the crystalline cleavage products resulting'' from the pancreatic digestion of proteids, which no longer give the biuret reaction. The experiments of Abder- halden do not fully support this ; he found that casein and the products of pancreatic proteolysis of casein were equally efficacious as foods; this solution, however, still gave a biuret reaction, and if the diges- tion were carried further by treating the proteid with acid, death resulted if the feeding was continued for long with such a solution. Further development of such work is desirable, for it would be of the very greatest importance if it could be established that the complicated proteid is not an essential food for the maintenance of animal life. Now that the synthesis of the simpler carbohydrates is an accomplished fact and that of the simpler proteids has been brought within the region of probability, the old distinction at one time drawn between plant and animal foods loses much of its force. Plants we know can from the simplest materials, carbonic acid and water, manufacture carbohydrate, whilst their nitro- genous food may be supplied to them in the simple form of nitrate or ammonium salt. Animals, on the other hand, require carbohydrate and proteid to be sup- plied ready-made, some living organism having already accomplished the work of elaboration. It is not so very long since these substances seemed almost re- moved from the possibility of synthesis; it was as if they were divided off by barriers, akin to those that were supposed to separate organic and inorganic substances before the first organic compound had been synthesised in Wohler's laboratory. If now it can be shown that it is merely a question of the form in which the simple food is supplied, and that an assortment of the.se com- paratively simple amino-acids will serve as nitrogenous food, the difference between the complexity of plant and animal food becomes of a much lower degree, and the idea of a synthetic laboratory food no longer is to be regarded as an impossibilitv. ^^^^^^ The Work of Radium. What is the work that is being done by radium as it continues — for 30,000 yeais or more — to shoot out atoms and electrons? Some attempt to give a concrete illustration of its accomplishment has been made bv M. Holzmuller, in continuation of the calculations made bv Dr. Wien. A milligramme of radium shoots out some 29,000,000 negative electrons every second with a speed approximately five-sixths that of light. These are the (i rays. It is also sending out a rays which are particles much more massive, but the speed of which is only one- eighteenth that of light. The amount of work which is thus being done can, of course, only be expressed in "ergs." M. Holzmiiller's calculations take as their starting point that a milligramme of radium bromide is doing \\ork equal to 7^2 ergs a second. But the pure radium in radium bromide is only three-fifths of the whole substance, so that the radium is actuallv doing more work than this; and to cut these calculations down to their smallest possible proportions we arrive ulti- mately at the estimate that a milligramme of radium I)efore it has exhausted all the energy occluded in its atoms will have done some ten billion ergs of work. In other words, it will have done work equal to 100,000 kilogrammetres; and, to make the final mathematical reduction, a gramme of radium, which is a very small crumb of material, exhausts in the course of its life an nus performs her revolution in 224 days i6| hours; and in the case of this planet, and for the purposes of the diagram, 224 days is regarded as being the interval which will bring the planet to its first position of laiuiarv 3. Subsequent positions are shown at intervals of t'ight davs. because, by their selection, they may be compared with the positions of Mercury, the earth, or Mars on the same dates. \'enus makes about iS re- volutions in our vear; and her second revolution begins 436 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. on August 15. She is then represented on the diagram by the open" circle which falls n little behind that of January 3, and is thereafter represented in a similrr manner with tiie new d;ite attached. The earth and Mars are also shown at eight-day intervals after January 3. Jupiter's position on January 3 is on the line drawn from S. (the sun); and this planet reaches the positions indicated on April 1, lune 28, September 24, and December 21. Similarly Saturn's position is shown for January 3, June 28, and December 21; and the directions of Uranus and Xep- tuno are indicated for January 3 and December 21. In order to determine the planets which rise before the sun, the reader must bear in mind that the earth revolves on its axis in the direction represented by the arrow (shown at the date September 24). At sunrise the observer emerges from the shadow area. If the drawing be held in such a position that the earth is between the reader and the sun, and he can read the date without turning his head, he will have a correct exhibit of the relative positions of the sun and planets at that date. In this position, if a planet is on the right of the sun, it evidently rises before him. Should the planet be exactly in line with the earth and sun, as, e.g., in the case of Mercury or \'enus, if the planet is on the near side, it is in inferior conjunction; if it is on the far side, it is in superior conjunction. If it is at or near conjunction, it will be lost in the sun's rays. At sunset the obser^-er is entering the shadow area. When the drawing is held for a given date in the position above described, if the planet is on the left of the sun, it will set after him. In order to familiarise himself with the use of the plot, the reader is recommended to confine his attention to one planet at a time, and trace its movements relative to the earth and sun throughout the year. For example, if he will revolve the drawing until the earth is between him and the sun for the date January 3, he will read the same date attached to Mercury. Being on the right of the sun, he rises be- fore him. If the drawing be revolved until the date February 20 is reached, Mercury will then be on the far side of the sun, i.e., in superior conjunction. For some time prior to and after this date, the planet will be lost in the sun's rays. After this he will be on the left side of the sun, and will, therefore, set after him. He will be in conjunction — alternately superior and inferior — six times during the year on the following days : — February 20, April 5, June 8, August 12, September 24, and November 30. If the earth were stationary there would be twice as many conjunctions as revolutions, i.e., eight; but this number is reduced bv two on account of the revolutions of the earth around the sun. Mercury will be seen to good advantage after May 3, before sunrise when near aphelion. He will also be seen advantageously in the early evening after June 28, when approaching aphelion. The last position in- dicated is December 29, when Mercury will rise before the sun. ^'enus rises a short time before the sun on January 3, and thereafter. She will very slowly approach superior conjunction, which she will reach on February 14. She will be seen satisfactorily in the evening about the middle of June. \"enus will then approach nearer the earth until November 30, when she will be in inferior conjunction. Her dark side will be presented to the earth, and she will be lost in the sun's rays. She will then rise before the sun until the end of the year. Mars will be visible in the evening before July 15, when he will reach conjunction; and will then rise be- fore the sun for the remainder of the year. A New Edition of White's Selborne. By Edward .\. Martix, I-.G.S., author of "A Biblio- graphy of Ciilbcrt White." GiLnERT \VniTi;'s book, of which a new edition is before us, was published in 17S9. Shortly after publication the following remark was made to a nephew of W'hite by Dr. Scrope Beardmore, the Warden of Merton College: " Your uncle has sent into the world a pub- lication with nothing to call attention to it but an ad- vertisement or two in the newspapers, but depend upon it the time will come when very few who buy books will be without it." This prediction has been wonder- fully fulfilled, and in the hundred and seventeen years which have since elapsed there has been an average of one new edition in nearly every year. The new edition which Mr. Charles Morlev has Selborne: View frdin tlie U.inijL roof of Gilbert White's t arranged is called a " naturalist's edition," and from the point of \ievy of the modern systematic naturalist the new arrangement which he has adopted is un- doubtedly justified. The whole of White's book has been cut up and classified under headings such as " Meteorology," " Insects," " Birds," &c. Perhaps I may be pardoned remarking that the idea occurred to me some years ago, but I abandoned it as likely to result in a book quite out of keeping with the spirit of White's work. One cannot deny that ^\'hitc was here and there guilty of inaccuracy, or that his conclusions were sometimes at fault, and for these very reasons each succeeding naturalist who edited the book found it necessary to add annotations correcting where it was necessary. Yet in spite of the fact that editors found this necessary, even in some cases adding notes which, in extent, were at greater length than White's own rc- The Natural History of Selborne. by Gilbert White. Naturalist's Edition, classified by Charles Mcrley. Pages 259, and Index. Cs. net. Elliot Stock. May, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 437 marks, the popularity of the work h.os never waned. If it were merely in respect of its value as a natural history work that it has attained and maintained its hig-h classic status, then we should expect at least to find greater accuracy and greater systematisation in it. Pennant, one of his correspondents, issued valuable natural history works, but these have been quite super- seded by more modern works. Why, then, this pheno- menal success of White's " Selborne "? Certainly not as a natural history book, although in the condition of nature knowledge at the time of publication that may have been then its chief attraction. There is some- thing more in it than mere natural history, and it is this — the soul of the work — which, in the present edi- tion, has perforce been left out of account. We do not recognise White in this re-arrangement. The same feelings do not inspire one in reading this edition. Of necessity the blending of one paragraph into another is absent. There is a disjointedness which grates on one's feelings when one has the original in one's mind. So it has been called wisely, as I think, the natural- ist's edition, although I fear even naturalists will feel that certain explanatory or amending notes would have made it more readable and reliable. Leaving aside, however. White's own personalitv and the charm of the connected series of letters, there are certain ad\aiitag<'s in this re-arrangement which one would not wish to overlook. It was somewhat daring of Mr. Mnrlcy to cut up a classic work as he Cottag;e.s in Selborne Street, raised above the level of the road, which has been lowered by the "fretting down of ages," as in the case of many of the hollow lanes around. has, but at ihe same time tin- ix'sult will be cxtrcmelN uschil to those who, having an edition at hand with the arrangement of the letters as in tiie hook when it left White's hands, desire to know all that the author had to say on some given topic. We have all wasted a good deal of time when wishing to look up some particu- lar passage of White's in not being certain in which letter to find it. In this edition not only are kindred passages brought together, but the marginal references indicate thenumbers of the letters of which they formed poitions. There has been difficulty in allocating certain passages to the headings pro\ided for the chapters. This is referred to in the authoi's preface, and is clear on perusing the book. Probiblyno r ne's airanEenient W(Uild agree with that of another. Mut one would think that the references to the formation of the chalk downs should have been placed with the geological notes, as also those dealing with the theory of an isthmus across the Atlantic, upon which White pours so much scorn. Why, also, is the reference to the letters in which are printed W'hitc's monographs on the Hirundincs, which formerly appeared in the " Philosophical Transactions," not placed imder the heading of " Birds? " One point w^hich is brought out strongly by this edi- tion is that White was before all things a student of birds. .-Mthough the extracts run only into 259 pages in all, no less than 134 pages are given to birds, the subject most nearly approaching to it in extent being meteorology, which claims but 30 pages, after which come the mammals, with 21 pages. Botany has 10 pages, but three of these are scarcely botanical, as they deal with what White calls a matter of domestic economy, namely, the u.se of rushes for making rush- lights, and how the housewives who were careful eked out their scanty incomes. The only other re-arrangement of the letters which has hitherto been attempted is that which was first ac- complished by Sir William Jardine in 1833, in whose edition both serie.s of letters are classified according to date, those to Pennant being interposed amongst others of similar dates to Barrington. This arrange- ment of the letters was followed in later editions bv Captain Thomas Brown in 1833, and Edward Jesse in 1 85 1, but Jardine in 1853 reverted to the original arrangement of the letters. Buckland, however, in 1875 adopted the chronological arrangement of the letters. Now we have a fresh classification under sub- ject headings. It fills a vacant space, and all lovers of Gilbert White will no doubt make an acquaintance with it. It will remain a companion rather than a sub- stitute for the older .uid original arrangement. ,j^^^^^ Artificia^l Rvibies. The synthetic diamond is so small and the expense of making it comparatively so great that it is not likely to compete with the crystal made in Nature's laboratories. That is not quite true, however, of the artificial ruby, which can now be made of a " commercial " size, though examination under a lens will usually reveal its inferiority to the real article. Small crystals of a sili- cate of alumina coloured by bichromate of potash have been made for the last 15 years, and a method has been found of increasing their size by " nursing " them, or, in other words, by keeping the crystal in the mother liquid till it grows larger by aggregation. The small ruby to be " nursed " is placed on a turning-plate, where by means of an oxy-hydrogen blowpip>e it is rai.sed to a temperature of about i,8co deg. Centigrade. Then with a pair of pincers there are added to it successively tiny grains of artificial ruby. If the work is carried on iminterruptedly without losing sight of the crystal dexterous handling makes it easy to get fine crystals, all of whose parts, though not of homogeneous origin, are melted together and recrystalised into a single form, which may be cut like a natural crvstal. One of the difficulties of the work is that the crystals often break while cooling, and one of the defects of these manufactured crystals is the presence of air l)ul)!)les which can be detected by a microscope. 438 KNOWLEDGE & SCIENTIFIC NEWS. [May, 1906. REVIEWS OF BOOKS. ASTRONOMY. " Der Bau des Fixsternsystems" (The Structure of the Stellar Universe, with Special Reference to Photometric Results), by Dr. Hermann Kobold, Braunschweig. F. \'ieweg and Sohn ; 6m. 50., pp. xi. + 256, with 3 plates and 19 figures in the text).— This is Vol. XI. of the " Wisscnschaft " series of monographs on natural science and mathematics, and must not be regarded as a work of imaginative philosophv. It is an exliaustive collection of methods and results connected with the subject of stellar and solar motion, by no means confined to the photometry emphasised in the title. This is fortunate, for the under- lying assumption in the ordinary photometric method is that brightness and distance are in something like inverse ratio as a rule, and to this the known exceptions are so numerous as to throw great suspicion on the method. Some fortv pages are devoted to instruments and methods of ob- servation, the determination of positions, brightness, colour, spectral tvpe, parallax, proper motion, radial velocity, and distribution of stars, with different light-scales, colour- scales, and spectrum classification, very little being omitted. Then come about 120 pages of separate results, similarly divided and equally complete, from Ptolemy and .^1 Sufi to the twentieth century, with photometric comparison of catalogues, distribution of spectral types, a ver\- interesting table of 43 stars, with parallax greater than i-2oth of a second of arc, giving their computed absolute brightness on a scale in which Sirius is represented by :ooo, the sun by 34, Vega and Capella by more than 4,000, and a Crucis bv about 5,000, and a long section devoted to the solar motion, with a chart showing the results of more than a score of different determinations of the apex, including two by the author, the first of which has been shown to be quite unjustified, the second depending on determinations of radial velocity. It must be admitted that nearly all recent work on this subject emphasises the idea that although the solar system is almost certainly moving to- wards a point not ven.- far from the direction of ^'ega, yet the actual result of investigation is far from satis- factory, inasmuch as eacli different set of stars gives a different position for the apex, e.(j., stars of type 1. give a different result from stars of type II., bright stars a different result from faint stars, and so on ; and although it would seem that stars of large proper motion, or large radial velocity should give a better result, since the effect of small systematic errors is relativelv less in their case, vet the material of this character, being at present restricted in quantity, partly nullifies the advantage. Perhaps, when Herr Ristenpart's great catalogue is completed, a dis- cussion of all available material may give a result that will inspire more confidence. The last sixtv pages of the book are devoted to the " Bau des Fixternsystems," and special care, as usual, is taken to refer everything to the Milky Way, as the basis of the most obvious and plausible hypo- theses. Some good illustrations of the nebuls are given in this connection, especially a fine copv of Wolf's photograph of the " .\merica " nebula in Cygnus, which figures as frontispiece to the book. .At the end we find useful tables, one of 56 stars with well-determined parallax, principallv from the work of Gill, Elkin, and Peter, giving the classifi- cation according to Pickering and Vogel, and in some cases the radial velocity, and the other of 307 stars with proper motion greater than half a second of arc ; which is Porter's list of 301 stars (Cincinnati, Publication No. 14), but corrc'cted and revised, with the addition of six more recent discoveries, including the great southern " run- away," Cardoba, Zone V., 243. Then follow a short biblio- graphy, a useful index, and two large charts of the position of the North and South Poles of the proper motions of the 307 stars in the list. As a monograph on the subject, the work is excellent, but no one need adopt any hasty con- clusions from the wealth of material. "A la poursuite d'une ombre." Travaux et Observa- tions de la .Societe Astronomique Flammarion de Mont- pellier. Eclipse totale de Soleil du 30 Aout, 1905. — A young Society, founded only in 1902, with an annual subscription of five shillings (six francs), has been able to send an ex- pedition of ten members to observe the total eclipse of 1905 .August 30, at .Mcala de Chisvert ; a book of nearly a hun- dred pages embodies the result in the form of chatty reports bv Professor Marcel Moye, of Mohtpellier University, one of the secretaries of the Society. Their equipment, as was natural, was far from elaborate, but from the many lines of eclipse work that do not require such equipment, this Society omitted very few, as they carried out on a small scale the careful division of labour now generally associated with a naval detachment under the direction of .Sir Norman Lockyer. In view of the forthcoming volume from the British Astronomical .Association, dealing with the same eclipse, we need not look for anything of unique value in the Montpellier results, and the drawings, as reproduced in the work, have a harsh effect, owing to the too great contrast with the background, suffering much in com- parison with Hansky's 1896 eclipse photograph, also re- produced in the volume. But as evidence of vitality and enthusiasm in a scientific society, we have nothing but praise for the book. BOTANY. The Book of the Rothamsted Experiments, by A. D. Hall, M..V. (John Murray ; los. (id. net.) — To every student of agriculture, irrespective of nationality, the mention of Rothamsted recalls to mind the most extended and varied series of experiments, bearing on every branch of agricul- ture, that has hitherto been, or probably ever will be, attempted. Furthermore, the immense amount of information presented in a concise and methodical manner, representing con- tinuous research extended for over half a centurv', and presented to the world at large, will for all time ser\-e as a model, and furnish a sound starting-point for future in- vestigators. The primary object of the book under consideration is to present to the student the chief points of importance, and generalisations suggested by the investigations alluded to ; also to indicate the scope and aim of the I^othamsted Experi- ment Station. The result is an unqualified success. There is nothing in the book that cannot be grasped by the farmer or horticulturist taking an intelligent interest in his vocation, whereas to the student and expert its pages teem with valu- able first-hand information, and suggestions for future inves- tigation. The entire work is founded on a strictly scientific basis, and deals only with fundamental problems, as indicated by the following extract from the preface : " The farmer who visits Rothamsted must not expect to see demonstrations of the most profitable means of growing this or that crop, but rather to obtain information as to its habits or requirements, which on reflection he can make useful under his own con- ditions." Of exceeding interest is the chapter on the sources of the nitrogen of vegetation ; the researches on this subject con- ducted bv Lawes and Gilbert resulted in clearlv demon- strating that the above-ground green parts of plants did not possess the power of fixing nitrogen ; on the other hand these experimenters failed to demonstrate the fact that free nitrogen was fixed bv bacteria present in the nodules on the roots of leguminous plants. This, howe\-er, was not so much due to the fault of the investigators concerned, as to the general apathy towards scientific research in this coun- trv. If the necessarv knowledge had been forthcoming it would have been utilized. This gap, bearing on bacterio- logical work has, so far as Rothamsted is concerned, been bridged by the present Director. The generally accepted idea that whole meal of wheat grain is the most nutritive food is fully dealt with, and shown to be wrong. From scattered remarks it is gathered that an excess of nitrogenous manure favours the attack of fungus parasites. A verv interesting biographical sketch of .Sir John Bennet Lawes and Sir Joseph Henry Gilbert, the founders of the Rothamsted Station, is given. CHEMISTRY. Qualitative Chemical Analysis (Organic and Inorganic), by F. Mollwo Perkin, Fh-D. (Longmans. Green cS: Co. ; vi. -}- 308 pp., 5i + 85, 4s., 1905). — The author, who recognises the fact so familiar to teachers of chemistry that students too often May, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 439 completely separate their theoretical knowledge from their laborator}' experience, has endeavoured in this manual of qualitative chemical analysis to supplement the practical in- structions by sufficient explanatory data to arouse in the learner an intelligent interest in the operations under discus- sion. In these theoretical explanations the author has made judicious use of the ionic theory, employing it where the earlier views are incomplete or misleading, but retaining the older mode of representing double decompositions when this formulation indicates with sufficient accuracy the reactions taking place in the various analytical tests. The chapter on reactions in solutions and the paragraph relating to the solubility of magnesium hydroxide in ammonium chloride are cases in point. The inorganic section of the book deals very fully with the reactions of the ordinary metals and acids and contains also the distinctive tests of certain rarer metals and less common acids. The author states in the prefaces to both editions of the work that only those reactions are included which have been experimentally verified. At the risk of adding to this practical revision, we venture to suggest a few instances in which a little additional informa- tion might be imparted without materially increasing the size of the volume. Among the tests for bisnuith no mention is made of the action of reducing agents; the interaction with alkaline stannites is, however, of some interest, having been recently the subject of a controversy concerning the alleged existence of bismuth suboxide. The statement on p.6g that " the solutions [of chromium salts| are violet or green depending on their concentration " does not sufficiently take into account the effect of tempera- ture on the colour and constitution of these dissolved salts, and of the tendency for the cation Cr to form complex ions with certain anions, such as .SO4 for example. Our experience is that the separation of the sulphides of manganese and zinc from those of nickel and cobalt by means of cold dilute hydrochloric acid is not always reliable, and hence it might be well to give at least a brief reference to the alternative method in which the four sulphides are dissolved simultaneously, the separation being then effected by successive treatment with caustic soda, hydrochloric acid, ammonium acetate, and sulphuretted hydrogen. The acidified permanganate process for detecting chlorides in presence of bromides and iodides is a useful alternative method to those indicated in the text, and the only distinctive test given for bicarbonates might be supplemented by a reference to the behaviour of these substances towards phenolphthalein or mercuric chloride. The organic section contains a useful chapter on " elemen- tary " organic analysis in which a note should be introduced pointing out the danger of employing the sodium or potassium test for nitrogen with nitro-compounds of the picric acid type. The remaining chapters deal with the reactions of representative examples of the chief groups of organic dorivati\es. The sections on alkaloids, carbohy- drates, and organic acids merit special mention as the range of examples is very extensive, and many quite modern tests have been incorporated. Whenever possible, these organic reactions have been tabulated, a system which facilitates comparison and tends to render the practical work more systematic. Full particulars for llie iircparalion of the reagents re- quired in both inorganic and organic sections are given in the appendix. Although a few trivial clerical errors still persist {c.(j. pp. 184, 210), the present edition bears the marks of careful revision, and the author is to be congratulated on the large amoimt of useful information which he has condensed into a conveniint bulk. On this account the work may be re- garded not only as an up-to-date laboratory manual, but also as a serviceable book of reference on analytical chemisliy. ETHNOLOOY. The Twenty-Third Annual Kcport of the Bureau of American Ethnolo) ; Dec. N. 21° 5'. May 31, R.A. 5'' 27"'; Dec. N, 24"' o') is an evening star in Taurus, setting about 9.20 p.m. throughout the month. The planet may be observed shortly after sunset looking to the north-west, but he does not appear very bright, and is not suited for observation in small telescopes as his apparent diameter is only 3"-8. On the evei ing of the 18th he appears in the sky about i^ north of Jupit:r. Jupiter (May i, R.A.4''32"> ; Dec. N. 21'^ 28'; May 31 R.A. 5h !"> ; Dec. N. 22° 22') is only available for obser- vation for a short time after sunset, and after this month will not again be observable as an evening star until Sep- tember. The planet appears in too bright a part of the sky for the satellites to be easily observed. During the early part of May the three most conspicu- ous planets will appear close together and near the ist magnitude star Aldebaran (a Tauri), which, though not a matter of real astronomical interest, forms a rather un- usual appearance in the evening sky. The diagram shows the positions on May 11, when the planets are all near together, \'enus being the brightest and about 1° to the north of Jupiter whilst Mars is feebly visible about 3'-' away. 21, and Mars (?, The planets set about half past nine, and the moon, which is full on the Stb, will be rising in the east. Saturn (May i, R.A. 22'' 58"' ; Dec. S. 8° 23'. May 31, R.A. 23'' 6"^ ; Dec. S. 7 ' 45') is a morning star, rising about 2 a.m. near the middle of the month. The planet is situated in Aquarius. Uranus (May 15, R.A. 18';' 35'"; Dec. S. 23° 31') rises about 11 p.m. near the middle of the month. The planet is badly placed for observation, as he is situated low down in Saggittarius. Neptune (May 15, R.A. 6i> 37'"; Dec. N. 22° 17') is observable in the north-west portion of the evening sky during the early part of the month; on the 15th the planet sets about 11 p.m. Meteor Showers : — The principal shower during May is the Aquarids. This may be looked for between May i to 6 ; the radiant being in R.A. 22'' 32" Dec. S. 2°, near the star ,, Aquarii. Telescopic Orjects: — Double Stars. — Librae, XIV. *" 46", S. 15° 39', mags. 3, 6 ; separation 230" ; very wide pair. a Corona", XVI.h ii", N. 34' 8', mags. 6, 6i ; separa- tion 4"-6 ; binary. a Herculis, XVII.'' id", N. 14° 30', mags. 2i, 6 ; separation 4"-6. Very pretty double, with good contrast of colours, the brighter component being orange, the other blue. 5 Herculis XML" ii", N. 24^ 57', mags. 3, 8 ; separa- tion 17". Clusters. — M13 (cluster in Hercules) situated about I the distance from •,, to j- Herculis, and is just visible to the naked eye. It is a globular cluster, and with a 3 or 4 inch telescope the outlying parts of the cluster can be resolved into a conglomeration of stars. 443 KDooiledge & SeleDtifie fleuis A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. 19. [new series.] JUNE; 1906. SIXPENCE NET. CONTENTS See page Vll. Astronomical Photography. Hints to Amateurs Regarding Apparatus and Methods of Working. By Alexander Smith. III. — Development of Plates. There arc no operations in connection with photo- y^raphy which admit of such varied methods ol treat- ment as the development of dry plates. When these were first introduced, the available developing- agencies were confined to pyrogallic acid and ferrous oxalate of potash, but year after year has added to the number, and at the present time a beginner is well nigh be- wildered with the variety of formuku which he finds set down for his g-uidance in modern photographic text- books. In addition to the long list of v\hat may be regarded as standard solutions, platemakers issue special formulae, which may presumably be supposed to g-ive better results than any other for their particular brand of plates, while the fact remains that for all ordinarv purposes a g^ood standard solution will satis- factorily develop almost any reliable bromide of silver plate on the market. Many workers confine themselves to one make of plate, which they develop with a favourite formula, and, where the results are all that could be dt sired, the best advice that could be given is toadiiere to them, as they become acquainted by experi- ence with all their little peculiarities, which they are able to turn to the best advantage. It is not so much a question of using any special developer for the plates of any particular maker, as of varying the details of treat- ment for different classes of subjects. Those engaged at astronomical work have to deal with objects of a very diversified character — from the noonday sun to the faintest class of nebuhe. In the one case the result aimed at is to obtain detail on a brilliantly lighted sur- face, and in the other the outlines of the merest trace of luminosity projected on a very slightly darker ba<'k- ground. For |MiotogTaphs of tlu- solar image a slow plate should, :is already indicated, always be seUcled, and the same remark applies to lunar and planetar}' work where the driving; arrangements admit of giving the requisite exposure. A developer made up to any standard formula may be employed, but with strontjiy lighted subjects a weak solution will be found to give more satisfactory results than one of normal strength, the plate being: allowed to lie a proportionately longer time in the bath, .^fter carrying out many experiments the writer gives preference to a glycin developer, which has many excellent properties. It is always ready for use with the simple addition of water, and the same solution may be used repeatedly. It does not stain the hands, has no injurious effect on the skin, and keeps indefinitely. It admits of great latitude in exposure, and for all scientific work where it is desired to secure soft and delicate detail it is unsurpassed. It may be used with equal success for the development of nega- tives, lantern slides, or gas-light papers. It does not, however, possess the vigour of pyrogallic acid or metol, and, consequently, the duration of exposure should always be ample, but, on the other hand, a satisfactory negative can be quite readily obtained, although the normal exposure has been very greatly increased. The point to be kept in view is that the developing agent must be of a suitable strength to take up tlie work where the action of light left off, and if an exposure. of 10 or 20 times the normal amount has been given, a satisfactory negative can be quite readily obtained with a glycin developer by employing a diluted, or, what is, perhaps, more preferable, an old solution which has previously developed several plates. Developing agents, such as pyrogallic acid, do not admit of the same lati- tude in exposure, and, if toned down by the addition of bromide, the effect is hard and delicate detail is lost. The following formula, which the writer has used for a ninnber of years, can be confidently recommended : — Water ... ... 18 ounces. .■sulphite of Soda i,ogo grains. Potash Carbonate 2,270 ,, (ilvcin ... ... 1 oz. bottle. Dissolve in hot water in the order given. When cold the solution should be filtered and put into well- stoppered bottles. For use, add three ounces of water to one of the concentrated solution for ordinary work, and about five ounces of water for lantern slides or gas- lig-ht papers. Certain brands of the latter require the addition of a little bromide, but for other purpo.ses it mav be dispensed with, or, at all events, used verv sparingly. -Solutions which have become slower in action after developing a few plates should not be thrown away, as these may be afterwards utilised in cases where the normal exposure can be readily in- creased, and, as a practical illiistration of the keeping 444 KNOWLEDGE & SCIENTIFIC NEWS. [June, 1906. qualities of the developer, it may be pointed out that, with the exception of the phototjraphs of \'cnus, all the plates recjuired to ])roduce the necessary enlargements for the lunar and planetary illustrations accompanying the pre\ ioas paper were developed with a solution which had been several times used 18 months previously. In cases where it is desired to secure delicate detail on a plate which has been exposed to a brilliant light, such as that of the sun's disc, and also in cases where the object presents strong contrasts, the plate should be kept in a very weak solution until a faint image is just visible, which will probably require an hour or more. The strength of the developer may then be gradu- ally increased, the requisite amount of density being finally obtained by using a bath of normal strength. The weak solution may be conveniently kept in an old- fashioned collodion dipping bath fitted with a light-proof cover, and afterwards transferred to the usual develop- ing dish, and treated as described. It must be kept in view that no amount of soaking will bring out detail on a plate which has been under-exposed. The exposure in all cases should be ample, and there is, consequently, behind the developer, a reserve of stored up energy, which can be brought into action as required. With a negative full of detail which is too delicate for the purposes of reproduction, the contrast between the ' high lights " and " shadows " may be increased by taking a positive from the neg-ative by contact or by the camera, a much longer exposure than usual being given to a correspondingly weaker light. On the other hand, where less contrast is required, the light is in- creased and the exposure reduced. To obtain photographs of faint stars the exposure necessary is so protracted that the methods employed must be such as to secure impressions of the largest number on a given area of the plate in the shortest time, but in the case of stars and diffused nebulosities showing little detail in the shape of structure nothing is sacrificed by having recourse to methods which admit of the exposure being largely reduced at the expense of getting harder effects. For such subjects the most rapid brand oi plate should, therefore, be used in con- junction with a vigorous developer. Metol will be found to give cleaner negatives than pyrogallic acid, but if used frequently it sets up an irritating action on the skin, unless the precaution is taken beforehand of rubbing the fingers with vaseline. Tlie following formula has been found to give good results : — Water 20 ounces. Metol Sulphite of Soda Carbonate of Soda (crystals) Bromide of Potassium 75 grains. 10 drams. 14 M 'r;inciscan earthquakes of this vear, as well as (il lour disturbances occin'ring in 1905. Iwo diagi.iTus /P£ rOR EMPTYING THE JACKET fS INOENTtO HERE TO RECEI V£ BURN En BONSF.NS BUfiNEH VESSEL WITH WATEH FOB RECEI Vine CAPTURES .■rp|);ir.ilus lor <':ipluring minute inst-cls, the ,aclion ol which is s-.'iMi in Ihe .iccompans ing section di.a- grani. The hollow nu-t;il cone is boiiiidird l)\' a water jackc^t ; on the open base of the iiuerted cone rests a lra\' madi- of \\ ire gauze, designed to carry moss or any other materi;d which forms the natur.al harboiu"- ing quarters of small in.sects. If the v.ater in the jacket is maintained at a 1emper.il\ue of about 70" Centigrade the tiny denizens prefer to quit tlu- moss, but since no footing is obl.ain.able along the sloping .'ides of the cone thev f.ill into the glass rec<-ptacle placed at the apical end of the cone. From there they can be transferred to a dis.secting microscope, if re- quired, for idcntilication or examination. Mr. Stanlev Ciardiner and Mr. 11. I'. Tliomasset's fine series of enlarged photographs of the vegetation of the Seychelles indicated Ihe sharply divisibU> character of the llor.i due to soil characteristics. The Stellar Universe. F.. CoKK, |-.R..\.S., M.R.1..\. TiiA'r our visible imiverse is limited in extent there is .abundant evidence to show. The number ol stars visi- ble to the naked eve is not only comparatively small, hut absolutely so; and the mmiber which will .appear on the |ihotog-raphic charts of the sky, now in progress, will probably not exceed 100 millions. .And even this l.irge muiibir is comparatively sm.all. The richest man in the world is said to possess as many sovereig'ns; and in a ten-.acre field of ripe oats the number of grains of ■ orn probrdilv exceeds the number of the visible stars.* Taking the popidation of the earth at 1,500 millions, we ha\e tin- rem.-irlsable f.aet that for e\erv star in the sky there .ire 15 hum.-m beings living on our little globe. The mmiber of stars visible to the n:iked eye has been \.iriouslv estimated. The photometric measures made at Harvard Observatory show the following; figures : — Lender magnitude 2, 38 stars; under 3.0, t^q; under 4.0, 317; under 5.0, 1,020; and under 6.0, 2,863; •'>tal 4,339 to the (ilh magnitiule. The coellieient of increase for each m.ignilude is .about 3; th.il is, the tot:d number down to any given magnitud<' is about 3 times the mnnber of all stars brighter than that magnitude. Pro- lessor Xewcomb thinks that there is no evidence of de- crease in this coeHieienl down to the loth magfnitude. Ihit a dimimition in the r.ate of increase must set in 'iimcwherc lielow the 10th m.'ignitude, for otherwise tile numlit-r ol the xisilile stars would be considerably greater than it ;ictiially is. T.aking the total number of ^^tars to magnitude ().o as 4,339, and allowing a factor of 3 for the total number to each magnitude below this, 1 lind that the total number down to the 15th magnitude 'lould be .about S3 millions, to the Idth magnitude .about 23(1 millions, and to the i7lh magnitude — about the fainti'-t \isiblein the great ^■erkes telescope — about 7()S millions. It is exitlenl, therefore, that there must be a diminution, or " thinning' out," of the visible stars :it some point in space. This diminution in the increase probablv begins with stars of the loth or nth magnitude. \ow what is the cause of this decrease in number as the stars become fainter? Is it due to an .actual decrease in number as we approach the limits of the visible unixerse, or is it caused by an extinction of light in the ether of space? The latter seems im- prob.ible, Inr Professor Seeligcr finds that stars of the I Ilh and 1 1 ', magnitude are comparatively few- in nimi- liri 111:11 the poles of the .Milky Way, but are very nunnrous in tlie C.il.ixy itself. This is al.so true for f.iinler stars, such .is those seen by Sir William llersehel in his "gages." Photographs give similar results. Dr. Roberts' photograph of the Milky Way in Cvgfiuis shows about 8,500 stars to the square degree, w hile a photogTaph taken near the North Cialactic pole shows only T78 stars to the square degree, the average for the whole sky being about 2,300. It seems riasonable, therefore, to conclude that if faint stars arc .ipparentb few in number near the poles of the Milky 'This I have foiimi hv .ictii.il e.sperimcnt o\\ llic niimlier of grains on .1 squnro foot. 450 KNOWLEDGE & SCIENTIFIC NEWS. [June, igo6. Way, the real reason is that the stars are not there, and that in this region, at least, there is a real " thinning out " of the stars at a certain distance from the earth. It is clear that if absorption of liifht by the ether had any real, or, at lea.st, appreciable, effect, it would have the same effect in the direction of the Milky Way a.s in that of the Galactic poles. We must, therefore, con- chide that the paucity of stars near the poles of the Milky Way indicates that the stars are really few in number in that direction, and that here, at least, the visible universe of stars is limited. And it seems hisjhly [irobablc, and, indeed, we may say certain, that even in the direction of the Milky Way itself the stars thin out beyond a certain distance, and do not extend in- definitely into space, for if they did, the Milky Way would be much brighter than it is. Now let us consider what is the probable extent of the visible universe. The faintest stars visible on photo- graphs are probably about the i8th magnitude; that is, about one magnitude fainter than the faintest visible in the Yerkes telescope. .Assuming this magnitude, and taking the sun's stellar magnitude as — 26.5, I find that to reduce the sun's brightness to that of these faint stars it should be removed to a distance repre- sented by about 12,500 years of light travel. The sun, if placed at the distance of Sirius (parallax = o".37), would shine as a star of about 2.22 magnitude, or 3.8 magnitudes fainter than Sirius appears to us. From this it follows that Sirius is about 33 times brighter than the sun. Sirius might, therefore, be removed to 5.75 times (v 33) its present distance and still shine as a star of 2.22 magnitude; and to reduce it to a star of the i8th magnitude it should be removed to 8,241 times its pre- sent distance. This would represent a light journey of about 72,000 years. If, therefore, any of the i8th magnitude stars in the Milky Way are suns similar to Sirius, that is, of the same size and intrinsic luminosity, they may lie at a distance of 72,000 years of light travel from the earth. That is, provided that light suffers no extinction in craversing this vast distance. .\nd if similar to our sun, they may be at a distance of over 12,000 years' journey for light. There seems to be evidence, however, that the greater portion of the light of the Milky Way does not come from these faint stars, but from stars considerably brighter. Mr. C. Easton finds from an examination of a photographic plate of a very brilliant region of the Milky Way to the south of the bright star 7 Cygni (a region including 25 Cygni), that about half the total light of the Milky Way in this region comes from stars of the gth to the i2lh magnitude. From this he con- cludes that neither the bright telescopic stars {6th to qth magnitude) nor the very faint stars (12th to 14th magnitude) have any great influence in producing the light of the Galaxy. From an investigation of a much fainter portion of the Milky Way he finds the same result.* This agrees with my own computations of the total brightness of starlight, which show that the maximum amount of light comes from stars of the gth to I2lh magnitude, t From further investigation Easton thinks it " extremely probable that the great majority of the fainter stars of the Milky Way — so far as their existence is revealed to us by photography or direct vision — are not much more distant from us than the stars of the gth or 10th magnitude, at least, in the regions to which our researches have extended." { Professor Newcomb thinks that there is evidence to show that the stars of the Milky Way are probably situated at a distance between 100 million and 2co million times the sun's distance from the earth. These distances correspond to i,57g and 3,i5g years of light travel. Placed at the greater of these distances, I find that the sun would be reduced in brightness to a star of the 15th magnitude. There seems to be evidence that the faint stars of the Milk-y Way have spectra of the Sirian type. Sup- posing, with Easton, that the fainter stars of the Milky Way are of the 12th magnitude, and, further, that they are comparaijie with .Sirius in size and brightness, I find that their distance would be represented by about 4,600 years of light travel. But Sirius is, perhaps, a larger body than the average Galactic star. Its mass is about two and a half times the mass of the sun, and its brightness about 33 times greater. Possibly the stars of the Milky Way may be much smaller. Pro- fessor Kapteyn finds from an investigation of the probable distances and brightness of a number of stars of various magnitudes that in a volume of space con- taining two millions of stars of the same luminosity as the sun there would probably be about half a million brighter than the sun, and about 12^ millions of smaller luminosity; that is, out of a total of 15 millions of stars, about 12^ millions would be smaller than our sun. To reduce the sun to the brightness of a star of the 1 2th magnitude it should be removed to a distance of about 7go "light years." To reduce the following stars to the 12th magnitude they should be removed to the distances represented by the light years given in the fifth column : — * " Knowledge." July, 1903. " K.NOWLEDGE," August, iSgj. t "Knowledge," August, 1901. Magni- tude. Distance. Distance to wliich Star ST.Ml. Parallax. Light should be moved to reduce Years. its light to r2th magnitude. " Light years. Sirius.. -158 037 8-8 4600 a Centauri o-oG 0-75 4-34 io85 Capella 0 21 0-oS 40-7 9300 Procyon 0-48 0325 10 2030 a Aquilas 089 0 231 14-1 2360 Aldebaran . . I -05 0.107 30'4 4650 ■q Cassiopeix' . . 3-64 0-I54 211 1000 T Ceti .. 3-65 0-31 105 500 70 Ophiuchi 4-07 0-i6 203 794 0, Eridani 4-48 o-i66 iq C51 S Equulii 4-61 0 071 46 1416 e Indi .. 4-74 0-28 II 6 309 1830, Groom- bridge 6-47 0-I5 21-7 278 La'ande, 21,185. 1 7-60 0-344 9-4 72 Kruger, 60 9 0-271 12 48 Omitting the last two stars, which seem to be smiill bodies comparatively near the earth, we see that the distances of the others would range from 278 to 9,300 years, if all were reduced in light to a star of the 12th magnitude. The average of these is 2,g2i light years. As these stars are of various sizes and brightness — their " relative brightness " compared with the sun ranging from 0.122 to 128.33*— we may, perhaps, as- sume that they represent nearly all classes of stars, and that the average distance of 12th magnitude stars is about 3,000 light years. If we assume that the stars of the Milky Way are much smaller than Sirius, say one-half the mass of the sun, or one-fifth of the mass of Sirius, I find that the distance of 12th magnitude stars would be — if of the • See my paper on The licUtive Brightness of Stars in Monthly Notices, R.A.S,, Janii.-iry, 1905. June, igo6.j KNOWLEDGE & SCIENTIEIC NEWS. 451 same density and surface luminosity as Sirius — about 2,700 " lis^ht years." Let us assume with Nevvcomb that the outer boundary ol the Milky Way is at about 3,000 light years, and see what average distance this will give between each pair of stars, on the supposition of an equal distribution of stars in a globular space. We know, of course, that the visible stars are not cqually distributed , but the computation will give the average distance between any two adjacent stars. As- suming a total of 100 millions, and that each star is placed at the anglt of a tetrahedron,* I find that the average distance between two stars would be alsout 21.24 I'.i^^ht years. This corresponds to a parallax of o". 153. Now I find that the average parallax of 20 stars, for which a fairly reliable parallax has been found is o''.247. If we exclude those stars with a parallax of over o''.3 — which may, perhaps, be considered as ex- ceptionally close to our system — we have 13 stars with an average parallax of o". 155. From a consideration of the proper motions of two groups of stars, one of 206 stars of mean magnitude 5.7, and mean proper motion of c".3i per annum, and another of igg stars of mean magnitude 8.1, and mean proper motion of o''.304, Mr. J. G. Porter finds " the average parallactic motion " of all the stars to be o''. 185; that is, the annual apparent motion due to the .<;un's motion in space. Taking this annual motion as four radii of the earth's orbit, that is, four times the sun's distance from, the earth — a quantity probably near the truth — the mean paridlax of the stars con- sidered would be o".o46, or about 70 years' journey for light. But judging from their magnitude these stars would not be among our nearest neighbours in space. With a distance of 21.25 "ght years between two stars at a distance of 3,000 light years from the earth, I find that the apparent distance between such stars in the Milky Way would be about 24 minutes of arc, and as the faint stars in the Galaxy are, on an average, much closer than this, it seems highly probable that the stars composing the Milky Way are much nearer to each other than a distance of 21 light years, and this the crowded appear;mcc of the Galaxy would lead us to suppose. If wc take the average width of the Milky Way as 20", I find that tlie volume of space contained by lines drawn from ihi' eye to the edges of the Galaxy is about o 1767 of the volume of the whole sphere. Hence, with an equal distribution of stars, the Milky Way should contain about 17A- millions of stars. Now Dr. Roberts' photograph in Cygnus shows about 8,500 stars to the square degree. This would give a total of about 61 millions for the whole of the Milky Way. Rut as this is rather a rich part of the Galaxy the total may not exceed 40 or 50 millions; that is, two or three times that due to an equal distribution of stars. This agrees with some experiments made by Mr. (iavin j. I?urns, who finds that the average luminositv of the Milky Way is from two to three times greater than that of the rest of the sky. | Assuming that the Milky Way contains a total of 50 millions of stars, and that its limits lie between 1,500 and 3,000 " light years," I find that its volume would be about 0.1546 of the sphere having a radius of 3,000 light \ears. This would give an average distance be- tween two adjacent stars of 14.31) I'.glit years. On this hypothesis tlic Milky W.iy would have a considerably * If s he tlic side (if a telrtitlicdron, its volume is S3 — V 2. 12 ^ f .lsti:^/'li\siuil Jotii-ii.tl, (October, igo2. greater extension in the line of sight than at right angles to that line. If we suppose that its thickness in the line of sight does not on the average exceed its apparent thickness; that is, that its cross section is roughly circular, and assuming that its mean distance is about 2,300 light years, I find that its diameter would be about 800 light years, its nearest and its farthest parts being at about 1,900 and 2,700 light years re- spectively. In this case the average distance between the component stars w'ould be about 10.7 light years. In the globular cluster u Centauri, an enumeration made from photographs by Professor and Mrs. Bailly gives a total of 6,389 stars on an area of about 30 minutes square. T his gives 25,556 stars to the square degree, and if the distance of u Centauri is at all com- parable with that of the Milky Way its component stars must be much closer than in any part of the Galaxy. The same may be said of the smaller Magellanic Cloud, which has about 28,000 stars to the square degree. E!aston thinks that the stellar universe is of " a fairly thick lens shape filled with stars which are much more closely congregated near the edges than near the centre of the lens." Professor Newcomb's views are some- what similar. But this is returning to Sir W'illiam Herschel's " disc theory," and it seems doubtful whether such a conclusion is warranted by the evidence. As is well known, this disc theory was abandoned by Herschel himself in his later writings. I have never seen any answer to the argument against the disc theory advanced by me in " The \'isible Universe " (no. 241, 242). The argument is as follows : — As the thickness of Herschel's supposed disc extends on both sides of the earth beyond the theoretical distance of stars of the gth magnitude, the stars of this magnitude should be as numerous in the direction of the Galactic poles as in the direction of the Milky Way itself. But this is not the case. Argelander's maps show that gth magni- tude stars are more numerous in the Milky Way than at the Northern Galactic pole in the ratio of 2^ to i. Kven the stars visible to the naked eye show a marked tendencv to aggregation on the Milkv Way, and liaston finds that the taintest siars of Argelanders' catalogue — about gi magnitude — " present, by the manner in which they are distributed, a remarkable correspondence w'ith the luminous and obscure spots of the Milky Wa\\" These facts seem to be inconsistent with the disc theorj' as originally propounded by Herschel. From the evi- dence quoted above it seems evident that if the stellar system is in any way shaped like " a thick lens " there must he a considerable crowding of stars along the edge of the disc; that is, in the direction of the Milky Way. Stru\e's modification of the " disc theory," namely, a disc of a certain thickness, but of infinite, or, at least, indeterminate, diameter, seems an improbable hypo- thesis, and one not in agreement with observed facts. I-lven on this theory our sidereal system is supposed to be limited in the direction of the (Galactic poles. If .Struve's theory were accepted we should also be obliged to accept his hypothesis of the extinction of light in the ether; for otherwise the Milky Way would be much brighter than it is. With an infinite extension, the Galaxy would shine with the brightness of the sun. The comparatively feeble gleam of the Milky Way on even the clearest nights should, I think, be sullicient to convince the thoughtful observer that its light is rw/ due to a vastly extended stratum of stars. Fven Sir John Herschel's reflecting telescope of i8i inches aperture (now far surpassed in space-penetrating power ijy modern instruments) sufficed in some places to show the eoniponent stars of the Milky Way on a /'/lc., has been inserted; at a distance it resembles a flag somewhat." We reproduce one of Mr. Roth's photographs of message-sticks. There are many other forms, but these appear to be as characteristic as any. 456 KNOWLEDGE & SCIENTIEIC NEWS. IJlNE, 1906. Photography. Pure and Applied. By Chapman Jones, F.I.C, F.C.S., ice. Specially Scnsi/iscd Plates. — A little more than a year a.ifo I referred to the advantaifcs of bathing plates in the prepared dye solution in order to increase their sensiti\eness to yreen, yellow, and red, as compared with the incorporation of the sensitisintf substance with the emul.sion before the phites are coated, and stated that Messrs. Sanger-Shepherd and Co. were [)rcparinii' to issue a bathed plate commercially. The dilliculty, it not the impossibility, of preparintr bathed plates in lari^e quantities that shall be uniform in the various liatches and remain without appreciable chang^e for a sullicient time to render them practically available for general work, has caused this firm to issue an emulsion ^;e^sitised plate instead. The " Sanger-Shepherd " plate is of excellent C|ualify, moderately rapid, and shows a very even sensitiveness to red, green, and yellow, when tested by daylig-ht. In this it is much superior to many plates si)ecially sensitised for red or for the three colours named. The proportion of red sensitiveness to total sensitiveness in the sample I have examined is somewhere ;ibout four times as great as in the plates that Messrs. .Sanger-Shepherd and Co. used to sup[)ly for use in their process of colour photography, anil this indicates a very great improvement. Plates bathed with pinachrome and with pinacyanol have recently been put on the market by Messrs. Wratten and W'ainwrightj and the makers state that they are of very great general sensitiveness, and that the sensitiveness of one of them at least to yellow light is almost equal to its sensitiveness to blue light. I have not seen a statement as to the sensitiveness to red of either, thoug'h they are claimed to be specially good in this matter, and presumably with very gocxl reason. for those who desire bathed plates without the trouble of treating them, Messrs. Penrose and Co. announce that they are prepared to sensitise plates by bathing to order, using either of the following dyes : — ortiiochrome T for general colour sensitiveness, pina- chrome for general sen.sitiveness with a high speed, pinacyanol for red sensitiveness and high speed, dicya- nine for sensitiveness to red extending to the less re- trangible colour, and also, for green sensitiveness, tetrabromfluorescein, diiodofluorescein, homocol, and ethyl red. The plates will keep in g(M)d condition for two or three weeks. This will doubtless be a great con- venience to many workers, and they will have the ad- vantage of knowing exactly what sensitiser has been employed. On the other hand there are advantag-es sometimes in the use of n;ixed sensitisers as exempliiled in commercial plates, and the experimental work that guides manufacturers is not generally available. lyie Choice of Sensitisers -for Tied Light. — There ha\-e lately been introduced several sensitisers for red in addition to the two or three that have been known for many years. Mr. \V. A. Scoble has recently com- municated to the Royal Photographic Society the results of his comparative experiments with all that are prac- tically available, nine dyes in all. For getting sensi- tiveness to the extreme red ])inacyanol is effective as far as A, dicyanine nearly as far, while alizarine blue S sensitises into the infra red, bnl h.is the disadvantage of being, as others have found it, uncertain. In con- sequence of this dilliculty be has selected pinacyanol as the best for his work, though his observations on the colour changes of alizarine blue S when in solution seem to go far towards eliminating the uncertainty of its effects.* A noteworthy statement in his comnnniica- tion is that he found no appreciable difference whether he exposed the plates wet soon after being bathed, or after being dried. The use of the undried plates saves not only the time and trouble of drying, but the risk of deterioration, which is considerable with some sensi- tisers. Will Specially Coloured Sensitised Plates be much ap- preciated?— It cannot but occur to tho.se who take an interest in the matter to ask themselves whether the facilities referred to in the two previous sections will meet with due appreciation. If I had to answer this question I should reply in the negative. Plates sensi- tised for green have been on the market for about twenty years, their advantages have been incessantly pro- claimed, but even to-day they are very rarely properly used, and it is often necessary to dra\v attention to their (■xistoni-e. I should not be surprised if ten years hence red sensitised plates will still stand in need of special pleading so far as general photography is concerned. It is the needs of the trade in the practise of three- colour work that has been the chief incentive in the investigations connected with red sensitisers. The \ast majority of photographers probably do not know that when they photograph a dark slated roof with a ridge of light red tiles on it, the tiles come out darker than the slates even when an " orthochromatic " plate is used w ith a screen. The want of discrimination on the part (jf photographers and those who look at their pro- ductions is the cause of the absence of a demand for correct representations, and no demand, of course, means no supply. Improvements in red sensitiveness will be quickly utilised by spectro.scopists because in theii' work nothing can take its place; in microscopy and certain other scientific work they will slowly find appreciation; but for general purposes I fear that they will remain neglected except by an enthusiastic few. It must be admitted that it needs enthusiasm to make the sacrifices that must be made if the possibilities of suih plates are to be fully taken advantage of. And certainly there is a great deal to be said in favour of the facilities that at present are incompatible with red sensitiveness. Dark Rooms. — Photographers when working away from home, whether in the British Isles, on the Con- tinent, or even in the more remote parts of the world, will find " .V Directory of Public Dark Rooms," pub- lished by Messrs. Dawbarn and W'ard at 3d., of much use. It contains nearly three thousand entries. But if anvone should happen to go on tour without such information, he should look in likely places for a bold dark blue Maltese cross six inches square on a rather larger card or enamelled iron sheet. Where\er this sign is displayed there is a dark room available, and also a copy of the directory of dark rooms that may be consulted by visitors. This arrangement is fairly well established, for it has been in force some four or five years, and in order to perfect it, the publishers would bi- grateful to receive any intimations of errors or omissions that are noticed in the directory. Notice. — The Royal Photographic Society has arranged an exhibition of works by the members of the Birmingham Photographic Society, at 66, Russell Square, which will remain open to the public daily till the i6th inst. • Since writing this Mr. Scoble has personally assured me that by oljserving the precautions as to colour changes given in his paper, he finds that the uncertainties hitherto found in the use of alizarine blue are entirely eliminated Jlne, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 457 ASTRONOMICAL. By Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S. Determination of Stellar Radial Veloci- ties with the Prismatic Camera. Maw aUciniils liavi; biiii inailt- (iLiriii^; llic la>t It-W years to utilib'e thf large light-grasping pDwer of the objective prism for determinations of stellar radial velocities. The chief difficulty is in consequence of there being no known method of introducing a comparison spectrum to give the const.ants from whicfi to measure the displacements. A melliod has recently been described by G. C. Comstock, in which he proposes to employ a specially constructed double prism, which is fi.Kcd with the refracting angles inverted so as to give two overlapping and crossed spectra. By measuring the distance apart of known spectrum lines in the two spectra produced of each of the stars whose velocities are required, and subsequently comparing these measures with the distance between simil.ar lines on a standard star, a determination of the velocit\- in the line of sight can be obtained. Asl, ni,h i/sinil -hnuiuil, Mareli, u,vIk Results of the American Echpse Expe- dition, August 30th, 1905. The expedition was divided into three parties, the mem- bers of which occupied stations at Daroca ftnd Porta Coeli, in Spain, and at Guelma, in Algeria. Prcparatkins were made for photographing the corona with long and short focus cameras, and for spectroscopic photography of the sun's chromosphere and corona. 'Ihirty-six pictures of the corona were obtained at the three stations. Several ex- cellent spectra were photographed with the four-inch para- bolic diffraction grating, ruled with 14438 lines to the inch, and h.'iving a focal length of five feet. The flash spectrum e.xtends from D3 in the yellow, to \ 3300, and shows a great number of lines. With the six-inch grating, the spectrum of the green coronal ring at X 5303 shows most interesting details, at least 15 or 20 small streamers being visible for some distance beyond the moon's limb. A special feature of this corona spectrum is the presence of a ihiil^ streamer, almost radial, and borden-d by bright streamers on either side, which was projected from the moon's limb at latitude 55" or 60", on the sun's east limb. This peculiar feature is also well shown on the 15-foot camera pictures of the corona. The Fraunhofer dark crescents, as seen visually with the spectroscope, became visible about seven minutes before the second contact, while Uj and the hydrogen lines became brightly reversed at .about one-and-a-half or two minutes before. It was particularly noticed that the green m.ig- nesium lines persisted until near niid-tot.ality. Folariscopic observations were only made at the (iuelm.i station, with very satisfactory results. Inside of 5' of arc there is practically no radially pol.irised light, showing that the luminious matter is, in all probability, solid or liquid, as is further evidenced by the continuous spectrum of this region. Between 5' and 10' of arc, the amount of polarised r.idialion increases very rapidly, indicating th.at this light is ehielly rellected sunlight. — Astrophyairot Jnuriuil, March. 1906. Parallax of the Nebulae- The distances of the nebula- are at present practically unknown, as on the whole they are exceedingly dilVicult to measure exactly, and, in consequence, direct observations of their parallax are not very consistent. In the hope that an investigation of their proper motions mighl give heller results, J. C. K.aplex n has recently onn. For convenience and accuracy of calculation, the whole term of the proper motion is not used, but only that component of it directed towards tlic aulaijcj-. The analytical method of reduction adopted assumes that the sum of the projections on some determined direction of the peculiar proper motion \anishes in the case of very numerous nebulae; of the 208 iiehuht available for the discussion, i68 were finally selected, .uul the mean deduced parallax of these is 0.0046" + 0.0012 ''. It is important to note that this value is very nearly equal to that found for the mean parallax of stars of the tenth magnitude, and as this result is from the discussion of only thirty years' observations, it is suggested that much better ileterminations might possibly result from a photographic investig.ation, which would render possible the measurement and reduction of the places of a much greater number of nebula;. Variation of Absorption Bands of Crystals in Magnetic Field. .\ll delerminalions of the circumstances causing modifica- tions of spectrum lines of substances, either as to intensity or position, become of great importance in astronomical spectroscopy when applied to the e.xamination of stellar spectra, where many peculiar features are found which have not, as yet, been produced terrestrially. Professor Becquerel has recently given an account of several re- searches, in which he subjected the absorption spectrum of various crystals to very strong magnetic fields, and he finds very interesting changes thereby introduced. The crystal showing the effect most clearly was Zenotinc (a phosphate of yttria, with erbium and rare earths). This is a uniaxial crystal, which exhibits very fine absorption Ijands, which were S])ectroscopically examined with a Row- l.md grating, a nicol prism being' introduced to separate the polarised components. The wave lengths of the lines observed were determined from a comparison spectrum of iron. The effect of the field (which was used up to 31,800 C.(j.S.) is much larger than the corresponding action on metallic vapour spectra, and is found to vary with the orientation of the crystal, and the direction and strength of the field. Important instances of dissymmetry are mentioned, which appear to be independent of the direction of the magnetic field. Another remarkable feature is the variability of sfiise in which the magnetic field displaces circular vibra- tions, whose sense is originally the same. This appears to be a selective action, which, Professor Becquerel suggests may be due to certain bands corresponding to the vibrations of positive electrons, which, if proved, will add considerably to our knowledge of the inner constitution of matter. — Comptcs Heiiihis, 13-15 (1906). New Radcliffe Catalogue of Stars for Epoch 1900. The new cil.ilogue reciMitly issued from the R.idclitTe Observatory, O.xford, contains the results of observations made with the transit circle between the years 1894 and 1903, both inclusive, under the direction of .\. A. Rambaut. Owing to various causes beyond control, the observations were interrupted several times, but this has not been al- lowed to inliuence the precision of the results, which are shown to be of a high order of accuracy. The present cata- logue gives the jjosition of every star down to the seventh magniludi." contained in the zone 85" — 90° X.P.D., with \ery few exceptions, and those only in the case of double or multiple systems. Very elaborate determinations of the pivot errors were made by a nuidification of Hamy's method, in which inter- ference fringes were produced between two plates, one of which suffered displacement when various parts of the pivot were being examined. h'ull .ui.ahtical details are given of the reductions, and minii.ii i-iMis with oilur standard catalogues. Shadow Bands at Sunrise and Sunset. .Another series of interesting observations, which appear to throw light on the curious shadow band phenomena during total .solar eclipses, have been recently described by Monsieur C. Rozet. In December, 1905, M. .\manii saw distinct bars of light and shade on the surface of ;i parti- tion, at the instant of the sun's appearance above a moun- t.iin. This led M. Ro/et to make arrangements for ob- taining a more definite determination, and he fitted up a 458 KNOWLEDGE & SCIENTIFIC NEWS. [JlINIi, 1906. white screen inside a room faciiij; the point of sunrise. The bands were easily seen, and were g^enerally straij^ht, parallel, and not at all likely to be confounded with the irrof^ular shadows produced by convection currents near the screen. .\s the result of 75 obs( rvations, he makes the following conclusions : — (a) The orientation of the dark bands, on a screen of per- pendicular rays, is constantly parallel to the part of the mountain edfje over which the sun is rising or setting. {h) The direction of their displacement is always per- pendicular to their orientation, but may be in one of two directions direct or retrograde, (c) The velocity of the motion of the bands varies con- siderably from time to time, which may have some relation to the force of the wind, as the most rapid movements occur during high winds, and the slow ones during calm weather. ((/) The bands cease to be visible two or three seconds before the sun sets, and may become visible several seconds after sunrise. If the disappearance of the sun takes place behind a vertical screen, the time of appari- tion may be lengthened to 12-15 seconds, (p) .At first the bands are wide and far apart, becoming sharper and straighter later. Their width usually was 3-4 cm., and distance apart 3-4 cm., but might vary from 1-20 cm. The width and distance apart appeared to vary with the velocity of translation. {/■) The colour of the bands was gencrallv of a uniform grey. The distances of the mountains over which the phenomena have been observed, have varied from 6-36 km., with eleva- tions of 30-22"'. In spite of these variations, the features of the bands have been fairly constant. — Comjifes Ucndus, 15, 1906. Vesuviarv Origin of Paris Fog, April 11th, 1906. In corroboration of the evidence furnished by the many striking sunsets during the latter part of .\pril, there may be considered the finding of volcanic dust in Paris just after the eruption. M. S. Meunier describes how, during the dry, yellow fog which enveloped Paris on the nth of -April last, he exposed gelatinised plates near the Ouay Voltaire, and after treating these with water, he obtained a deposit from which the soot and organic matter were removed by Thoulet's heavy liquid. There remained an extremely fine residue, the microscopic examination of which showed almost perfect identity with a sample of the dust emitted from Vesuvius in 1822. The chief differ- eiice consisted in the presence with the Paris dust, of small, perfectly spherical globules of oxide of iron. It thus ap- pears most probable that the Paris fog was produced by a fine rain of cinders which had been carried from the \'esuvian area. Photography of Corona without Eclipses. MM. .\lillochau and Stephanik propose to start a now attack on the problem of photographing the solar corona during daylight, by combining the use of the spectrohelio- graph and coloured scre'ens. As the corona is projected on a background of extremely bright sky, it is hoped that the relative intensity of the corona will be enhanced if a screen is interposed which cuts off all light except that of a green colour in the region of wavelength 5303. Then, by setting the secondary slit of their spectroheliograph on this line, the increased contrast produced may render possible the record of the coronal form. Preliminary attempts at Meudon are said to have given encouraging results, and the apparatus is to be transferred to the Observ.atory on the summit of Mont Blanc, where the absence of the lower and denser layers of the earth's atmosphere may further conduce to success. BOTANICAL. By G. Masses. Sexuality in the Mucorineae It has long been known that a sexual mode of reproduc- tion existed in the group of fungi known as the Mucor- inea;, of w'hich the moulds common on bread and various fatty matters are well-known examples. The result of sexual fertilisation consists of a structure called zygospore, which, after a period of rest, germinates, and at once gives origin to a mucor-plant. A second form of reproduction produced asexually is much more general than the sexual condition, and ajjpears under the form of myriads of minia- ture pins, with golden heads, which eventually become black. The subject of sexuality has recently been prosecuted from a new standpoint, by Blakcslee. It was observed that some .species could be readily induced to form zygospores, by sowing spores obtained from a single fruit of the asexual form. On the other hand, in many species, zygospores were never produced from s|)ores contained in a single asexual fruit, but only when a mass of spores from a zygosporic culture was used. When isolated cultures of the last- named group were grown in proximity on a suitable medium, it was observed that zygospores were formed along the line w'here the mycelium of the two colonies met. This suggested the idea that such species consisted of strains, or races, which, when grown apart, produced only a sexual fruit or sporangia, but which produce se.xual fruit, or zygo- spores, when the two physiologically different strains are grown in contact. These are designated respectiv'ely -f- and {-) strains, which is considered as non-committal as to the sexual relation of the respective strains. This condition of things is essentially similar to that present in dioecious plants and animals, although morpho- logical differentiation is not obvious in the Mucorineae. The term heterothallic is used to designate those forms that are dioecious, and homothallic is applied to the her- maphrodite species. Hybrids have been produced from (-f-) and (-•) strains of different species of the heterothallic type. The following is a part of the author's summary of this important discovery : — " The production of zygospores in the Mucorineae is con- ditioned primarily by the inherent nature of the individual species, and only .secondarily by external factors. " According to their method of zygospore formation, the Mucorinese may be divided into two main groups, which have been termed respectively homothallic and hetero- thallic. " In the homothallic group, comprising the minority of species, zygospores are developed from branches of the same thallus or mycelium, and can be obtained from the sowing of a single spore. " In the heterothallic group, comprising probably a large majoritv of the species, zygospores are developed from branches which necessarily belong to thalli or mycelia, diverse in character, and can never be obtained from the sovving of a single spore. Every heterothallic species is, therefore, an aggregate of tw-o distinct strains, through the interaction of which zygospore production is brought about. " These sexual strains in an individual species show in general a more or less differentiation in vegetative luxuri- ance, and the more or less luxuriant may be appropriately designated by the use of ( + ) and ( - ) signs respectively. " A process of imperfect hybridisation will occur between unlike strains of different heterothallic species in the same, or even in different genera. " From the foregoing, it may be concluded that the formation of zygospores is a sexual process ; that the mycelium of homothallic species is bisexual ; while the mvcelium of heterothallic species is unisexual ; and finally, that the (-f ) and ( - ) strains of the heterothallic group repre- sent the two sexes." The zvgospores require a period of rest before they are capable of germination. Marine F\ingi. H. E. Petersen has studied the microscopic fungi be- longing to the Chytridine.x', parasitic on marine algae. Twentv-five species were collected on the Danish coast, and further north, and are described in detail in Overs, k. JDansJce. rivrnsi: Schh. FnU;. New British Algae. Notwithstanding the work of centuries in investigating the flora of Britain, additional new, or previously' unre- corded, species continue to be found. Batters, in Jmirnal June, igo6.] KNOWLEDGE & SCIENTIFIC NEWS. 459 of Botany, lias some iiUcrcsiting notes on eleven new or crilical species of Britisli marine algae. Two of tlicsc were previously unl^nown, and tlirce more belonj^ to g^encra not previously recorded as British. Most of the species are minute, of the two new species, one, TJlplocohm Codii, grows between the cortical cells of another alga, Codium tomento- niim. The other new species is named Me.wqlnia neqlecta, which has probably been previously passed over as Mi'siioliiia Griff iihsiana, which it superficially much resembles, but is distinguished by the mucli shorter cortical filaments and larger spores. CHEMICAL. By C. AiNswoKTH MiTCHELi., I!. A. (Oxon.), F.I.C. The Action of Radium on Precious Stones. ExPERlMEMTs made by Herr Miethe have shown that many precious stones are changed in colour when expofcd for some time to the action of radium rays. Thus a colourless diamond from Borneo became pale yellow after eight days' exposure to the rays of an impure radium bromide, and the colour became much darker after another eight days. Heating the stone to redness reduced but did not destroy the yellow coloration. In the case of a sapphire, the light blue colour changed to green after two hours' exposure to the rays, then yellow, reddish yellow, and, finally, after 14 days, yellowish- brown. The colour disappeared on heating the sapphire, but a light yellow tint invariably re-appeared when the stone became cold. The rays did not affect the colour of the amethyst, ruby, blue topaz, or chrysoberyl ; but a tourmaline with a green end became green at any other part on which the rays were allowed to act. Philippine Wood Oils. Fluid resins closely resembling balsams in composition and characteristics are in common use as varnishes throughout the Philippine Islands, and the best known of these have recently been examined by Mr. A. M. Clover. Oil of supa is obtained from Sindora Wallichii, a tree widely distributed throughout the Islands. The oil, of which about ton litres are collected from each tree, is a mobile pale yellow liquid, which rapidly becomes dark and viscous on contact with the air, and slowly dries to a hard film when spread in a thin layer. In cer- tain districts it is also used as a lamp oil. A similar product known as balao, or oil of apitoni;, is collected by cutting cup- shaped cavities in the apitong tree. It is white when fresh, but rapidly darkens on exposure to the air, and spread in thin films forms a very tough varnish. It is superior to supa oil in its drying properties, and also differs from it in becoming solid on contact with steam. Malapaho, or oil of panoo is a colour- less product, obtained from the tree Diptcrocarpiis vernicijluus by the same method. It dries but slowly on exposure to the air, and is thus not used to the same extent as balao or snpa oil. It also differs from the former in becoming more mobile under the influence of steam. Chemicall)', all these wood oils consist almost entirely of the hydrocarbons known as sesquiterpenes. They are more or less volatile in a current of steam, and are quite distinct from the ordinary drying veget- able fixed oils, such as linseed or walnut oils, which consist of compounds of glycerin with different fatty acids. Trachinus Venom. It had long been suspected that the poison glands of the greater wcever (Triichiiius draco) contained a definite toxine, but it was not until 190; that this was shown by M. Briot to be the case. He obtained poisonous solutions possessing the characteristic properties of true toxinesby extracting the gland with glycerin containing chloroform, but did not isolate the poison in anything approaching a state of purity. The work lh,at has been done on the subject is reviewed by Dr. Oppen- hcimer in " Toxine und Antitoxine," an Knglish edition of which is now annour,ced. The toxine has a direct action upon the heart and causes convulsions and paralysis, the latter being a characteristic symptom. It is destroyed bv being heated for 30 minutes at 212' 1". and by calcium cMoride and gold chloride. In addition to its toxic function trachinus venom resembles snake venom in having a haemolytic function, i.e., the power of dissolving the red corpuscles of the blood. This lysine in the venom is destroyed when heated for about 20 minutes at 212" P.. and is thus less stable than the toxic principal. The normal serum of the horse contains an anti- hxmolysine against trachinus lysine, just as it does against the h.-emolysine of snake venoms. Trachinus venom, how- ever, is quite distinct from snake venom, for it acts in quite a different manner, and a serum rendered antitoxic to snake venom has no effect upon either the toxic or ha^molytic func- tion of trachinus venom. It is possible to produce a certain degree of immunity to the venom in rabbits by cautious in- jection of a diluted venom, and the serum of the treated animal then contains a specific antitoxine, which, however, does not invariably afford protection against the local effects of the poison. The venom of Trachinus vipera is very similar to that of T. draco, as regards its effect upon guinea pigs, but has much less action upon rabbits. Several other fish, e.g., the lamprey, appear to contain poisons which act as definite toxines, but these have not yet been investigated. The venom of the poisonous Japanese Tetrodoii iju^u) and of certain other fish, appear to contain poisonous compounds of the nature of substituted ammonias rather than true toxines, i.e., unstable specific poisons capable of producing specific antitoxines in the serum of an animal. GEOLOGICAL. By Edward A. Martin, F.G.S. The Great Californian Earthquake. The stoppage of the fires of N'esuvius has been signalised by a great earthquake which has laid San Francisco in ruins, and has resulted in a devastation such as has been unknown in any civilised territory during the present generation of mankind. \\'as there any connection between the one and the other, is a question which will at once be asked. The greatest caution must be exercised before giving an answer. If merely a coincidence, it is a remark- able one. It is certain that an enormous vacuity must have been formed in the place which fed the eruption from Vesuvius. Other material must have flowed in from regions around, and stupendous underground movements of the kind would have equivalent results. The result might be a caving-in, through lack of support, of some spot of weakness in the earth's crust, and the formation of one or more groat faults. The shock or shocks which would be given rise to w'ould travel in every direction, and when Lhey reached the surface of the earth the effect would be disastrous. Possibly secondary shocks would follow later from refraction or rellection from the earth's central core. To some such causes the present earthquake is attributable, and in this connection it is well to remember that the great Charlestown earthquake followed (ho closing of the great cralor of Kilauea, in the S;uidwich Isl.ands." Some Details of the Recent Eruption. While the receiil W.suvian outbur^t was fresh in the [Jublic mind, Professor (juiseppe de Lorenzo contributed a paper to the proceedings of the Geological Societv, which lie wrote while yet the decrescent phase of the eruption was being pursued. The maximum outburst took place during the night of April 7-8, and blew 3,000 fy R. Lydekker. Habits of the Dugong. Some interesting notes on the habits of the Indian iluf;ong, or sea-cow, are published by N. Annand.-ile, of the Indian Museum, Calcutta, in the Journal of the Asiatic Socirty nf liencjal, for last year. After stating that dugong feed largely on a green alga, as well as on a marine |ibanrrogainous plant, the author proceeds to observe that ibc mc lliod of feeding does not appear to be the same as in in.ui.ili-., which pluck the plants they eat by means of the two lobes above the upper jaw-pad, and push their food towards the mouth with the tli|>pers. .Similar lobes cer- tainlv cxi.st in the dugong, but they do not appear in fresh s]iecimens to be ca[)able of any great degree of separa- tion or movement, while the flippers are hardly long enough to give any assistance in feeding. .-Xs the upper jaw-p.id (u[)per lip) itself, on the other hand, is evidently freely niov.ible, and possibly to some extent extensile, it seems possible that it is used in plucking sea-weed, which ccrt.-iinly could be grasped between it and the lower jaw. The Jiulbor adds that, according to the fishermen, a single young one may be seeh with a female at any time of the year; but on no occasion had they observed .a female nursing its offspring with one of her flippers, while lur head and fore-part of her body were raised out of the w.iter after the fashion supjiosed to have given origin to the mermaid myth. Colour Evolution in Monkeys. A p.apcr in ihr current issue of the Zoolparently developed to accord with the pendent white lichens clothing the branches of the boughs among which these nionki ys ^lwell. Ox Warbles. .\ccording to Mr. .\. 1). I'urner, it is still unknown how the m.itigois which form the tumours known as " warbles "' on the b.icks of cattle ciTect an entrance into the bodies of iheir hosts- whether by boring through the skin, or by being sw.illowetl by the animals while in the egg-state, and subse- qucntlv eating their way through the walls of the gullet, ■ uid thus eventually reaching their final pl.ices of develop- ment. 'l"hc point is an important one to cattle-owners, as ■' warbles " are ,a source of very serious loss alike to the IhiIcIui- and to the dealer in hiiies and leather. 462 KNOWLEDGE & SCIENTIFIC NEWS. [June, 1906. Aquatic Mice. If we except the water-rat, the small mammals that have taken to an aquatic life in Europe and Asia are chiefiv shrews, of which several distinct fjeneric types are known, anions: them our own water-shrew. In .South .America, on «he other hand, accordinij to the researches of Mr. O. Thomas, of the IJritish Nluseum, it is mice that have adapted themselves to this mode of life. .Some years nffo that i^entleman described one of these water-mice, which feeds on small fishes, under the appropriate name of lelifliyninijs ; its home beintf the mountain-streams of Peru. Recently, he described a second, distinpjuished by the absenie of ears, under the equally apposite title of Aiuiliimys. Now, he has had the p;ood fortune to be able to n.inie a third as Hhmmi/x, nearly allied to the second, but dislintjuished by the retention of ears and its plossy fur. I'rcirii both the others, the first-n;uned s^enus differ b\- Hie peculiar structure of its incisor teeth. Papers Read. ,\t Ihe meeting of the Zooloifical Society, on .Xjiril 10 (the only one held durinj^ the month), Mr.' C. T. Ret,'.-in communicated a paper on Trinidad fishes ; Messrs. Thonison .and Henderson described alcyonarian zoophytes from Zanzibar; Dr. J. F. Geinmill di.scussed the phenomenon of "cyclopia" in trout-embryos and other fishes; wliile Mr. P. I. Lathy described certain butterflies. REVIEWS OF BOOKS. BOTANY. Allen Flora of Britain, by S. T. Dunn, B.A. (West, New- man, ;uid Co. ; 5s. net.) — Most British botanists will probat)ly be somewhat astonished to learn that the author considers 924 species, or practically half the number of British plants, as aliens, or in other words plants that have been introduced either directly or indirectlv through human agency. The crucial test adopted is as follows : If a plant is found growinj^ in perfectly wild and natural surroundings it is deemed indigenous, whereas if a plant only occurs in cultivated areas it is considered as an alien. This test dubs as indigenous all plants growing in elevated regions, or in localities that have for some reason not been disturbed by man, whereas broadly speaking, plants that grow in culti- vated land, hedge-rows, &c., are introduced, or aliens. Now as the great bulk of land, say, below 500 feet elevation, has within the last thousand years been under cultivation at some time or other, and much of it almost continuallv so, it is dilTicult to conceive lowland plants as occupying other than cultivated areas if they succeeded in surviving at all. Many widely distributed plants now thoroughly naturalized, are undoubtedly aliens, having been introduced accidentally along with grain, wool, ballast, &c., and .some of these have been with us for centuries ; but before such a wholesale statement as to numbers can be accepted, stronger and more convincing evidence than is contained in the work under consideration will be required. Apart from the leading question, the book contains much useful information re- specting the habitats and gcogniphical range of the plants dealt with. CHEMISTRY. Treatise on the Effects of Borax and Boric Acid on the Human System, by Dr. Oscar Liebreich (tr.anslaled from the German. London: J. and A. Churchill ; pp. vii. -f 70. 5s. ncl). --.\n interesting series of experiments on living subjects was recently concluded by Dr. Wiley, of the U..S. Department of .Agriculture, who arrived at the con- clusion that borax and boric acid were undoubtedly in- jurious when used as preservatives in food. In this pam- phlet, which is well illustrated with diagrams. Dr. Liebreich subjects Dr. Wiley's results to a critical examination, and cojnes to the opposite conclusion. He considers that any injurious symptoms observed were due to unsuitable hygienic conditions and to the choice of unsuitable persons for the experiments, and not to the effect of the borax. The pamphlet will be read with interest bv those who are in- terested in Ihe subject, but it shows the necessity of much more work being done before a definite conclusion can be formed. It may be mentioned that the Parliamentary Com- mittee on Preservatives, in this country, came to the same conclusion of " not proven," as Dr. Liebreich, notwithstand- ing some strong medical evidence in the other direction, and recommended that a small proportion of boric acid should be jjermitted in butter, cream, and hams. The question, however, is still unsettled, and no tradesman who ventures to use l)oric acid cm consider himself safe from prosecution. In fact, .so chaotic is the law that quite recently a shop- keeper, sunniioned for selling preserved food in one borough, called the Medical Officer of Health from .an ad- joining county as a witness for the defence, and won his case. This prmiphlet of Dr. Liebreich is also likely to ap- pear frequently as a witness for the defence in' similar cases, which will continue until such time as we have the malic]- proprrlv Ihrashrd out and Ihe use of preserv;itives eilli. r Irg.-ilised or m.ade illegal. ETHNOLOQY. Mexican and Central American Antiquities, Calendar Systems, and History. Twenty-four papers. By E. Seler, E. I"(ii st( niann, P. .Schellh.as, C. Sapper, and E. P. Dieseldorff, .Sniillisonian Institution, Bureau of .American Ethnology. Bulletin 28, Washington, 1904. The late Director of the Bureau of .American Ethnology was very well advised when he determined to publish translations of a number of foreign [jnpers on the archeology and glyphic writing of the semi- civilised peoples of middle .America. These have now been |)ublished under the supervision of Charles P. Bowditch, and lliey afford to the ethnologist a mine of information on subjects to which otherwise he could obtain access only with the greatest difficulty. One has only to glance at this well illustrated book to see that it is of interest not merely to the .Americanist or archaeologist, but also to the general ethnologist. The latter, however, will have to search for his material, as most of it is .scattered all over the volume, and pick out what he requires from papers of diverse kinds, but in some cases, as in the articles on the priesthood, ceremonials, deities, and religious conceptions of the Zapotees, he will find it pretty fair sailing. In a new subject, such as this, and dealing with interpretations based on glyphs which have no " Rosetta Stone " to guide them, authorities are apt to differ from each other, and to modify their own previously expressed opinions, thus the reader must be continually on the watch for these pitfalls. M.atliematicians and those who like number puzzles will find full scope for their ingenuity in the consideration of the Ma\a Calendar. .According to a widespread tradition, the Toltec nation was the originator of all arts and sciences, and among other things the invention of the calendar is ascribed to them, and we are told that they carried their books with them on their migrations. The calendar is the alpha and omega of the Central .American sacerdotal wisdom, and the great mass of Mexican and Maya manuscripts is nothing more than an elaboration of this calendric system in respect of its numerical theory, its chronology, and its system of divination. The nature of this calendar, consisting^ in the fact that it originated from the fundamental number 20 in combination with the number 13, is well known. A simple calculation shows us that the peculiar period of 52 years in use among the Mexican races proceeds directly from the application of this fundamental system to a .solar year of 36-5 days. There is still a diversity of opinion as to how far the iSIexicans themselves were able to harmonise this system with actual time, the solar )'ear, and the revolu- tion of the various heavenly bodies. .Among the Maya races the system seems to have been brought to perfection on the numeric-theoretic side in particular. It seems cer- tain that not only the movement of the sun, but also the movements of the large planets were noted, and that these people were capable of connecting the period of revolulion of these bodies with the solar year of 3^15 days, and with the period ot 20 x 13 days, the true basis of the .system. The apparent period of revolution of Venus may be set down with tolerable accuracy as 584 days. Five such re- volutions give us the figures of 2,920, or eight solar years of 365 days. This precise number is plainly the basis of (he computations on certain pages of the Dresden manu- scri])l. But 65 such periods give us the number of 37,960, June, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 463 that is, double the period of 52 years, which is the direct result of the application of the dcsin^nation of days in accord- ance with the system of the 20 charnctcrs and the 13 digits to the solar year of 36:^ days. In like manner the revolu- tion of Mercury around the ?im, which is completed in 115 days, .'eems to be broug^ht into connection with the period of 20 by 13 days ; for 104 of these revolutions produce the number 11,960, which is also forty-six times the period of 20 by 13 days ; and this number clearly forms the basis of other [lages in the Dresden manuscript. .Unfortunately, it is almost hopeless to look for an exact chronoloj;;y in the native manuscripis or moniunents, but several acute scholars are working' hard at these difiicult glyphs, and the publica- tion of this book will enable others to follow iheir labours willi Ljrcater ease. Halda Texts and Myths, Skldegate Dialect. Recorded by John K. .Swanton. Ibid. Bulletin 29, Washington, 1905. A very cor;siderable number of folk-talcs have already been collected in North America, but Prof. W. H. Holmes, the chief of the Bureau of .American Ethnology, in succession to the late .\i,ajor Powell, rightlv considers that the whole of it should be collected and published, as they form a very im- portant clement in the ethnological study of a people, especi- ally when, as in this case, the tales are given as literally as possible. Many of the talcs are printed also in the vernacu- lar, and thus they have a |)hilological value in addition to the insight they give into the religious ideas of the people. One is impressed by these tales bv the tremendous hold spiritual power has over the imagination of these as of most Glher North .American peojiles, for success in life is attributed to it in the same manner that the Mel.anesians regard all good fortune as the result of Mana, a term which an .American would translate as " medicine." Incident.-illy these tal(!s throw light upon (he socird and daily life of ihe natives. QEOLOQY. The Founders of Geology, by .Sir .Archibald Geikie, F.R.S. (M.icniillan and Co., |i]). 4X6, los. net). — \Vc are glad to see this work in a second edition, covering as it does ground which to many is as a sealed book. Geology becomes the more interesting when one studies the work of pioneers of the science, and the obstacles which they had to overcome. Opportunity has been taken to considerably extend the scope of the edition of 1807, and to give a sketch of the progress of geological ideas from the times of Ancient Greece onwards. Naturally, the greater part of the book is taken up with the lives of leaders of Ihe 19th century, in the halcyon days of the science, whilst in the period ap- proximating t.T the present day the men famous in geologi- cal discovery arc so numerous that the narrative has of necessity to be confined to the mention of but a few. Per- haps contemporary geologists will form Ihe subject of another volume, and among Ihe first to lie menlioned in such a connection will be llial of the aiilhor. F.. A. M. METEOROLOCiY. Meteorology in Mysore for 1904, being Ihe results of ob- servations at Bang.nlore, Mysore, Hassan, and C'hitaldrug. Twelfth .Annual Report.- This publication, by John Cook, M..A., F.R..S.E., &c., director of meteorology in Mysore, is worthy of the " Model .State," containing as it does in addition to the ordinary features associaletl with an annual meteorological volume, a complete and comparative summary for the whole 12 years of the eslablislinient, which is also a model in itself, the four stations, at the corners of a not quite regular quadrilaleral, having been founded successively in a little more than a year (B.ang.alore observ.a- tions commencing .\i)ril r, iSijj, and Mysore, M.av 10, i.^ij.O, and being provided with similar st.-iffs and equipment, so th.al the work is rc.ailily comparable, l^or Government |Hir- po^^es the formula adofjied to give daily mean temperature is apparently considered insulTicient, a second formula called the Government of India mean being also employed for olllcial purposes. India, however, is loo l.arge a district for an cmiiirical formula lo be of universal application, and it is obviously not quite right for Mysore. It would seem better to determine Ihe daily variation for every district separatelv, if not for every observatory, as is doiic for some I?ritish ■■tations, for instance, and use that instead of the Govern- ment formula. Some inlcresling features from our insular point of view may be noted in connection with the actual results. The extreme range of the barometer for the year is only about half-an-inch, but as all the stations are high (2,400 ft. to 3,100 ft.), and tropical, this is more a matter for satisfaction than surprise. The maximum temperature for the year was 940.0 at Hassan, 970.3 at Bangalore, 99°. 9 at .Mysore, and 1000.3 at Chitaldrug, all on different dates. The minimum readings being respectively 460.5, 510. 9, 530.2, and 550.3, also on different dates, and only two in the same month. It is fairly dry, the humidity at each station running down to nearly 10. The actual figures are 9, 10, 12, 13. There is not much wind, the greatest daily movement being 462 miles at Mysore, that at Hassan never exceeding 175 miles; the total rainfall at the wettest station, Bangalore, being 31! inches, and at the driest, Chitaldrug, 23 inches; Hassan, however, heading the list of wet days with 11 1 and of daily fall with 3, inches. There are instructive plates giving curves of d.iily mean barometer, dry bulb, wet bulb, maximum and minimum temperature, rainfall cloud, wind velocity, and direction for each of the four stations, and also six-day .and monthlv mean curves for several elements com- pared with those for Madras. We may congratulate the model slate on having secured a model director, and the director on the opiiorlunity of continuing a work which will grow in value with excry vear, in a climate which for many reasons seems eminently fitted for meteorological investiga- tions. SCHOLASTIC. niementary Electrical Calciilalions. W. II. N. James and n. I.. S^inds (Longmans and Co., 3s. 6d. net). — This consists in details of calcul.ations sucli as an electrical engineer requires lo m.ake. It is the outcome of a number of lectures on such calculations and is intended as supple- mentary to nuich class work. The calculations are of an elementary nature, and for this reason there are none in connection with alternating currents, self-inductance, and capaeitv, Ihe properties of which can be adequately studied only by a senior student. We think, however, that in this elemenlary bonk it would have been very advantageous lo deal with some electrostatic |)roblems without which a studi'nl will never thoroughly understand the part played bv Cfiudensers in .altern.aling work. The treatment here is accurate ; but it must be understood th.it Ihe lliorv underlying Ihe calculations is not given; for this the reader mu I have recourse to other text-bocks or to class leaching. The solution in many cases is obtained by me.-ms of curves ; these certainly prove of great aid in ( nabling one lo understand the variation of any quantity. First Stage Physiography (Section I.), by R. Wallace Stew ut, I)..Sc. " The Organised Science .Series." (L'ni- versity Tutorial Press, Ltd., pp. 256, 2S.) — This section deals with mechanics, physics, .and chemistry, with experiments, questions, and answers to each part. It is a useful aneing fixed as in the above models, is borne upon the upright triangular bar of the fine adjustment, for it is by this limb that the average student persists in lifting his microscope. A new upright stand for rough laboratory use has been added, which is fitted with a coarse adjustment only, corresponding to similar stands made by Leitz and other makers. Perhaps of even more interest, however, to the general microscopist is the fact that in the present catalogue Messrs. Zeiss have considerably reduced the prices of many of their achromatic objectives, the old D of ^-inch focal length, for instance, being reduced from ^2 2s. to ^,"1 15s., and the i-i2th inch oil immersion from ^"8 to jQ6 5s. The Huygenian oculars, nose-pieces, &c., show corre- sponding reductions. The apo-chromatic objectives and compensating oculars, unfortunately, are not re- duced in price, and amongst the former we note that the one inch of .3 N..\., formerly supplied for the lo-inch tube, no longer appears, .'\part from its own interest, the catalogue contains much valuable information on optical matters, set forth in a lucid and instructive manner, but I regret to see that Messrs. Zeiss continue (on page 19) to give inaccurate magnifications for the compensating oculars a.s used for the Continental length of tulx', and to state that when these are used for the lo-inch tube " to obtain correct ocular matjni- fication (the italics are my own) it is necessary to multiply the figures engraved on the oculars by 1.5." Of course, the ocular magnification does not vary at all under such circumstances, and it is the objective magni- fication that needs to be multiplied by 1.5, the total magnification of (X-ular plus objective gi\ ing the same result whichever method of working be adopted. The practical disadvantages of the former system are that it leads to much confusion of thought — as only those who, like myself, have frequently to answer questions on the subject fully realise — that it is incorrect, and, therefore, unscientific, and that it causes a worker to underrate by 50 per cent, the power of the ocular which lit; is using and the consequent strain which he is putting upon his objective. I hope that in the next edition of the catalogue this small, but not unimportant, matter will receive attention. Microscopical Material. .Mr. W. S. Rogers, of .Slough, is good enough to send me lor distribution some shore scrapings from Adelaide, -South .'\ustraJia. The quantity is, unfor- tunately, limited, but I shall be glad to send some to the first applicants who send me a stamped and ad- dressed envelope, and a very small box, to prevent crushing of the shells. Applications must be accom- panied by the coupon to be found in the advertisement pages of this issue, and as I can only supply the first- comers in rotation until the material is exhausted it will be seen that early application is necessary. I shall, however, keep a small quantity for foreign readers. I am always grateful for any microscopical material for distribution, and hope that any of my readers who can assist me in this way will do so. Notes and Queries. Diatomaaviis Deposit. — Mr. T. W. Robertson, Glasgow, who is much interested in diatoms, would be grateful if any reader could assist him to get some diatomaceous deposit from the province of Simbrisk, Russia, and from Seudai, Japan. Mr. Robertson would be glad to defray any expense, or to know of anyone Ukely to supply his wants. Volcanic Dust from Mont Pclce Eruption.— The Rev. W. Hamilton Gordon, Farebam, Hants., would be glad if any reader could give him any information as to the requisite treatment for volcanic dust, and as to what points of interest there are iu such dust. Mounting Diatoms in Realgar. — Replying to \V. H. B., Lei- cester, Mr. Basil F. T. Tryon kindly sends me the following, echoed from an article by Mr. J. W. Gifford in the "Illustrated Annual of Microscopy" for 189S: "Realgar is prepared by heating together equal parts of clear red realgar and stick brimstone (flour sulphur is apt to be full of dust). In order to prepare the mount a drop of the solution containing the diatoms must be dried on a very thin cover-glass by passing it, diatoms uppermost, through the flame of a spirit lamp. .\ small piece of the medium is then placed on the glass slide, which is carefully warmed in the same way by passing to and fro through the flame until the medium melts, and while both are still in the tlame of the lamp, the cover is turned over and carefully lowered until contact is made with the medium. .As soon as it has spread out to the edges a chp must be put on, or the medium will crack off in cooUng, which must take place very gradually. The best thing is to put the mount, still hot, into a small tin bo.\, previously warmed, and place the whole in a vessel of boiling water and put aside to cool. The water must, of course, not touch the mount. There will be many failures ; but when a good mount is made it will be well worth the pains taken. This medium is very yellow, but this is no objection." Mr. Tryon adds, •• I have been told that the making of realgar mounts is very dangerous, on account of the arsenic fumes given off iu heating. They should be pre- pared in the open air and in fine weather. Damp ruins them. King with Hollis' glue." CM.. Tunbriiigc Wells.- -I am informed that the fungi in the slide you have sent nie are Triposporium elegans, one of the Deniatiex. They have apparently not been yet worked out and are consequently put amongst the p-ungi Imperfecti, whose life history is not known. [Commiiniciitioiis and Eiii/uints on Mieroscopie,!! matters should be addressed to F. Shillinglon Scales, •'Jersey," St. Barnabas Road, Cambridge.] 466 KNOWLEDGE & SCIENTIFIC NEWS. [June, 1906. The Face of the Sky for June. By W. Shackleton, I'.K.A.S. This Sun. — On the ist the Sun rises at 3.51 and sets at 8.4 ; on the 30th he rises at 3.4S and .sets at 8.1 8. Summer commences on the 22nd, when the Sun enters the sign of Cancer at 9 a.m. ; this is the longest day, the Sun being 16^ 34" above the horizon. The equation of time is negligible on the 1 5th, hence this is a convenient day for adjusting sundials, as only the correction for longitude is needed. Sunspots and prominences appear to be slightly on the wane, but at this period of solar activity the disc is rarely devoid of spots. The position of the Sun's axis, equator, and helio- graphic longitude of the centre of the disc is shown in the following table : — Axis inclined Centre of disc Heliographic Date. S.orN. of Sun's Longitude of from N. point. Equator. Centre of Disc. May 31 16=" 12' W 0° 37' s 96" 58' June 5 14° 18' W 0° i' S 30° 48' 12° 18' w 0" 35' N 324- 38' .. 15 10° 12' W 1° 12' N 258° 28' ,, 20 8° I' W 1° 47' N 192° 15' ..25 5° 48' W 2° 21' N 126° 5' ,.30 .. 3- 32' w 2° 55' N 59'^ 54' The Moon :— Date. Phases. H M. June 6 .. ., 13 •• ,, 21 .. ,. 29 •• 0 Full Moon d Last Quarter • New Moon J First Quarter 9 7 11 2 12 p.m. 34 P-m 6 p.m. 19 p.m. „ 6 .. „ 18 .. Perigee Apogee 5 10 12 a.m. 12 p.m. OccuLTATioxs. — The following occultations are visible at Greenwich before midnight : — Disappearance. Reappearance. Date. Star's Name. 1 1 Mean S Time. Anele from N. point. 1 Mean Angle from Ti-"^- point. June 5 V 7 49 Librae . . . . li Sagittarii p.m. 5'6 7-57 4-0 10.45 125= ll&° pm. 9.0 275=" 11.51 259^ The Planets. — Mercury (June i, R.A. 3'' 56™; Dec. N. 19° 57'. June 30, R.A. 8'' 8"" ; Dec. N. 2i°'53') is in superior conjunction with the sun on the 8th, and hence the planet is unobservable. Towards the end of the month the planet is an evening star in Gemini, and may be observed immediately after sunset low down in the N.W. ; on the 25th the plant sets at 9.40 p m. or jh 20™ after the Sun. Venus (June i, K.A. 6^ 31m; Dec. N. 24" 44'; June 30, R.A. 81j 59™; Dec. N. 19° 2') is an evening star in Gemini, setting about 2 hours after the Sun throughout the month. The planet is pretty bright and should be looked for shortly after sunset, itwill be found in that portion of the sky illuminated by the afterglow of the setting Sun. The apparent diameter of the disc is i2"-5 and it appeals gibbous, 0^84 being illuminated. On the evening of the 24th the planet will appear in pro.ximity to the crescent Moon, Venus being 2|° to the north. Mars (June i, K.A. 5'' 30™; Dec. N. 24° 3'. June 30, R.A. 6'' 5411 ; Dec. N. 23" 49') is practically unobservable as he sets very shortly after the Sun. Jupiter (June I, R..\. 5'' 2'" ; Dec. N. 22 ' 23' ; June 30, R.A. 5'' 31"! ; Dec. N. 22° 56') is in conjunction with the Sun on the loth, hence the planet is unobservable. Saturn (June i, R.A. 23'' 6™ ; Dec. S. 7° 44'. June 30, R.A. 23'' 8™ ; Dec. S. 7° 39') is a morning star, rising about midnight near the middle of the month. The planet is at the stationary point on the 27th, after which date he continues to describe a retrograde path in Aquarius for the next four months. Uranus (June 15, R.A. iS*" 31™ ; Dec. S. 23" 35') rises about 9 p.m. near the middle of the month, and is on the meridian about i a.m. The planet is in opposition on the 29th, but he is not well placed for observation as he is situated low down in Sagittarius. Neptune (June 15, R.A. 6^ 41"^; Dec. N. 22° 14') is out of range for observation, as early next month he is in conjunction with the Sun. Meteor Showers: — Radiant. Name. Date. R.A. Dec. Characteristics. June — July. . June 13 .. h. m. 16 48 20 40 -21° 4-61° a Scorpiids a Cepheids Fireballs. Streaks, swift. Telescopic Objects: — Double Stars, &c. — Scorpii, XVI.i' o™, 5.19^33', mags. 2-7, 5'2; separation i3"'i. f Lyra>, X\TII.h4i™, N. 39° 33', known as the " double- double " star, can just be separated by the naked eye, but with a pair of opera glasses it is readily divided into two components fj and e^, mags. 4-4 and 4'8. Usinga3-in. telescope and a power of about 120, each of these stars can again be divided into pairs, 3"'2 and 2"-6 apart re- spectively, each component being about magnitude 5*5. M 57 (Lyra), the " ring " nebula. This nebula is the only annular nebula accessible to telescopes of about 3-in. aperture, and even then requires good seeing. It is easily found, being situated about s of the distance from fi toy Lyrae. The usual appearance in a 3-in. telescope is that of a rather large nebulous star, but it bears magni- fication well, and its annular character can easily be made out with a moderately high power. M 80 (Scorpio). A compact globular cluster half way between " and ,i Scorpii ; looks like a nebula in small telescopes. Temperature of the Hemispheres. The Southern Hemisphere as a whole is colder than the Northern Hemisphere, and a new determination of the mean temperatures has been made by M. Julius Hann in the Lehrhucli dir Metcorologie. In Southern latitudes the annual temperature varies froms^deg. C. in Lat. 5odeg. to 2odeg. below freezing in Lat. Sodeg. The mean annual temperature of the Southern Hemisphere is 13-6 deg. C, and ranges from 17-3 deg. in January to 10-3 deg. in July. In the Northern Hemisphere the mean annual temperature is 15 2 deg. C, and ranges from 8 deg. C. in January to 22-5 deg. C. in July. In the higher latitudes the diflerences of temperature seem to be accentuated in the direction of a general lower temperature for the South. The mean annual diflerence of temperature between the two Hemispheres is about 1-5 deg. C. 467 KDooiledge & Seientlfie flems A MONTHLY JOURNAL OF SCIENCE. Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. Vol. III. No. 20. [new series.] JULY, 1906. SIXPENCE NET. CONTENTSSee page V. Holes in the Heavens. By J. E. Gore, F.R.A.S. There are many dark spots in the Milky Way which seem to be openings or holes in that wonderful zone of stars. These dark spots or "coal sacks," as they are also called, seem to have been first noticed by Pinzon, in 1499. They were also described by Lacaille in 1763. The most remarkable of these spots is the well- known "Coal Sack " near the Southern Cross. It is of roughly oval or "pear-shaped " form, about eight degrees in length by five degrees in width, and forms a conspicuous object in the sky of the southern hemi- sphere. It is completely surrounded by the nebulous light of the Milky Way, which is here of considerable brilliancy. The bright stars a and ji Crucis — the brightest stars of the Southern Cross — nearly touch its south- eastern edge. It contains only one lucid star within its boundaries. With reference to its northern border, Sir John Herschel says : " The transition from rich Milky Way to almost complete darkness is here very sudden." It is, however, by no means devoid of faint stars. On a photograph taken in 1891 by Mr. H. C. Russell, at the Sydney Observatory, numerous very small stars are visible, but there are several spots which seem to be completely void of stars, and absolutely black. One of these remarkable holes is near /3 Crucis, and another near a Crucis. There are other remarkable " coal sacks " in the Milky Way. A long, narrow, dark spot runs from a Centauri, for several degrees towards the north-east. There are several in Scorpio, one of larger size be- tween ij and f Cygni, and one south of a Cygni. Examined with a telescope, the Milky Way shows many examples of small coal sacks; and some mav be seen with even a good jjinocular field glass. One night when Sir William Her.schcl was examining a part of the Milky Way closely east of the globular cluster 80 Messier, which lies between i' and a- Scorpii, he suddenly exclaimed to his sister — the famous Caroline Herschel — " Hier ist wahrhaftig ein Loch im Himmcl " (Here, truly is a hole in the Heavens). It was an ab- solutely black vacuity, about four degrees in width, perfectly frtx; from any stars, and especiallv remarkalile owing to its proximity to one of the richest globular clusters in the heavens. Closelv south of Herschel's dark "hole" just mentioned, Professor Barnard has photographed a great nebulous region surrounding the stars p Ophiuchi and 22 Scorpii.* This photograph shows several dark lanes in what seems to be at least a comparatively thin sheet of stars, and this distin- guished astronomer thinks "it is certain that these stars are at the same distance as the nebula, for they form part of it." With reference to the Milky \\'ay in general, he thinks that the stars comprising it are " comparatively very small bodies, and that thev con- sequently differ vastly in point of size, at least, from the ordinary stars of the sky." If this be so, and the evidence seems to point in this direction, it would follow that their distance from the earth is not so great as their faintness would lead us to imagine. In his Cape Observations, Sir John Herschel gives a list of 49 spots in the southern hemisphere " totally devoid of any perceptible star." But probably photography will reveal the presence of some faint stars in these dark spots. Closely east of the star e Ophiuchi is a "dark chasm," which passes south and west of that star, and there are several other dark " lanes " and holes clearly visible on the photograph taken by Professor Barnard at the Lick Observatory. Another small black spot was observed by Barnard a little north-west of the star ■> Sagittarii. This seems to have been previously seen by Trouvelot, who says : " C'est comme un sac a charbon en miniature, ou une ouverture de la Voie lactee a travers laquelle la V'ue penetre au dela de oc grand assemblage d'etoilcs." .\ little south-east of a Cephii, a photograph by Barnard shows a ring of nebulous light, with a com- paratively dark interior, at least the stratum of stars filling the rings seems pierced by several holes. The "key-hole" openings in the great nebula sur- rounding the variable star ?; .-\rgus is a remarkable feature of that wonderful nebula. A little south of this hole there is a " kidney bean " shaped opening, shown in Sir John Herschel's drawing in the Cape Observa- tions. This opening is visible on a photograph taken by Sir David Gill in March, 1892. The photograph confirms the accuracy of Herschel's drawing, and shows that the opening is in all probability a real hole through the surrounding nebulous matter. In the region round the star 12 Monocerotis there is a remarkable nebula of irregular shape, somewhat resembling in its general character the great nebula in the " sword " of Orion. Dr. Roberts, describing a photograph he took of this nebula, says : " Some re- markable tortuous rifts meander through the nebulosity on the north preceding half of the nebula; their margins • The rings round the briehter stars io the photograph are due to a photographic eft'ect, and do not exist in the sky 468 KNOWLEDGE & SCIENTIFIC NEWS. (July, igo6. are sharp and well defined in the midst of dense nebulosity. They are as clearly cut as we see the canyons of great rivers, but the-r width may in reality be millions of miles, for we have no reason to assume that the nebula is nearer to the earth than the stars. It is, indeed, possible that the stars which dot the sur- face are nearer to us than the nebula." About 3 degrees north-east of the star t* Canis Majoris is another nebula of irregular shape. Dr. defined, and suggestive of the idea that in consequence of some internal strain, operating from opposite direc- tions, the nebula was rent asunder, and the parts separ- ated from each other." In another nebula in Monoceros, photographed by Dr. Roberts, a little west of the triple star 15 Monocerotis, there is a remarkable vacuity or hole. Dr. Roberts calls it a dark tortuous rift, and says : " The rifts prove that the nebulje are not globular, but are like clouds Great Nebula near p Ophiuchi. {From a ;.r< with w Inq'. rlused One of the most attractive cxhiljits was that of .Mr. I'". Enock, who, by means of natural colour lantern slides, showed and dcscriljed the adaptability of lepidop- terous insects to the changeful circumstances of their environment — Nature's own way of protecting insect life. The illustrations which we gi\e fail to convey an ade- quate idea of the manifold colours thrown \'pon the amongst the flowers of the umbelliferous plant, Fools' Parsley. When " working " the flower, the insect's wings are wide open, but let a cloud or shadow pass over, and they im-nediately close together as depicted in our photograph (near cross), the protective green colora- tion and irregular moltlings effectually masking the living liutterflv and rendering it almost indistinguishable from 472 KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. its floral surrounding-s. The rolled-up leaf, adjacent to the birch leaf in the fourth illustration of this series, is the chosen home of a beetle. Its twig-like companion is none other than the larva of a Thorn Moth (S. illumaria). The advantages of the three-colour process of photo- graphv were also apparent in Mr. W. Saville-Kent's brightly illuminated transparencies illustrating the fauna of the Polynesian coral reefs, especially those re- ferring to the gaily coloured fishes which make the recesses of such coral growths their habitation. A striking series of specimens of fossil plants from the English coal measures, with illustrative microscopical slides, was on view, a display with which Miss M. Ben- son, Miss W. Brenchley, Prof. F. Oliver, F.R.S., and others were identified. A newly discovered petrified stem from Shore, Lancashire, indicated the structure to be of a type hitherto unknown. Some models of branching stems, w-hich furnished accurate reconstruc- tions of petrifications, \\ere, too, of great interest. Sir William Crookes conducted an elaborate series of experiments in illustration of some properties of the diamond. The squeezing of a natural crystal into steel by means of hydraulic pressure in order to demonstrate the hardness of diamond was beautifully shown by the optical projection upon a screen of the slow transit of the object into the metal until it became lost to sight. In the electric arc the precious gem was seen burning up and turning into graphite. The facile manner in which it will plane a glass surface was shown by a slide of curh' glass shavings. One diamond thrown upon the screen had been obtained from the remarkable Canyon Diablo meteorite, of Arizona. Prof. W. Gow- land also showed under the microscope diamonds found in this meteorite. Some will, perhaps, remember that it was this particular meteoric mass that secured the ubiquitous attentions of American speculators a year or so ago, when the inevitable company was formed, with the idea — of course a futile one, of exploiting it for diamonds. From the Royal Institution laboratory came Sir James Dewar's new charcoal calorimeter and thermo- scope. In this instrument charcoal when utilised at the temperature of liquid hydrogen and in conjunction with certain gases exhibits great sensibility to heat and light radiation, and can be used in calorimetry. There were also spectrum tubes containing helium, neon, krypton, and xenon, these gases having been separated by the charcoal method. A demonstration of the scientific uses of liquid air formed a popular feature. The fine piece of photo-micrographic apparatus for ultra- violet light, designed by Dr. Kohler, and ably ex- plained by Mr. ^lax Poser, of the firm of Zeiss, was considered by physicists present to be a splendid instru- mental achievement. It was suitably shown for the first time in this country at the soiree. In archaeology. Dr. Flinders Petrie contributed ex- amples of black incised pottery from Egypt, of date 2000 B.C., as well as photographs from Sinai taken during the progress of his recent exploring ex- pedition in that quarter. Lastly, we should not omit to mention a set of diagrams sent by Prof. Karl Pearson, F.R.S., and Mr. J. Blakeman, illustrative of Lord Ravleigh's solu- tion of the "problem of the Random Walk," a mathematical excursion, decidedly perplexing, how- ever, to the layman. For information on the subject, our readers should refer to Nature, Vol. 72. Some Rudimentary Structures. By R. LVDEKKER. On a first visit to an English assize court, the stranger, if he occupy a sufficiently elevated position, will scarcely fail to notice the presence of a small black patch on the top of the full-bottomed wig of the pre- siding judge, and, if he be of an inquiring disposition, he will want to know the reason for this apparently useless feature. Reference to any treatise on the his- tory of costume will inform him that this apparently unmeaning patch is the last remnant or survival of the coif, or black cap, with pendent lappets, originally worn by the " sergeants learned in the law," from among which bod}- the judges were formerly selected. The patch affords therefore an excellent example of a structure which, although now perfectly useless, once had a definite and more or less important function. In other words, it exactly corresponds to what are com- monly called rudimentary structures in the animal kingdom. I say commonly called rudimentary struc- tures, purposely, because in scientific circles they are now more generally designated vestigiary structures; and, strictly speaking, quite rightly so, for a rudiment properly means the commencement of any thing, whereas these are the last vestiges of the structures they represent. They are decadent, and not incipient. Nevertheless, since the term vestigiary is somewhat cumbrous, and by no means so well known as rudi- mentary, I shall take leave to use the latter, especially as it is employed by Darwin, in this sense, in the " Origin of Species." Rudimentary, or more or less completely functionless organs are extremely common in both the animal and the vegetable kingdoms; and they can have but one meaning. That is to say, they afford practically de- cisive and irrefutable evidence in the minds of all unprejudiced persons of the truth of the doctrine of evolution. For it is absolutely inconcei\ able that such useless structures, which in many instances can be traced by regular gradations into those whi-h were evidently functional, could have been created in their present condition. Indeed, if we had no other evi- dence in favour of the evolution cf animal forms from pre-existing types, it is perhaps not too much to say that the evidence of these rudimentary structures would alone be sufficient to prove the truth of that great doctrine. .Since rudimentary structures are so common in nature we suffer from an embarras du richesses in at- tempting to select instances to form the subject of an article of the length favoured by the Editor of this journal; and the reader must consequently be not sur- prised if he finds no mention of many cases of this kind with which he may be more or less familiar. As a matter of fact, cases of this nature to which the present writer has had occasion to devote special attention form the chief of those noticed in this article. Among the larger animals of the present dav, no species is more highly specialised than the horse (and its immediate relatives), and it would consequently be only reasonable to expect that in the course of its evolutionary progress this creature should have found certain elements in its organisation superfluous, and should therefore have done its best to discard them. This expectation is fully realised by the actual state of July, igo6.] KNOWLEDGE & SCIENTIFIC NEWS 473 the case; and it may be regarded as a fortunate cir- cumstance that the total elimination of such super- fluous structures appears to be an exceedingly difficult process, so that their rudiments, or vestiges, are fre- quently left to tell the tale of their gradual degeneration. As regards some of the rudimentary organs occurring in the horse, one of the most interesting is the rem- nant in the skull of the Eastern breeds, of the cavity in front of the eye, which, in the extinct three-toed hip- parions probably contained a gland similar to the larmier, or face-gland, of deer and many antelopes. Fuller reference to this rudimentary gland-cavity, which is often very faintly marked, will be found in " Know- ledge & Scientific News " for August, 1904. At first sight there may seem to be little, if any, connection between this last vestige of the hipparion's face-gland, and those curious warty structures on the inner side of the limbs of the horse, which are com- monly known as callosities, or chestnuts (Fig. i). It appears to be a very genera! belief that these structures Fig. I. -The Left Fore the Callo tid Hind Limhs of a Horse, to ties, or "Chestnuts." are for the purpose of serving as cushions, or pads, to ease the pressure on the limbs when the animal is lying down. This, however, is obviously out of the question; and it is quite certain that the callosities are now use- less remnants of structures that were once functional. The question is, what those structures were. One theory is that they were foot-pads, or cushions, com- parable to those on the foot of a dog or a cat; and in order to support this hypothesis, it has been stated that they arc situated much lower down in the foetus than in the adult, so as to be situated on what corresponds to the foot of other mammals. This, however, is not the case, as is demonstrated by specimens exhibited in the Natural History Museum. A much more probable theory is that these callosities represent scent-glands, comparable tO' those on the limbs of deer. Strong support to this is afforded by the fact (as I am informed) that the secretion which exudes from these callosities when cut will cause a horse to follow any substance anointed therewith; and also by the poacher's practice of carrying a fragment of one of them to keep his dog quiet. Tliat a rudi- | mentary foot-pad would have any effect of this kind is, of course, quite out of the question, although nothing is more likely than that such emanations should pro- ceed from a decadent foot-gland. In regard to the connection between the rudimentary face-gland of certain horses, and the callosities, it may be noted that both face-glands and foot-glands appear to be for the purpose of aiding animals in finding the whereabouts of their fellows; the leg or foot glap'"'~ leaving a scent on the grass or jungle through which they pass. If, however, animals live on open plains, as is the case with horses and zebras, where they can see one another at long distances, such aids may be quite unnecessar)'. We know that the horse and its kindred have lost the facial scent-glands of their ancestors, and what is more likely than that they should at the same time have discarded their leg-glands, of which the callosities are the last remnants? That the horse does retain vestiges of the foot-pads of its ancestors, who applied a portion of the sole of their foot, instead of only the nail (hoof) of the middle toe, tO' the ground, appears, however, to be undoubted. At the hinder basal extremity of the second joint of the pastern is a curious little horny spur (very con- spicuous in the foetus), known to veterinarians as the ergot; and this ergot seems to represent the central pad of the foot of the tapir. .As this part of the foot of the horse does not touch the ground, the pad is of no functional importance, and has consequently degen- erated to this curious little horny spur. Other rudimentary organs in the horse are the splint- bones lying on either side of the upper end of the fore and hind cannon-bones, and representing the functional metacarpal and metatarsal bones, and sometimes even the lateral toes of the hipparion. In domesticated horses not only are these bones useless, but they are actuallv harmful, producing the disease called splint. How this accords with the theory that the horse has been specially evolved for the use of man, may be left to those who hold that theory to explain. Even this does not exhaust the list of rudimentary structures in the horse. In the " knee," or carpus, of the hipparion exists a bone kncmn as the trapezium, which supports one of the aforesaid metacarpal bones of the lateral toes. In the horse this bone is functionless and very minute, and is present only in about fifty out of every hundred individuals; so that it is evidently about to follow in the wake of the lost lateral toes. In the hor.sc only certain elements of the limbs have become rudimentary, in order to permit the greater development of other elements of this part of the skeleton. In some groups of animals on the other hand, one or both pairs of limbs are, in many instances at any rate, completely wanting; and had it not been that they arc occasionally represented by minute vestiges, we should have had no direct evidence that they ever existed in the group. As it is, wc are absolutely certain (if evolution be the true explanatior of the resemblanceof animals to one anotheri that snakes and whales are descended from creatures with four limbs. In regard to snakes, most members of the group, show no' traces of limbs, either externally or internally; but in the family groups which include the boa-con- strictors and pythons (the Boid^ of naturalists) it fortunately happens that in manv species, at any rate, minute vestiges of the hind-limbs are retained, as if for the very purpose of telling us the story of their ancestry, for it is quite certain that in most instances .It all events, these ludiments are absolutely useless. 474 KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. The second illustration to this article shows the ex- ternal vestiges of the hind-limbs in an African python {python sebce) over twenty feet in length. These vestiges take the form of a pair of horny spurs, or claws, about three-quarters of an inch in length, and situated on the under surface of the body at the com- mencement of the tail. In the specimen figured, the skin has been slit along the middle lire of the belly, so that the two claws are separated from one another by the width of the skin of the back and flanks, whereas in nature they would be comparatively close together. Each claw in this specimen was supported on a bony core, corresponding to the terminal bone of one of the toes of a lizard's foot, while eml>edded in the flesh beneath was a much stouter bone, probably represent- ing the femur, or thigh-bone, and also a minute nodule, which may be the last remnant of the pelvis. It must not, however, be suppo.sed that all pythons exhibit these vestiges as distinctly as in this specimen. On the contrary, in the skin of a Malay python [P. molurus) of five-and-twenty feet in length, which I recently ex- Fig. 2.— Part of the Skin of the Tail of a Python, showing the Horny Spurs representing the Hind Limbs. amined, the external rudiments of the limbs were minute lobes, scarcely larger than the head of a big pin. Somewhat similar vestiges of the hind-limbs are retained in the small burrowing tropical snakes of the family Typhlopidce, as well as in the members of a nearly allied group; but in no snakes have any traces cf the front-limbs been detected. Tliese vestiges, then, afford decisive evidence that snakes are descended from reptiles with functional hind-li.iibs, from which it may also be inferred that their early ancestors were four-limbed; the front limbs, as in the case of certain snake-like lizards, being the first to disappear. The further inference that those snakes which retain rudimentary hind-limbs are the most archaic members of their kind, has been recently con- firmed by the discovery that pythons and boa-constric- tors display certain primitive features in other parts of their anatomy. Space admits of but very brief allusion to the case (if whales. .As everyone knows, all the members of the order Cetacea, inclusive of whales, dolphins, por- poises, &c., have but a single pair of limbs, the front pnes, which are modified into paddles for swimming. It is, however, far less well known that deep down among the muscles of the body of the Greenland right- whale and its immediate relatives are embedded cer- tain small and useless bones which represent those of the pelvis, and part of the hind-limbs of less specialised mammals. These rudimentary bones are alone sufficient to demonstrate the descent of whales and dolphins from four-limbed ancestors; and when taken in connection with the fact that cetaceans are air-breathing (as op- posed to gill-breathing) creatures, lead to the conclu- sion that their ultimate ancestors were terrestrial. Curiously enough, it is the most specialised whales (that is to say, the true, or whale-bone whales) that alone retain rudiments of the hind-limb itself; these vestiges in the toothed whales, such as the sperm- whale and dolphins, being restricted to the bones of the pelvis. In this respect, then, cetaceans are unlike snakes, in which, as we have seen, it is the most primi- tive forms that alone retain vestiges of limbs. Turning to the subject of the third illustration, we have an exceedingly interesting example of a more or less completely rudimentary structure, in the so-called worm-like appendage, or appendix vermiformis, of the human blind gut, or ccecum. In this connection it may be well to mention incidentally that the disease to which this organ is so frequently subject, derives its name of appendicitis from the organ itself, and its al- Fig. 3. The Vermiforn ternative title of typhlitis, from the Greek 7-i'0X:s, blind, in reference to the blind gut of which the appendix forms the termination. In a great number of mammals, both herbivorous and carnivorous, there exists at the angle formed by the junction of the small intestine or ileum with the large intestine or colon, a large blind pouch or diverticulum, which probably aids in the digestion of food bv pre- venting its toO' rapid discharge. The ca»cum, as it is called, is remarkably w^ell developed in the horse and the dog, in the latter of which it is coiled in a spiral manner. In the human subject, on the other hand, the Cfficum proper is very short, but is prolonged by the aforesaid vermiform appendage, which is usually from four to five inches in length, with a calibre of cnly about one-third of an inch. This appendage corre- sponds to the coiled caecum of the dog, of which it is obviously an aborted rudiment. .As many of us know by sad experience, it is only too likely to become choked by closely packed, partially digested, or undigested food; and the opinion has been very generally held that it is an altogether superfluous and u.seless organ whose complete elimination would be an immixed ad- vantage to the human race. For instance, on page 282, of " The -Student's Darwin," by Dr. .\veling, we find the following statement in reference to the ver- miform appendage : — July, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 475 " It is to man useless. Nay, it is worse than useless. It is at times a special death-dealer. Small, hard bodies, as the seeds of fruits, entering the appendix, cause inflammation and death. In the animals lower than man, this organ is of great size and functional importance. That of the orang-utan is long and con- voluted." On the other hand, an eminent surgeon has recently expressed the opinion that the appendix may still have a certain amount of digestive function. To controvert such an opinion would obviously be presumption on my part; but whether or no it still retains any active func- tion, the structure in question is evidently a pronounced example of a rudimentary organ, and one which, by the way, leads to the conclusion that man is descended from an animal furnished with a long and complex cacum. Incidentally, it may be mentioned that, in addition to man, the only animal possessing a vermiform appendix is the Australian wombat, a member of the marsupial order. Truly a remarkable instance of parallelism in retrograde development ! With Figure 4, I come to the last section of my subject, and I must confess that I am by no means cer- tain that it properly belongs to my subject at all. The object represented on the left side of the photo- graph in question is the tip of the tail of a lion, show- ing the presence of a small horny prickle or spur (s) buried among the terminal tuft of hair. In the natural condition, it should be mentioned, the spur was com- pletely concealed by the long hair, and it was only by cutting away a portion of the latter that it was made visible. What may be the history or use (if it has a use) of this spur, no one seems to know, and I have no intention of hazarding a guess. The old story, that it was for the purpose of enabling the lion to goad itself into a fury when about to attack, is obviously an ab- surdity, more especially as it seems that the spur is Fig. 4-Tip o( Tail of Lion (on (he left), and ..i N.i,l i.iiled W allaliy (on tllc riRht', sliowing Horny Spur and .Nail. develop<'d in onlv a comparatively sm.all percentage ol lions. If any of my readers can sohe this problem, they will be the means of removing one blank from future zoological text-books. I fear it will not help them much to learn that one species of kangaroo, or rather wallaby, pos.sesses a very similar caudal appen- dage, which is, however, of a somewhat more nail-like foim, as shown at A^ on the right side of Figure 4. It may be added that all the figures in this article have been reproduced from photographs of specimens exhibited in the Natural History Rranch of the British Museum at .South Kensington. The Petrified Forest of Arizona. The petrified forest of Arizona is seldom visited be- cause of its inaccessibility to the ordinary traveller, though it is but 2,500 miles from New York. It lies in a district possessing archaeologic attractions as well as geologic problems, for the village of Adamana, in Apache country, which is the only human habitation within easy reach of the forest, is the centre of a neigh- bourhood full of Indian ruins. The most interesting of these ruins are those of the cliff dwellers who made their homes in the minor bluffs which border the canyons and plateau-like spaces of the petrified forest. The extreme height of these cliffs does not exceed a hundred and fifty feet, but they are identified with the forgotten Indian tribes of the Hopi and Zuni; and an ancient fort together with various rock inscriptions and other relics and ruins give colour to the legend that the Agtees once inhabited this region. The only dwellers now in this great intersected plateau 5,000 feet above sea-level are the historic Navajo Indians. Such are the situations and the surroundings of the petrified forest of Arizona, which is divided into three sections marked by the same general characteristics. Frag- ments of lava, beds of basalt, and the peculiar pitch of the upheaved strata point to a period of volcanic activity. The first casual opinion that is formed in surveying the petrified tree trunks is that an ancient forest flourished on the spot; that it may have become submerged and petrified under the saline action of some encroaching inland sea, and that centuries after the great winds and sandstorms of the high plateau swept off the covering of sand and silt from the tree trunks. This theory, plausible as it may at first sight appear, must, however, give place to the alternative theory that almost the whole of the vast and remark- able deposit dropped from a neighbouring plateau, where it was for long embedded, and whence it was eventually washed into the valley seven hundred feet below. Quite apart from the scientific interest of the .\damana forest is its wonderful picturesqueness and beautv. Each step reveals deposits of topaz, agate, cornelian, amethyst, onyx, and chalcedony in such an advanced stage of mineralisation as almost to give them place among gems and precious stones. Chips and segments of gem-like chalcedony, which once were por- tions of living trees, cover the earth beneath one's feet, and vari-coloured columns (hard as flint and shaded like the rainbow) are huddled around, still bearing the familiar outline of their original forest state. The colours at the sections where the trunks have broken across are always the brightest, and fully suggest the radiant development that can be secured by the lapidary. In the conglomerate stratum of the plateau are still embedded thousands of tree trunks, some projecting and showing round the bark an encrustation of sand- stone, exactly similar to that found on the surface of the trees in the petrified sections at the lower level. Firs and oaks were the main constituents of the once living forest, vet minute search among- the deposit, whi(-h covers an area of more than eight square miles, has failed to reveal any vestige of acorn or cone. This circumstance, together with the fact that no branches have been found, that none of the trees are upstanding, and that several of the short stumps have the root end 476 KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. Petrified Tree trunks near Adamana. Natural bridge formed by a Petrified Tree trunk in the Ariiona Forest. July, 1906] KNOWLEDGE & SCIENTIFIC NEWS. 477 uppermost, is accepted as strong evidence tliat the forest did not grow on its present site. There is the further argument that the number of trunks found huddled together all over the area are greatly in excess of the number of trees that could have grown to a vigorous maturity on such a limited surface. That the action of silicificatiqn set in after the destruction of the forest is a matter of universal acceptance; yet a very interesting theory could be developed on this point from the existence round the base of the trees of a thick sandstone coating which lessens on, or entirely disap- pears from, the bark encasing the topmost sections. In the third and largest section of the forest, thirteen miles from Adamana, there are several liundred whole trunks partly embedded in the earth, some of which exceed one hundred and fifty feet in length. The colours here are very striking, and the crystal deposits of considerable frequency. The second or middle forest is the smallest of the three, but in its two thousand acres are many fine specimens of wood agate, those named the Twin Sisters being the most widely known. The distance between Adamana and the first forest is only six miles, and on the road between there are prehistoric ruins made out of logs of this fossil wood, wliich also served for the construction of implements found in Pueblos hundreds of miles away in the desert. The majority of the trees in all parts of the dead forest are broken off in sections, ranging from two to twenty feet, but the first forest, which has a higher altitude, possesses one of the most remarkable exceptions, which imquestionably grew on the spot where it now lies. It measures one hundred and eleven feet in length, with a base diameter of four feet four inches, graduating to eighteen inches at the other end, and in its prostrate position it spans a fifty feet wide canyon, making a unique natural bridge over the intermittent river, whose bed is twenty feet from the canyon's edge. ^^^^^^ An Interesting New Asteroid. On February 22, if)i)(), a new astemid was detected by Max Wolf at Heidelberg, which was found to have a re- niark.ibly siniill rate of retrogradation, about 30 sees, daily. The provisional designation of this body is TO. Later Dr. Herbcrich deduced circular elements for the asteroid, which indicated that its mean distance was S-OS- almost identical with that of Jupiter, and from more recent observations, April 22, combined with those of February 22 and March 23, has computed elliptic elements. These show a mean distance a little greater than Jupiter, and aphelion distance al)()iit one unit beyond the orbit of Jupiter. A. C. D. Cninmielin dr.aws attention to (he fact that Ibe family of asteroids now extends from distance i.i (perihelion of Eros) to distance 6 (aphelion of TG), and in consequence the in- vestigation of the perturbations of T(i by Jupiter should prove very interesting on account of the equality of their mean motions. In the present positions of the orbits no very close approach occurs. — (Observatory, June, 1906.) "The value of glass may far exceed that of gold," says Amateur Wurk (Boston). " A contemporary draws atten- tion to its enormously increased value when made up into microscope objectives. The front lens of a micro-objective, costing 5 dollars, does not weigh more than about 0.00 iS gram, which weight of gold is worth about one cent, and so (he value of a kilogram of such lenses would be about J,ooo.ooo dollars. The cost of the raw material for making this weight of glass is from 5 cents, and thus, when wvirUrd up into the shape of a lens, the glass has been iiii iia^cd in value aliout fifty million times. Such disparitv brlwi'cn the cost of the raw material and the manufactured article is probably a record in industrial technics." Photography. Pure and Applied. By Chapman Jones, F.I.C, F.C.S., >.\:c. T/ie Efficioicy of Shui/crs. — Although shutters are now very commonly employed, there are many false ideas held with regard to them. It has been stated so frequently that it seems to be commonly accepted as a fact, that focal-plane shutters gi\e an efficiency of one hundred per cent. Before making any precise statements, it is necessary to make clear what is meant by the word cfjiciency. If it is defined as the ratio between the actual period of the exposure and the time that would be necessary to produce the same light effect if the shutter were removed, that is, if the open- ing and closing took no time at all, then the focal-plane shutter is the least efficient of any pattern, for the time taken for tlie narrow slit to pass across the front of the plate is always considerable, because of the great distance it has to travel. But if efficiency is taken as applying, not to the whole plate, but to each point of it separately, so giving the focal-plane shutter all possible advantage, still its efficiency is not, and never can be, one hundred per cent. Considering shutters of ail classes so far as I know them, the general state- ment, that in giving their minimum exposures the efficiency tends towards fifty per cent, may be accepted as correct. That is, the actual period is about twice as long as would give the same light effect if the uncovering and r€-covering of the plate or lens t(X)k no timeatall. Theapplicationof this pruicipleto the focal- plane shutter is not generally appreciated. By reason of the exigencies of construction the slotted blind must bean appreciable distance in front of the sensitive surface, and the aperture of the lens must be considerable. It therefore follows that each edge of the opening gives a penumbra, and that the exposure of e\ery point of the plate begins gradually, increases to a maximum, and then diminishes to zero, as in all other shutters. There are some shutters that give an efficiency of less than fifty per cent., but this is because either of faulty con- struction or the endeavour to get an exposure that is shorter than tlie apparatus will properly give. The advantage of the focal-plane shutter is not in its greater efficiency when giving its minimum exposure, but that its shortest exposure (having regard to only one point of the plate) is, say, about a tenth of the shortest ex- posure given by a lens-shutter, so that in giving the same exposure with both of, say, the one-hundredth of a second, the lens-shutter is working at its quickest and with its minimum efficiency, while the focal-plane shutter is giving ten times its shortest exposure with a corresponding gain in efficiency. On the other hand, a diaphragm shutter that opens from the centre will permit of the use of a larger opening in the lens for the same defining power and depth of definition, be- cause the greater part of the exposure is given \\\\\\ smaller apertures than the full, by reason of the shutter acting the part of an expanding and contracting diaphragm. There are many other details that might be referred to in this connection, for the matter is much more complex than it is generally considered to be. What is the Onc-hundrcdth of a Second?. — It is eas>- to talk glibly of such an exposure as this, and to engrave the fraction on the shutter, but the definition of it is not so simple. Of course, such a period of time ? 478 KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. "^ simple enough in itself, but, as applied to photographic exposures, it may mean three distinct things, and which of the three it means I have never been informed when buying a shutter. It may signify (i) the whole dura- tion of the exposure; (2) the efi'ective duration of the exposure; or (3) the equivalent exposure. With all slnitter.s, the exposure begins and ends gradually, and the "effective duration" neglects the time taken up at ihe beginning and end of the exposure when the light action is so small as to be negligible. The " equivalent exposure " is the duration of an exposure that would give the same light-action if the opening and closing re- quired no time at all. If the photographer has a satis- factory amount of exposure with an aperture of //16, and one twenty-fifth of a second, and he wants to shorten the duration of the exposure and still maintain the same amount of light-action by increasing the aperture of //8 and the shutter speed to one-hundredth of a second, then he wants equivalent exposures marked on his shutter, and this, I believe, is what most people do want. But if he calculates from the rate of a mov- ing object and the permissible blur, the maximum duration of exposure that will conform to his condition^, then he wants to know the effective duration of the exposures. I believe that such calculations are very rarely made in practical work, even in those cases where they would be simple and advantageous. The whole duration of the exposure is of use only in a secondary sense, or under very exceptional experi- mental conditions. A A'cii/ SliutUr. — It is risky tO' call anything new. But I believe the adjective is strictly applicable to a shutter that will shortly be put on the market by Messrs. Taylor, Taylor and Hobson. It embodies several new details, the consideration of which will be found in a communication made bv Mr. William Taylor to the Royal Photographic Society, and published eighteen months ago in their Journal. The shutter is diaphrag- matic, and acts the part of a diaphragm as well as a shutter by means of a simple contrivance that limits the movement of the leaves, so that the maximum open- ing is the aperture desired. .\ separate iris diaphragm being unnecessary, the space that has to be left between the lens components for the working of the shutter is practically the same as is required for the usual diaphragm alone. The shutter has four leaves, arranged like an iris diaphragm, but the edge of each is so cut that the opening made is always eight-sided, a much nearer approach to a circle than is often obtained in such apparatus. The opening and closing is done always at the same rate, the varying periods of ex- posure being obtained by stopping the movement for the desired time when the opening is at its maximum, and not by slowing the moving parts, so that the longer the exposure the greater the efficiency. For the most usual exposures, the twenty-fifth of a second and longer, the efficiency is, I believe, from over 90 to about 97 per cent., and the difference between such figures and a hundred is negligible in general work. The shorter ex- posures are arranged to give the due proportion of light effect; they are definitely made to be the equivalent ex- posures, as explained above. The example I have gives exposures from one second to the one-hundredth of a second. The pneumatic break is exceedingly compact and efficient, and all the mechanism is enclosed so that it is protected as far as possible from dust. I have referred rather in detail to this particular apparatus because it seems to me a distinct advance in shutter mechanism, and, indeed, to leave very little, if anything, to be desired as a shutter for general use. ASTR.ONOMICAL. By Charles P. Bitlek, A.K.C.Sc. (Lond.), F.R.P.S. Constant Deviation Prisms for Radial Velocity Determinations. .An interesting property of tlie constant deviation prism was demonstrated recently by T. H. Blakesley, showing that by employing two prisms of the same angle, but inverted with respect to their bases, there would be produced two spectra of opposite sense. When a star was brought into the field the two spectra would, of course, have their colours ia opposite directions, and the adjustment would be such as to make any particular line coincident in the two spectra if the light source were at rest; for a body in motion the line would be split up into two moving in opposite direc- tions in the field of view. Measurements of the distance apart of these lines will give the necessary data for calcu- lating the radial velocity of the star. Work at Greenwich Observatory. May. 1905-May, 1906. In his report presented to the Board of \ isitors on May 30 the .\stronomer-Royal briefly summarises the various classes of investigation which have occupied the staff during the past year. Transit Instrument. — This has been repaired, and owing to some difficulty connected with the repolishing, the instru- ment was out of use for about two months. During the rest of the year 6,335 transits were observed, and 5,531 ob- servations with the circle. Two hundred and fifty-seven re- flection observations of stars were made, and numerous determinations of level and collimation error. The transits are completely reduced to 1905, December 31, and apparent K..\. is formed to igo6, May 6. The circle observations are completely reduced to 1905, December 31, and as far as apparent X.P.D. to 1906, May 6. The new working cata- logue of stars of magnitude 9.0, and brighter, between the limits of+-24<' 10+32° of N. Declination, forming reference stars for the Oxford .Astrographic Zone, has been completed, and includes more than 12,000 stars, the places of which have been brought up to igio. A new determination of the pivot errors was made in November, showing them to be insensible. Altazimuth. — Various adjustments have been made of the object-glass mounting, and the instrument mainly used as a reversible transit. Observations of the sun, moon, planets, and fundamental stars have been made throughout the year. 28-Inch Befractor. — This has been used for micrometric measures of double stars, diameters of Jupiter and its satellites. Thompson Equatorial. — With the SO-inch refltctor photo- graphs of Jupiter's satellites \T. and VII., minor planets, Nova -Aquilae, Comet a (1905), and various nebula; were obtained during the year. With the 26-inch refractor 72 photographs of Neptune and its satellite were taken on 28 nights, and are now being measured. Spectroscope. — A number of experimental spectra of sun- spots have been photographed in the 3rd order spectrum. Astrographic Equatorial. — One hundred and si.xty-four photographs have been taken on 60 nights. Various re- measures of the catalogue plates have been made in the zones 80° to the Pole. A table is given showing the num- bers of separate stars measured for zones of 5" in the section allotted to Greenwich, from which it appears that consider- ably more than six times the number of stars will be in- cluded in the resulting catalogue than are contained in the Bonn Durchnuisterunr}. Reproductions of enlarged prints of the chart plates have been made as far as possible. July, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 479 Photoheliograph. — Photographs of the sun were obtained on 210 days. The Thompson telescope was taken to Sfax for the total solar eclipse, and excellent photographs of the solar surroundings obtained. By the co-operation of other observatories photographs were obtained for measurement of spots on facute on 364 days during 1905, the missing day being 1905, January i. Maqndic Observations. — The principal results for 1905 are as follows : — Mean Declination = 16° g'-g West. T-, • , T, (40173 (British Units.) Mean Horizontal Force = J^„ ;,. . ., .. , 1 1-8523 (Metric Units.) Mean Dip (with 3-in. needles) = 66^' 55''55". In 1905 there were no days of great magnetic disturbance, and only 12 of lesser disturbance. Personal. — During the year Mr. F. VV. Dyson, the chief assistant, was appointed Astronomer-Royal for Scotland, and the vacancy was filled by the appointment of Mr. A. S. Eddington, B.A. In concluding his report the Astronomer makes some strong remarks concerning the serious interference with the work of the observatory which is caused by the new power station of the London County Council, situated on the river- side, due north of the transit circle, and only about half a mile distant. The tremors caused by the engines are stated to be much more violent than would have been anticipated from experience of the engineering plants that have been carefully tested. Stereoscopic Determination of Stellar Proper Motions. Herr Dr. Max Wolf, Director of the Astrophysical Ob- servatory at Heidelberg, has for some years past very successfully employed the stereoscope for detecting asteroids on photographic star charts taken at intervals, and he has recently extended this delicate method of comparison to the determination of proper motions of stars perpendicular to the line of sight. The process involves the operation of com- paring, in an ordinary stereoscope, two photographs of the same portion of the sky taken at several years' interval. In the case of plates of a well-known star submitted to the Paris Academy there is a distinctly visible alteration in the appearance of the star from its surroundings, although the two component photographs were obtained at an interval of only four years. Another comparison refers to a star of the ninth magnitude in Leo, whose proper motion now be- comes known for the first time. The two plates for show- ing this were taken at an interval of fourteen years. Not only is the detection of proper motion rendered much more easy by this method, but Dr. Wolf is of opinion that its magnitude can be determined more accurately than by the usual micromctric method. As examples of other problems to which the stereoscopic method of comparison may with advantage be applied, men- lion is made of the examination of meteors, comets, the lunar mountains, and certain nebulae (Comptes Bendus, 142, pp. 1007-8, May, 7, 1906. Parallax of Nova Persei. M. O. Bergstrand has recently ende.ivoured to determine the parallax of the Nova I'ersei from observations made at the observatory of Upsala in 1901 and 1902. His result is p - o"oj ± 0"'0I Distribution of Radium in the Earth's Crust. An important paper dealing with the results of an in- vestigation of the mode of occurrence of r.-idium in the earth's crust has been communicated to the Royal Society by the Hon. R. J. Strutt. He concludes that : (i) Radium can easily be detected in all igneous rocks. Granites, as a rule, contain most radium ; basic rocks the least. (2) This distribution of radium is sufficiently uniform to enable a fair estimate to be made of the total quantity in each mile of depth of the crust. (3) The result indicates that the crust cannot be much more than 45 miles deep, for otherwise the outflow of heat would be greater than that actually ob- served. The interior must consist of totally different material. This result agrees with Professor Milne's con- clusion drawn from a study of the velocity of propagation of earthquake shocks through the interior. (4) The moon probably consists for the most part of rock, and, if so, its internal temperature must be far greater than that of the earth. This explains the great development of volcanoes on the moon. (5) Iron meteorites contain little, if any, radium. Stony ones contain about as much as the terrestrial rocks which they resemble. — (Proc. Roy. Soc, 77A, pp. 472-485, 1906.) New Method for the Discovery of Asteroids. .-Vn interesting method has recently been adopted by J. H. .Metcalf for the photographic determination of asteroids. It may, perhaps, be best described as the inverse procedure to that adopted by Max Wolf at Heidelberg, where the star field is accurately followed by clockwork, and any asteroids present record themselves as short trails among the numer- ous minute points representing the stars. When the asteroids are in opposition they retrograde about 34" an hour, and thus in an instrument of large dimensions the trails must of necessity be somewhat faint ; therefore a limit is soon reached to the brightness of asteroids which will be detected by the trail. The author, therefore, calcu- lates the mean velocity of the asteroids in the region it is proposed to examine. By inspection of the positions and daily motions given in the Berliner -Jahrbuch, it is possible to get a close value of the extreme values for the motions of the asteroids already known in a certain region. The general direction of motion will be parallel to the elliptic. By means of a finding telescope with micrometer wire the camera is so adjusted that it can be moved at short intervals in the calculated direction ; at the end of the exposure all the stars in the field wdll be represented by short trails, while any asteroids which may be present will most probably be shown as points or onh' very short lines. Excellent photo- graphic reproductions of asteroids found in this way are given, one of about the thirteenth magnitude. The author acknowledges the description of a somewhat similar method of photographing unknown objects which was published by E. E. Barnard in 1897. Testing of Optical Surfaces. M. G. Meslin describes a \ery interesting method of test- ing optical surfaces which is more widely applicable than the now well-known method of using Newton's rings and monochromatic light. By employing a grating instead of the parallel test plate a new series of interference phenomena are brought into play, and the most important factor from a practical standpoint is that these new bands are very distinct in ordinary white light, so that little special apparatus is needed. The grating is placed over the surface to be tested, either in contact or a few millimetres distant. .An interesting distinction of these grating interference bands from Newton's rings is that they are scarcely coloured, being almost achromatic when viewed at an inci- dence about 45" ; further, the diameters of the rings diminish when the incidence is increased, whereas Newton's rings increase in diameter under similar conditions. They may be rendered very brilliant by increasing the reflecting power of the surface to be tested, say, by silvering, and hence the method may be applied to the examination of metallic sur- f.ices, and also of liquids, such as mercury. — Comptes Kendus, 14J, pp. 1,039-1,042, May 7, 1906.) BOTANICAL. I^y Ci. M.^ssEK. Protective Adaptations in Plants. Some remarkable instances of protective adaptation have been described, and beautifully illustrated, by Sir William Thiselton-Dyer, in the Annals of Botany. The plants under consideration are natives of South .Africa, and, growing in an arid region, had two problems to face — to reduce to a minimum the loss of water by transpiration, which was accomplished by assuming a spheroidal form, thus present- ing a minimum of surface ; and, secondly, to secure as far as possible against the danger of such succulent masses 48o KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. b(-ing- eaten by animals; tlii» wius eflccted by simulating in appearance the pebbles aniong>t which they grow. Mciembryanthcminn triiiualinii grows amongst rolled, waler-worn pebbles, which it so closely resembles in form, colour, and mottling of the surface, that it is very dilVicult to distinguish between the two. Mesembryanflinmum bolusii is even more difficult to detect in its natural surroundings. The mimicry is with angular rock-fragments instead of water-worn pebbles. The plant consists practically of two fleshy leaves of a dull grey -green colour, and the resemblance is enhanced by minute pustular spots, witli which the surface of the leaves is studded. 1 he general effect produced is that of a lichen {Lecanoraj growmg on weathered stones. This plant is rendered con- spicuous for a short period by its bright yellow llowers. In a third plant, A nacampseros payyt-acca, also a native of. the Karru, the leaves are minute, and are concealed by their large, dry, membranous stipules. The general ap- pearance of the plant is compared to the dejecta of some bird, the branches becoming whitened towards the tips. In tliis instance, the llowers are very minute, and concealed under the stipules. New Rubber Producing Plants. In a f'arlianK-nt.ir) Iveporl of a l^otanical Mission through the forest districts of Buddu and the Western and Nile Provinces of the Uganda Protectorate, Mr. M. T. IJawe announces the discovery of a considerable number of forest trees, many of which are of considerable economic importance. One of the most important results of the mission was the discovery that the Lagos silk rubber tree, Fantumia elastica, was a native of Uganda. During previous years considerable expense had been incurred in mlroduciiig this tree for the purpose of forming experi- mental plantations. This lack of information in the present instance has a compensating advantage, as, had its presence been known to the natives, it would probably soon have been ( xterminated, judging from the reckless manner in which they collect rubber from other trees. Two more trees, present in abundance in various dis- tricts, Landolphia dawei, and Clitandra orientalis, will, in the near future, form important sources of Uganda rubber. Numerous Icinds of forest trees, many of gigantic propor- tions, were observed during the journey, a good percentage of which proved to be new to science. As examples : — Bahamocitrus, the type of a new genus, has large globose fruits, and the seeds are embedded in a very fragrant balsam. Caiiarium Schwciiifurthii is a large tree with an edible fruit containing a quantity of fragrant balsam, used as a substitute for incense in some Catholic churches. rviicedanum fraxiiiifolium, a large, umbelliferous shrub, forms a favourite food of elephants. Jiakiiutes wihoniana, another tree hitherto unknown, has a large fruit, enclosing a seed full of oil. Elephants are very fond of the fruit, and are mainly responsible for its distribution throughout the forest. Finally, a large toad-stool, common in some districts, furnished with a tapering stem two to three feet long, which penetrates the soft humus of the forest, is used as an article of food by the natives. This also proved to be undescribed, and has been named Collyhia matrorhiza. Arctic Flora. Mr. H. G. Simmons lias contributed an interesting ac- count of the higher plants inhabiting the polar region, in Fidenskabs-Sehkahet of Kristiania. EUesmereland, the northernmost great island of the Arctic-.\merican Archi- pelago, was the portion investigated, and up to the present has furnished 115 species, belonging to 24 families. The genera containing the largest number of species are Carcx and Saxifraga (11 each); liaimncuhts (6); Draba and Foa (S) ; Pedicularis, Potcidilla, and Olyceria (4 each). Of these, only two genera, Androsacc and Chrysosjylcnium, and the toUowing species, Alsinc llussii, Carcx mcmhiaiwpacta, Taraxacum pumilum, and Fua evaijans, are absent from Greenland. Of the EUesmereland flora, 72 species are cir- t unipolar plants, spread all over the Arctic region, and also to some extent, outside. Ill tropical and temperate regions, it is well known that altitude is a factor of primary imi)ortance in determining the distribution of plants. In Arctic regions, this fact does not hold good. The author states that height is of very little consequence, perhaps none at all in these regions. -At an elevation of a thousand feet the same species, under favourable conditions, were cjuite as large and vigorous as when growing at the sea level. Ths two important factors arc water supply during the period of growth, and exposure. Southern slopes, with the requisite amount of water, always furnished the greatest variety and abundance of vegetation. CHEMICAL. By C. AiNswoRTH Mitciii:ll, 1;..\. tO.xon.), F.I.C. The Effect of Blows on Chemical Elements. It was noticed by Herr Doermer that when metallic calcium was hammered on an anvil there was frequently a fairly violent explosion, accompanied by a Hash of light and sparks, and it was found that the explosibility was promoted by the presence of rust on the anvil, or by traces of iron oxide as impurities in the metal. Professor Cohen suggested that the explosion might be due to the calcium having absorbed gases, just, as is well known, platinum can do, and experiments showed that calcium was able to occlude a considerable amount of hydrogen. The more extensive observations independently made by Dr. Ohmann, and recently published in the Benchte of the German Chemi- cal Society, suggest that in some cases, at all events, the explosion of calcium is due to a vaporisation of the metal near the edge, where the pressure is greatest, and a com- bination of the vapour with the atmospheric oxygen. If the calcium be hammered in o.xygen the Hash produced is much more brilliant, while if the metal be struck with a rounded hammer only a faint light is observed, for then there is less vaporisation at the edges. When several slight blows are given in succession there is an accumulation of heat, and eventually a gentle blow may then cause an ex- plosion. Similar phenomena occur in the case of other metals. Sodium hammered on an anvil gives out a bright flash, and small yellow flames are sometimes produced. Potassium gives marked effects with almost every stroke of the hammer, small violet flames with clouds of strong- smelling vapours being formed, while small incandescent fragments may be split off by sharp blows. Lithium also gives brilliant Hashes, frequently accompanied by a report and by sparks. The light emitted is much more intense than in the case of potassium. Powdered aluminium and magnesium only give small sparks, and do not explode. Of the non-metallic elements tried by Dr. Ohmann only phos- phorus gave a positive result. It was expected that the blow would cause the phosphorus to ignite, but instead of this it was flattened out into a dough-like mass and emitted sparks. Liquid Nitrogen. Dr. H. Erdmann has recently investigated the properties of liquid nitrogen more fully than had previously been done. It is a clear, mobile, colourless liquid which differs greatly from liquid air in its physical properties. It produces a much greater lowering of temperature on evaporation, and is thus a good cooling agent. When it is poured over a bulb of oxygen the gas condenses in bluish drops on the inside of the glass. Liquid nitrogen is a good solvent for liquids that boil at a low temperature. It mixes readily with liquid ozone. As a chemical agent it is as indifferent as gaseous nitrogen, and burning magnesium wire plunged into it is immediately extinguished. V\"hen poured over metallic calcium, however, it enters into combination to form calcium nitride, which yields ammonia on treatment with water. The Dangers of Tinned Meat. The exposure of disgusting practices in connection with tinned meat has naturally frightened many a consumer, although under proper supervision this method of preserving July, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. flesh should be quite free from objection. It is, therefore, of special interest at the present time to see what risks are run in eating such meat. It is asserted that the flesh of animals suffering from tuberculosis and other diseases is frequently used in these preparations. Although in the case of tuberculosis the practice is very objectionable, there would seem to be little risk of the flesh of an uninfected part of the animal conveying the disease to man, and even when the disease was general thorough cooking would destroy the bacilli and probably the toxic substances pro- duced by them. There is, however, much more danger in eating the flesh of animals infected with the various bacteria that produce septicaemia, since their toxic products are only partially destroyed by heat. The flesh of animals suffering from anthrax, malignant cedema, and chicken pox is also dangerous whether in the raw or cooked condition. But this danger is one to which the consumer of fresh meat is also liable, whenever the system of inspection is defective. A greater danger in tinned meats than the presence of disease organisms and their products is that flesh contain- ing putrefactive products may have been used. Wholesale putrefaction of the contents of the tin would, of course, make itself known when the tin was opened, but this would not be the case if flesh in a state of incipient decomposition had been used, for the sterilising process would have arrested any further change. The meat in the tin might, in fact, be absolutely free from bacteria, and yet be poison- ous. The products formed by the bacteria are even more dangerous than the organisms themselves. Thus, in Ger- many, there have been wide-spread epidemics of what is known as butulism, a severe form of poisoning through eating raw or imperfectly cooked sausages. These have been found to be due to a definite toxine produced by Bacillus botuliiLus in flesh from which air is partially ex- cluded. This toxine has also been found in poisonous hams, but as it is destroyed by heat it is not likely to occur in tinned meat that has been properly sterilised. But there are numerous other bacterial products — the ptomaines — which, unlike true toxines, are not destroyed by heat, and it is to one or more of these that most of the not very frequent cases of poisoning by tinned meat can be attributed. Many of them are simple substituted ammonias, such as putrescine, C12H12N2, while others contain oxygen. Cadaverine, neuridine, and saprine are diamines, allied to pidresciiie, and, like it, are only slightly poisonous, but ■inrlli ijl-iiuin the " Umschaii," 1906, No. 8, the weekly journal of the work and progress of the eonihimd departments of Science and Technical Knowledge (Frankfort a./IM., H. Bechhold). Thi-. political newspapers and popular science journals are publishing accounts of the artificial generation of life and exciting universal amazement amongst their readers. The element of amazement arises, however, mainly from the interpretation put upon the matter by the imagination of the \\ riters of these accounts ; the experimenters themselves speak with considerably greater caution. .•\ccording to a communication in the English periodical Nature, No. 1,856, May 25, 1905, Mr. John Butler Burke sterilised some gelatine and placed it in a small tube with radium salt. After twenty-four hours there appeared on the surface of the gelatine a peculiar culture-like growth which gradually made its way down- wards into the gelatine. When examined under a microscope a distinct growth was apparent ; this was followed by subdivision of the circular bodies when they had reached a certain size, viz., 0.0003 mm., and they often took a rosette-like arrangement. Mr. Burke thinks the name Rudiobcs (Radium organisms) might be given to these bodies. I^rofessor Sims Woodhead asserted that their resemblance to bacteria is only an apparent one. He showed that the forms, when re- moved to fresh gelatine, increase still further in size, and that on heating the cultures till the gelatine dis- solves they disappear, but become visible again after a few days. Mr. Littlefield is stated to have obtained a similar result by quite a different process. To a 33 per cent, solution of common salt there was added the same volume of go per cent, alcohol. Small quantities of this mixture were placed in watch-glasses, a little ammonia was added, and the whole covered with a bell-glass. In lialf an hour drops were visible on a slide with the aid of a microscope. Crystals of common salt settled out first, then crystals from which emerged small oval or round forms which are alleged to be living organ- isms, since they grow, and, like amcebEe, send out mo\ing processes. But, assuming that the account of the directly ob- served results of these two experiments is absolutely correct, the conclusion drawn from them, that foims corresponding to living organisms have been obtained, is by no means justified. T/icsc unjustifiable eonelusious arise from the want of a eomplete definition of life in its simplest form. A quarter of a century ago I formulated such a definition f of living organisms on the ground of their peculiar property of self-preservation and the persistence of their species through the ages, notwithstanding alteration of ■ Translated by Miss E. Slater. ' "The Struggle of the Parts in the Organism," Leipzig, 18S1. Also in '-Collected Treatises on the Mechanics of Development," Vol. I., p. jSy. 1S95. material and environment, and I have recently more completely established this definition. ''' It is impossible to make a purely chemical definition of life, such as has long been sought, because life is intimately bound up with those physical aspects which are not merely the result of the chemical constitution, but rest also on a special physical structure. The definition of life can at present only be made on the basis of the activities of the living organisms, so far as we know them. Such organisms, at their simplest, are natural bodies which (i) absorb foreign materials into themselves {absorption), and (2) convert them into sub- stance resembling themselves, assimilate them [assimila- tion); (3) change themselves by means of processes taking place within themselvest {Dissimilation, e.g., consumption of albumen, fat, &c.), or, on the other hand, may reinain entirely or almost entirely unchanged (4) by spontaneous secretion of the altered material (secretion of carbonic acid, urea, &c., in animals, of oxygen, &c., in plants), and (5) by spontaneous repair through absorption and assimilation of food; and (6) may grow by over-compensation in the repair of the used-up material {spontaneous growth); further, (7) from causes lying chiefly in themselves they are able to move themselves {spontaneous movement, reflex movement), and are also able (8) to subdivide themselves {spontaneous subdivision, spontaneous multiplication), and (9) to transmit their characters entire to the organisms which spring from them {transmission). It remains to urge emphatically that all these long-known activities belong together, and that they are in their own way fixed, determined, in the organisms, even though their perfec- tion is often dependent on external factors, and though their activities are somewhat modified by external in- fluences. The sum of these activities is what deter- mines the character of the living organism, as well as the highly developed faculty of self-preservation. Living organisms are primarily concerned with the renewal and preservation of their species, and when food is present they take what is necessary to maintain their own exist- ence. Forms exhibiting the activities here enumerated would certainly be accepted as living organisms. But there is yet another essential property of all forms of life, even the lowest : (10) the spontaneous regulation of the exercise of all specific activities ; the more, for instance, they are deprived of food, the greater is their desire for it; when a certain quantity has been absorbed the capacity for absorption is diminished; the more foreign materials have been formed, the more possible is it to secrete them, &;c. By means of this power of regu- lating function, which, of course, is not without its limits, the faculty of self-preservation, and with it the persistence of the organisms, is substantially increased; indeed, when changes occur in external relations, this power is indispensably necessary in order to prolong existence. We must, therefore, regard the spontaneous regulation of function as a further " -primary property " • " Suggestions on the Mechanics of Development : I. The Mechanics of Development, a new Branch of Biological Science," p. 105. Leipzig, 1905. ] In the lower organisms dissimilation is not an absolute and continuous process as it is amongst warm-blooded animals, but it IS essentially conditioned by the using up of energy and the wear and tear of the machinery throjgh action. Many experiments made on cold-blooded animals, as for instance by drying and freezing, indicate complete suspension of metabolic changes. The continuous destructive decomposition of the warm-blooded animals, however, assists in self-preservation, since but for the maintenance of a higher temperature their machinery would not perform its functions and they would consequently be incapable of self-preservation. July, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 4«5 of the living org-anism. With it is associated also tlie power of adaptation to changing external relations (for instance, to change of the accessible food supply) and, amongst higher forms, to changes of climate, to changes of habitat, to or from a flat or a mountainous region; that is, to the consequent alteration in the mode of life and in the various instinctive activities. It is only by means of this power of adaptation that self- preservation becomes possible in the face of changes in these relations. Since all this adaptability (conformability), as it is called, in the activities of the organisms, serves only to prolong their existence, it is more appropriate to speak of the persistence than of the adaptability of the organisms, and to speak of their recuperative and pro- gressive activities rather than of their adaptable activi- ties, a suggestion (v. No. 1, p. 214) accepted by vari- ous authors (eg., Ostwald) and attacked by oil.eis (e.g., Kd. v. Hartmann). No form which does not exhibit all these activities can be described as even the lowest kind of living organism. But where these exist we need not concern ourselves with their origin or special chemical and physical nature. It is, however, essential that such forms should, in addition, possess special properties in order to continue their existence on the earth. They must, for instance, be insoluble in water, since they would otherwise be liable to be destroyed by the fre- quent rains, and so would not be able to persist through the centuries nor reach any further stage of develop- ment. The higher organisms possess, in addition, many other properties, as, for instance, the power of as- suming various forms (the spontaneous development of all characteristics of class, genus, species, &"c.), and the manifold psychological activities, all of which are deter- mined according to the substance of the organisms, but do not now concern us. To emphasise once more the essential point; the organisms participate in the renewal and preservation of all their special " typical " mechanisms of self-determination and self-preservation, as well as in the production of the outer factors which are determined from within; that is, which depend on their own physico-chemical structure. " Typical " in this definition is a more strictly limiting conception than " normal," which has hitherto been adopted ' Turning now from what is known to the experiments of which mention has been made, let us ask whether the forms produced in each of the two experiments present all these primary activities of life. Of Burke's forms it is only asserted that they grow and subdivide. We must, in the first place, enquire whether this growth is " spontaneous growth " ; in other words, whether it takes place in accordance with the characteristic growth of the organisms by means of new living substance formed in and by the organism itself, by assimilation of other materials within the organism, and not, like crystal growths, consisting of accretion of external materials surrounding it, even though these materials have been produced by the in- fluence of the form itself, or whether it depends only on a propagation of this influence, like the propagation of warmth, or of diffusion. In the second place we must ask whether the sub- division of the forms which has been observed is reallv spontaneous subdivision, and whether it takes place by means of influences which are determined within the organism in accordance with its nature. On this point nothing is said, but it may, perhaps, be the case. It • See No. 2, p. i8i. may, however, be remarked that apparent subdivision takes place under many conditions. For instance, if w-e place a drop of alcohol on water, or a drop of oil on a solution of soda, the drop divides very quickly, and apparently spontaneously, into four parts; in reality, however, it is divided by the influence of the surface tension. Nor is the rosette-like arrangement peculiar to or characteristic only of living forms. It will be seen at once that the main point is absent in the " observed " activities of Burke's forms; the proof, namely, that these activities correspond to the same activities in the lowest forms of life, that they are, in fact, " spontaneous activities " of the organisms. Be- sides, it is not probable that the mechanism of the two very different "organic " activities, assimilation and spontaneous subdivision, could be effected in so direct a manner; that is, by the direct energy of radium alone. But even if this were possible and had here taken place, these forms might still be considered as very interesting preliminary stages of life, as " probionts " (Probiontcn), but not as representing even the lowest forms of life, for they are without the activities of spontaneous dis- similation, of spontaneous secretion of changed materials, and of the spontaneous movement which is characteristic of living organisms, as well as of the -spontaneous regulation of the performance of all activities. Although the results of Littlefield's experiments are said to be different from those of Burke's, they are yet less inconclusive as to the artificial production of living forms. I have repeated these experiments and obtained results which in many ways apparently correspond to those described, but I ascribe to them a wholly different significance. On the saturated ammoniacal solution of common salt in alcohol many small separate forms appeared moving hither and thither. But scraps of filaments arising from the impurity of the liquid floated about in the same direction, thus showing that the movements of the individual forms are not active, but passive, de- pending on the motion of the liquid. This, however, is by the way. On the evaporating circumference of the drop, crystals separate, many of which have an area of liquid which has either been left on them or has possibly caught on them or has run over them. Thus we have forms which closely resemble cells. The liquid area mav also have processes which, in consequence of further drv- ing or of the altered surface tension, change their form and so present the appearance of slow amoeboid move- ment. But in all these it is only a question of forms arising from unequal moistening capacity of the glass, or its unequal surface and unequal surface tension. Anyone can produce similar forms to any extent by pouring water over a glass plate held obliquely; after most of the water has run awav such forms are visible to the naked eye. If there are on the glass plate small unevennesscs or dusty spots which are more easily moistened, the liquid collects on these parts, and on looking at it from above we again have the cell form with the nucleus in the middle and processes outwards, the latter of which change their form on further con- traction or moistening. These well-known phenomena show that forms may be produced resembling amoeba?, but without their essential characteristics. Besides, the motion of amoeba; often depends on alteration of sur- face tension through external causes. But in the case of their spontaneously regulated movements the move- ment is produced from within and is definitclv charac- terised. Moreover, numerous pale yellow, very small and 486 KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. round, or oval and flat disc-like forms were noticed, sometimes near these liquid area crystals, sometimes at a distance from them; these are probably Littleficld's organisms. To me they appeared to be residues left after evaporation, or deposits on dirty places on the plate. I'erhaps they are partly produced like the flat drops which may be seen forming- on the side of a vessel only partly filled with alcoholic liquid. Alcohol first rises invisibly, and gradually becomes visible on the sides; perhaps even a mist is deposited at a suitable temperature; in this way drops are formed which gradu- ally increase in size; other drops are formed in the same way all about them, often appearing to issue from the earlier ones. These are well-known phenomena which, however, have nothing to do with specific organic " spontaneous growth." I have never seen any growth in the small pale forms which arise in great numbers as the evaporation proceeds, although I do not assert that such phenomena are impossible, for we know that in- stances of the kind may be found in similar artificial forms. The deposited drops just mentioned increase in size visibly; this, however, is not spontaneous growth, but passive growth, according to my definition. On large freshly-moistened glass surfaces division of the liquid used for moistening is frequently seen. This division is caused by retraction of the layer of liquid at some points of closer adhesion. It is not, however, spontaneous division, but is division " effectuated " and determined from wiihout and influenced by the exact degree of surface tension, and is not connected (through qualitative bisection) with transmission. We often can produce no direct, but only indirect evidence of assimilation and of the spontaneous growth which depends upon it, as also of spontaneous division, in the actual lowest forms of life. In order to adduce direct proofs of assimilation it would be necessarv to watch for days together to see that materials differing in appearance were taken into the organism, that these did not accumulate in large masses different from the rest of the organism, but gradually disappeared. Even then assimilation is only indirectly proved bv the fact that the vital force, instead of being reduced by taking in so much foreign material, is, on the contrary, in- creased, inasmuch as subdivision of the organisms goes on. If this subdivision has gone on through several generations, and has always resulted in forms re- sembling the original in shape and function, then we have a clear proof of spontaneous assimilation and of spontaneous division. The actual lowest forms of life exist for the most part in aqueous fluid and prove by the fact of their re- maining intact that they are not soluble in it. The artificial forms spoken of, on the contrary, are soluble in water; they are incapable of maintaining their exist- ence in it, and in this respect also they are lower in the scale than living organisms-,* ♦ While this paper was in ihe press there appeared ^in ihe Karlsruhe Journal) another commuri. ation en the same subjftt giving an account of some interesting observations made in the Physical Institute at Karlsruhe under the famous physicist O. Lehmann ; it was also widely circulated under the misleading title o( " A New Physical Wonder." It gave an account of drops which form buds and divide, then assume a worm-like shape and ,-ifterwards separate into many parts. They crawl about like the Hiit'chli drops mentioned, but more quickly. These forms, •uhich seem to be produced mainly by changes in surface-tension in a manner which makes them appear almost typically peculiar, must also be tested as to the degree of their resemMance to living forms by the analytic method of examining functions given above; and the nature of the forres in question must be narrowly scrutinized and compared with the influenceswliich have produced organic phenomena of a similar kind. I'erhaps here we shall come upon the beginning of that spontaneous division which is essentially determined from within. We have recognised, then, on the one hand, that the artificially-produced forms are devoid of the primary activities essential to even the lowest forms of life; and on the other hand thi re is no proof that the activities observed depend on the power of spontaneous deter- mination which is characteristic of living organisms, or that they are capable of that spontaneous regulation which alone would enable them to persist throughout many changes in external relations. '1 he inadequacy of the dcjnutions of the nature of life formulated and promulgated by philosophers, natural- ists, and even some physiologists, is ultimately responsi- ble for the unwarranted interpretation of these forms as being actual organisms of the lowest stage. They think that what is needed is something simpler, more universal, more direct, than what I have given above, the sum of widely differing individual activities and tho spontaneous regulation of these. Even if we leave out of count those authors who take the supernatural view and would have a " purposeful agent " (conscious First Cause) in the processes which result in life, yet we cannot disregard those who believe there could be a " simple " chemical process or a simple physical agency which could produce all these activities. According to this view a " simple " experiment might happen to pro- duce this direct agent and thus suddenly give rise to forms of life. But there is a fundamental error in this view. The sum of the different activities descriljed above alone indicates the minimum of actual life, and only those forms which possess this sum of activities reproduce similar forms; nor does this reproduction de- pend on the aid of a purposeful agent, but, the forms once in existence, reproduction depends only on the pre-determining tendencies inherent in their material basis. Admitting all this, however, it would be vain to assert that in principle we could never artificially create the lowest forms of life, perhaps with very slightly deve- loped spontaneous regulation. This, however, cannot be done by a single experiment, but only by a methodical scries of experiments in which we must first endeavour to produce forms with one or a few primary individual activities. The insight which has been gained can be turned to account by combining the successful results already secured. Only thus shall we be able gradually to produce bodies which will combine all the activities indicated above wliich are necessary for self-preservation by the processes of change in material corresponding to change in external circumstances, and which will then con- tinue and multiply. Forms possessing certain of these activities, spontaneous movement, spontaneous absorp- tion, and spontaneous secretion of material, have already been artificially produced by Butschli, Quincke, Rhumbler, and others. Spontaneous chemical assimila- tion, spontaneous growth, spontaneous secretion of altered material, and a certain amount of spontaneous regulation in assimilation and secretion are typically represented in the processes of assimilation by heat. Since, however, the other activities of self-preservation are absent in bodies thus produced, their power of per- sistence is inadequate. As soon as cold assimilation processes of a suitable nature (according to l-'fliiKer, cyanide compounds) are employed, it is possible that high preliminary stages of life might be produced artificially by combining these with the processes for the last-named forms. Spontaneous division, spon- taneous regulation, and " morphological assimilation," which presents special difficulties, would then follow. We shall then, perhaps, attain in the laboratory by observation and study in a relatively short time to what in nature has only arisen in the course of vast periods July, 1906.] KNOWLEDGE & SCIENTIFIC NEWS. 487 of time as the result of a fortuitous concurrence of cir- cumstances and of a spontaneous storing- up of the forms capable of self-preservation through changes in material and thereby of " persistence." If, then, it is certain that the above-mentioned ex- perimenters ''' have produced no actual forms of life, even of the lowest order, and have not solved the problem of the artificial creation of life, and if this problem cannot be solved bv one kind of experiment alone by reason of the number of primary life-activities necessary even to the lowest organism, we must assume that further research will be necessary in order to ascer- tain how far the various experiments of these writers are a new and valuable contribution towards the solving of this problem by the slow method insisted upon above, namely, the combining of artificially produced individual activities f- * Including Charlton, Bastian, Stadelmann. (MS. note.) I This is practically the argument used in The Origin of Life which which has just been published. I do not think however it is likely that we shall succeed in producing artificial forms of life which would correspond to the organic types existing naturally in nature. The probability of hitting on the exact conditions would be infinitesimally small. The most we can hope to do, as I have tried to show, is to imitate these by approximation. The artificial types, of course, do not satisfy all the conditions of niitiinil life, it all depends, therefore, upon what we understand by life. If a scale of gradually increasing complexity can be established, from the supposed inanimate to admittedly animate nature, there should be no reason why we should confine the definition of life to natural types which have survived on account of their fitness for their surroundings. As a curve may approximate to its asymptote, so may artificial life approximate to natural life. But as the latter is the survival of countless generations, it is likewise to be expected that it should be more perfect than anything that by artificial means we should ever hope to obtain. I believe the subdivision cf the radio organism proceeds from the interior, as I have tried to show, and that the growth is not by accretion, but by assimilation, as in the case of most organic crystals. They appear to assimilate sulphur and other substances frorri the medium in which they grow. The Hedjaz R^ailway. 15y P. L. .ScL.ATER, D.Sc, F.R..S., I<-.R.G..S. .So httlo i.s known in Western luirope .-ilioiit the " Hed- jaz Railway," which has been planned witli the object of conveying Mahometan pilgrims direct to Medina and Mecca, :ind so saving them the dang-er and toil of a long overland journey, that some information on this rather mysterious subject may not prove unacceptable to the readers of " Ivnowledge. " livery Mussulman, as we know, is bound to imder- take the pilgrimage to Mecca once in his life. .\nd this pilgrimage properly begins at Damascus, where the holy tent is kept, although few pilgrims nowadays, ex- cept those who live in the district, go round by Damascus and perform the journey of 27 days over- land, w-hen Ihey can be conveniently carried by steamer to Djedda, which is only 45 miles from the Holy Citv. The pilgrim.ige-caravan leaves Damascus with great ceremony once a year, at a period varying according- to the Mohammedan calendar, and procei-tls by the great pilgrim-route to Medina and Mecca. The ijilgrini-route (Derb-el-IIejji) is marked on most maps, and the railway, I believe, follows it very closelv. The exact inventor of the clever scheme of construct- ing a railway along the pilgrim-route from Damascus to Mecca is not known, but in Turkey is commonly sup- posed to have been (he Commander of tin- Faithful him- self; and this may -well be the case, for the present Sultan is one of the most wary and capable of crowned heads, especially in matters relating to his own sovereignty. It'is obvious that a railway made pro- fessedly to carry pilgrims would also be available to transport soldiers and military stores. And both these articles are n-iuch required in Central Arabia, where the continued and successful rebellion in \'emen has long been a source of g-reat anxiety to the Sultan and his advisers. However this may be, in May, 1900, it was announced in one of the official journals of the Turkish Empire that a railway was to be made from Damascus to Medina and Mecca, and the whole Mahometan world was in- vited to contribute every possible assistance to this pious work. This good news was trreatly appreciated /SYRIA '^-^^''-'-t--?^ B^yrcuy^ DAMASCUS Haifa/3AJ jMzalrcb Medina Hedjaz. Railway V. open -CJ-C-— \ DjeddaWiMEcCA by the Mahometan press, and was spread abroad not only o\er Turkey, Egypt, and .Arabia, but throughout the eastern world where there were adherents of the Islamite faith. The great advantages of the new scheme, religious, political and economical, were duly dwelt on, and the Hedjaz Railway was lauded a.s of equal importance to the Suez Canal. To commence the work six Mussulman engineers were assembled (not without some diHiculty), and despatched to Damascus to make a preliminary survey, and it was agreed that all mtiterials for the holy project should be stipplied exclusively bv Mahometan factories. Three new railway-battalions of soldiers, each a thousand strong-, were raised to act as " navvies." But it was soon discovered that, though tlie Turks might be eOicient as navvies, they could not make rails or build locomotives and trucks, and it was found necessary to go to Belgium and Germany for a supply KNOWLEDGE & SCIENTIFIC NEWS. [July, 1906. of these requisites. It was also quickly shown that the native engineers were useless, and their places w-ere taken by Europeans from Italy, France, and Poland. A German engineer, Hcrr Meisner, was placed at the head of the railway-corps. (ireat efforts were made to raise the monev required for this gigantic task. The Sultan set a good example by giving up a month of his civil list, amounting to 50,000 Turkish livres, and a tax of 10 per cent, on all salaries was levied in aid of the undertaking. Besides this, large donations were received from all parts of the Mussulman world, especially from India and Ceylon. Mirza Ali Bey, of Calcutta, sent a donation of ;£'5,ooo to the holy work, and promised further advances, and large sums were also received from Australia, Singa- pore, and Natal. On September i, 1901, being the 26th anniversary of the Sultan's succession, the first portion of the new line (about 20 kilometres, between \izaireb and Dera) was opened with great ceremony. Other portions followed suit from time to time, and the main line from Damascus to M'aan, a place about half-way between the south end of the Dead Sea and the north end of the Gulf of Akabah (conveniently near to the famous ruins of Petra), was sufficiently finished to carry slow traffic about a year ago. The length of the line, as shown by the subjoined list of the stations (kindlv supplied to me by Messrs. Thos. Cook and Son), is 465 kilo- metres. Since then (as we were informed bv the corre- spondent of the Titties at Constantinople in December last) the line has been carried on for a further length of 150 kilometres to Mudavara, and it has been deter- mined to build a branch line either from that place or from M'aan to the head of the Gulf of Akabah. But a still more important event in connection with the Hedjaz Railway now remains to be mentioned. To connect the great city of Damascus and the fertile country around it with the civilised world two railways were originally planned — a French line to start from Beyrout and cross the Lebanon and Antilebanon, and an English line commencing at Haifa and crossing the Jordan south of the Sea of Galilee. The northern (French) line was quickly carried out, and for some years has been the established route to Damascus. The southern (English) line, ill-provided with funds and not in favour at Constantinople, has nev'er prospered, and only a few miles of it out of Haifa were ever opened. Abdul Hamid realised the situation, and after a long bargaining with the concessionnaires, succeeded in buy- ing up the undertaking and completing it from Haifa to Dera, a station on the Damascus-Mecca line, 123 kilo- metres south of Damascus. The Sultan will thus be able when the whole project is completed, to ship his pilgrims (or soldiers !) at Haifa and run them straight to Medina and Mecca. This will not only save the passage of the Suez Canal, which, as being under Anglo- Egyptian control, is not favoured by the authorities at Constantinople even for pilgrims, but will also enable troops and arms to be sent to Central Arabia without any risk of their bemg stopped or delaved in Egjpt. I am not much in .sympathy with the Turk and his ways, but in the case of the Hedjaz Railway I think he has done a good work and deserves success. It may probably be some years before the line is completed to Medina and Mecca ( !), but in the meantime a country very little known and hitherto very difficult of access has been opened up, and Petra and manv other ancient sites along the route which it traverses will be rendered comparatively easy of access. Messrs. Thos. Cook and Son inform me that they are making arrangements wherebv travellers will be able to visit the wonderful ruins of Petra by the Hedjaz Railway from Damascus to M'aan during the next season in Palestine. There can be no doubt that the recent occupation by the Turkish forces of one of the ports at the north end of the Gulf of Akabah which is now producing much friction between the Egyptian and Turkish Govern- ments, is caused by the anxiety of the .Sultan to find a suitable opening for the Hedjaz Railway on that Gulf. If this can be secured the Porte will be able to send its troops and stores into Central Arabia without going through the Suez Canal, which might be closed at any moment in case of war. of the stations on the Hedjaz Rai way : — Distance from Damascus in Kilometres. Kaaden esh Shereef (Damascus) El Kieweh 20.80 Deir Ali 30.50 El Miemiveh ... 49.70 jebab 62.60 Khubeb 69.10 Mabje 77.80 -Shakra 84.50 Ezra (Zorca) 91-25 Kharbet el Karaly 106.10 Dera 123.00 (Junction with the line from H aifa) Nassib 135-35 Mifraka (Kelaat el Mefraak) .. 161.70 Kharbet es Samra 185.30 Zerka (Kelaat es Zerka) 202.75 .Ammon 222.40 Kasr el Ala 234-05 Leben 243-50 Djira ... ..'. 259-70 Dekaa 279-15 Ez Zebib 295.70 Katranek ... 326.60 El Khassa (Kalalel Hassi) 378.25 Jeroof ed Derursh (Wadi Henna) 397-80 Aneiza 425-25 M'aan 465.00 -i^^^^r* Plants and Frost. .According to Professor A\aegand, of Cornell University, it seems probably that frost causes the death of vegetation by causing the actual withdrawal of water to form ice nutside the cell. The ice formation dries out the cells, and the plant suffers therefore from drought conditions. Every plant cell has its critical point, the withdrawal of water beyond which will cause the death of the cell, whether by ordinarv- evapora- tion or other means. It may be supposed that the delicate structure of the protoplasm necessary- to constitute living matter can no longer sustain itself when too many molecules of Nvater are removed from its support. In the great majority of plants this point lies so hieh that it is passed very soon after ice beerins to form in the intercellular spaces. Hence the death of so many plants at this point. But other plant cells may be able to exist with so little water that a very low temperature is necessary before a sufficient quantity ^s abstracted to cause death. From some plants enough water cannot be abstracted by cold to kill them (many bacteria, it will be remembered, can endure the cold of liquid air). In rather dry tissues, as in some winter buds, a temperature twenty to thirty degrees below freezing may be required before the ice crystals can be seen in the tissue. July, iqo6 1 KNOWLEDGE & SCIENTIEIC NEWS 489 REVIEWS OF BOOKS. ASTRONOMY. Radcliffe Catalogue for 1900 ; of 177^ Stars, chielly com- prised wkhin the zone 850 to 90" N.P.D. (Oxford, 1906, xxxvi. + 81 ; 15s. net). — This vo/ume, published by order of the Radcliffe Trustees, under the direction of Dr. Rambaut, the Radcliffe observer, contains the results of ten years' meridian observations with the Radcliffe transit in- strument, formerly used by Carring^ton. Of the years in question, 1894 to 1903, the first two were mainly devoted to finishing off the previous Radcliffe Catalogue for iSgo, and the last to dotting the i's and crossing the t's of the present one. The quantity of observations, e\-en if wholly confined to the seven remaining years, is not by any means large, but it should be borne in mind that the staff is small, and has much other work to do, and that serious interruptions were caused by the death of E. J. Stone in 1897, and the appointment of his successor, who was, perhaps, inclined to be too sceptical as to the value and validity of his pre- decessor's Vk'ork. Most of the stars in the present catalogue are to be found within the zone 850 to 90", N.P.D., and it also contains all the stars legitimately included in the Nautical .Almanac Zodiacal List. (N..\., 1897.) It might at first sight be thought that Dr. Rambaul's re- mark on the first page of the introduction, as to the number of stars in the catalogue, is a rather clumsy paraphrase of the possibly sarcastic statement, " The observations, t/ioiig/t few, are good." The real meaning of the sentence is that the observers did not endeavour to work against time, as they might have been tempted to do. .Alterations were made in the floor of the room to increase the stability of the instrument, and various other improvements intro- duced into the system, notably a chronograph. It is not clear that the substitution of a circular mercury trough for reflection observations of stars is an improvement, as the dimensions are not given. For nadir observations, where the advantage of a circular trough is less questionable, the old rectangidar one is still in use. It seems obvious that unless the circular trough is very large, its use for low stars is a great mistake, and if low stars were not observed, is it not surprising that the R-D discordance should be regarded as unsatisfactory.' Very few stars were observed for Colatitude, so that it is quite likely that all the cata- logue comparisons ai the end of the introduction are systematically affected. It appears certain for instance, that the comparison with Grecnwicli, ISOO, from which Dr. Rambaut professes to cast doubt on the vnliditv of the Greenwich RD correction, is erroneous, since the adopted colatitude at Greenwich is affected by RD, and this point, as well as the effect of substituting Pulkowa refractions for Hessel's, seems to have escaped the RadclilTe observer's notiee. There is a description of the determination of pivot- errors by a method devised by Dr. Rambaut, founded on that of M. Hamy, of the Paris Observatory. There is also a defence of electric control for chronographs, which, how- ever, is not satisfactory, as it assumes that there is no lag in the changing speed gear, and that the observations are all read in accurately by proportional scale, which, though desirable, is only attainable when the number of registered observations is comparatively small, or the computing staff large and not busy. Our readers must not infer that we are objecting to the electric control so much as to the defence of it. Several pages are devoted to a discussion of the division errors of the circle, which leave the im- pression of a great waste of time. Stone's errors being under suspicion, the observations on which they were founded were re-examined, without the light of the know- ledge as to their relative value, which Stone undoubtedly possessed, but did not record, with the natural result that by giving equal weight to most of them, a different set of corrections was obtained, and the also natural result that the differences were slight. Whereupon, as the old cor- rections were already in use, no change was made. It is difficult to see what change could have been made without repeating the observations themselves, as it could hardly be Stone's powers of computing that were under suspicion. We ran appreciate the determination not to waste more time by altering the corrections, better than we can ap- preciate the devoting of several pages of introduction to the account of the investigation. Very few of the funda- mental stars seem to have been really well observed in X.P.D. Possibly it was in this one unfortunate direction that the observers were encouraged to save time. In one place. Dr. Rambaut says : " The results are of a high order of accuracy, as is shown by the tests which have been applied," i.e., the probable error is small; in another place he says : " The smallness of the probable error correspond- ing to the zone lao' to 122°, is obviously an accident, due to the small number of stars which it contains." .Are we to infer that the probable error of a single observation must be zero, or that the probable errors of the catalogue are small because the stars are few ? Nearly all the stars in the catalogue have been observed three times at least in each element. Among the very few e.xceptions, we notice Sirius with only two observations. It seems a pity such a star was included at all, if so few observations were made of it, especially as it involved corrections for orbital motion and parallax. Reference numbers are given for each star to Auwers' Bradley (1755); Lalande (1800); Weisse's Bessel (i), (1825); Albany, A. G. (1875); Radcliffe (1890); Greenwich (1890); and Bonn Durchmusterung (1855), and notes are added on magnitude and colour, and authorities given for the adopted proper motions. We have nothing but praise for the general style and appearance of the volume, which is similar to the Radcliffe 1890 Catalogue. It will be interesting to compare the results with other catalogues of the same epoch when they appear, a time which should be fast approaching. BIOLOQY. The Dynamics of Living Matter, by J. Loeb, Columbia University Zoological Series (New York and London, 1906; pp. xi. + 233, price 12s. 6d. net). — Two transcendental problems, observes the author, confront the biologist at the present day, namely, the artificial transformation of dead into living' matter, and the artificial transformation of one species of animal or plant into another. As to the first problem it is certain that no one has yet witnessed such a transformation, but since we daily see animals and plants converting dead into living matter in their own tissues, and since chemical processes are essentially the same in living and in dead matter. Professor Loeb does not despair of the discovery of abiogenesis, and urges that this should be the goal of every biologist. Incidentally he raises the question whether death is a necessary outcome of development, and whether rejuvenation and the commencement of a new cvcle are impossible. .As to the second problem, this has undoubtedly been solved by de Vrics's famous experiments of primulas, and, if plant-species can be artificially produced, why not animal species? The chemistry of living organ- isms, the general physical constitution of living matter, the more important physical manifestations of life, the influence and effects of electricity, heat, and light upon living matter, the phenomena of " heliotropism " (turning to the sun), the nature of fertilisation and regeneration processes form the subject of the various chapters (originally lectures') which go to form this thoroughly philosophical, and at the same time thoroughly practical, work, which cannot fail to raise the already high status of the scries to which it belongs. BOTANY. Methods in Plant Histology, by C. J. Chamberlain, A.M., Edition II. (I'islur L'nwin, iqot); los. 6d. net). — The first edition of this book, written by a teacher of botany con- nected with the L'niversity of Chicago, was very favourably received in this country on account of its sterling merit ; the present edition embodies all the reliable laboratory methods that have been discovered during the interval of four years. The collection and preservation of material, very important features, and on which further research almost entirely depends, receive special attention. Methods of growing laboratory material are also clearly outlined. The almost endless variety of reagents and stains cata- 4 go KNOWLEDGE & SCIENTIFIC NEWS. [July, iqo6. logued by dealers are apt to bewilder the student, and lead to much loss of time and vexation of spirit. A careful perusal of the book under consideration will, however, clear awav such difllcultics, as only those materials that have proved most suitable for specific purposes are indicated. A special chapter is devoted to the comparatively new method of making permanent preparations in Venetian turpentine, which is stated to be much superior in results to the well- known glycerine method. The subjects indicated above occupy about one half of the book, the remainder being devoled to an introduction to the study of forms which, while serving for practice in microscopical technique, will also furnish the student with preparations including a general view of the structure of plants, ranging from the alga; up to the angiosperms. The book will well repay the time expended on a careful perusal by every teacher of botany, however much experienced. A Text ■ Book of Botany; Part I., The Anatomy of Flowering Plants, by iM. Yates (\Vhittaker and Co. ; 2S. 6d. net). — The author has obviously yet to learn what anatomy ineans ; the only attempt to deal with anatomy in the book defines " A Medullary Sheath, consisting of spirally-shaped vessels round it." The book consists in realitv of a string of attempted definitions of the various organs of plants, illustrated by what, for want of a more expressive name, must be called figures. Up to the present, botanists have been reticent when pressed for a concise definition of a cone. Here, we are told that a cone " is a