1063

obtained in a nascent condition attacks platinum, and pro-duces platinum tetra-fluoride Pt F4 ; and this probablyunites with potassium fluoride to form a double salt analogousto the well-known platinic chloride 2 K Cl, Pb Cl. It is onlywhen the liquid contains this double salt that the electrolysisproceeds in a regular manner, yielding gaseous fluorine atthe positive pole, and hydrogen and a complex compoundcontaining potassium, platinum, and fluorine, at thenegative pole. Fluorine possesses an odour which M. Moissancompares to a mixture of hypochlorous acid and nitrogenperoxide; but this odour is usually masked by that of ozone,which is always produced in moist air. Fluorine producesserious irritation of the bronchial tubes and mucous mem-branes of the nasal cavities, the effects of which are felt forquite a fortnight. At a temperature of 95°, and underordinary atmospheric pressure, fluorine remains gaseous.Probably no element exhibits a more intense chemicalactivity than fluorine. It combines with hydrogen even at23°, and in the dark with explosive force, this being the firstinstance of two gases uniting directly without the inter-vention of extraneous energy. Whilst not apparentlyacting on oxygen even up to a temperature of 500°, itappears to exert some action on ozone. When a few dropsof water are placed in a suitable apparatus, and fluorine isallowed to enter, the water is instantly decomposed, and athick dark cloud is seen to appear where each drop of waterhad previously existed. This cloud soon diminishes inintensity, and is replaced by a beautiful blue gas, which is,in fact, ozone in a state of considerable density. Nitrogenand chlorine do not appear to react with fluorine. Sulphurrapidly melts and inflames. Bromine and iodine combinewith fluorine with the production of flame. Whenphosphorus comes in contact with it, a most lively actionensues, accompanied by vivid incandescence. Arsenic com-bines in a similar manner. Although chlorine does notunite with carbon, even at the temperature of the electricarc, fluorine reacts at ordinary temperatures with finelydivided carbon. Boron inflames instantly, and gives bril-liant sparks; while the action between fluorine andsilicon is described as one of the most beautiful of allthese extraordinary manifestations of chemical activity.Cold crystals of silicon become white hot, and burn witha hot flame, scattering showers of star-like white hotparticles in all directions. The residue is found to befused, which, as crystalline silicon only melts at a tem-perature superior to 1200° C., indicates a very intenseheat. Potassium, sodium, calcium, thallium, magne-sium, iron, aluminium, chromium, manganese, antimony,lead, mercury, copper, silver, gold, and platinum, are allacted upon by fluorine, and in many cases the action isaccompanied by vivid luminosity. Non-metallic compounds,like sulphuretted hydrogen, sulphur dioxide, hydrogenchloride, hydrogen bromide, hydrogen iodide, hydrogennitrate, ammonia gas, phosphoric acid (burns with paleflame), arsenious oxide, carbon disulphide, and boric acid(incandesces vividly), are readily decomposed by fluorine.Silicon dioxide (pure quartz or flint), one of the mosiinert of substances at ordinary temperatures, takefire in the cold in contact with fluorine. Carbon tetra-chloride, however, reacts slowly, but a mixture 01

the vapours inflames spontaneously. Fluorine acts or

metallic compounds, such as the chlorides, bromidesiodides, cyanides, and sulphides, and on potash and limewith more or less intense energy. Sulphates, nitrates, an(phosphates require the application of varying degrees oheat, when they, too, succumb to rapid and energetic decomposition. The action on a few organic compounds habeen studied. Chloroform, with an excess of fluoriniexplodes, and the tube is shattered in pieces. With Ilimited quantity carbon is deposited and fluorides o

carbon and hydrogen are evolved, together with chlorineMethyl chloride behaves similarly. Alcohol takes firlwith explosive violence without deposition of carbonwhile aldehyde is formed to a considerable extent. Acetiacid, benzene, and aniline are also decomposed, the first twwith violence, and the last accompanied by flame. Suc:are very briefly the results of the more recent researcheof M. Moissan, and, as Professor A. E. Tutton puts it inconcluding paragraph of an article in last week’s Nature (twhich for a fuller account we would refer our readers), " thecannot fail to impress those who read them with the pr<digious nature of the forces associated with those minutest <

entities, the chemical atoms, as exhibited at their maximunin so far as our knowledge at present goes in the case of tlelement fluorine."

THE BREWERS’ EXHIBITION.

THE Brewers’ Exhibition may be said to have " a shortexistence and a merry one." Its doors are opened for onlya week, and, seeing that the bulk of the exhibits are of verygeneral interest, one is led to wonder why the authorities do.not permit it to have a longer 6 run." The brewing and’mineral water trades are of course mainly represented, but,these bring in their train a host of auxiliary subjects whichmay prove of interest to many of the readers of THE LANCET..Such are, for example, the preservation of beer and wines,.antiseptic treatment., filtration, new brewing materials,new non-alcoholic beverages, improvements in the bottling*of non-alcoholic beverages, and certain sanitary pro-cesses connected with the manufacture of both mineral’waters and fermented liquors. The display of mineral’water machinery is as a rule watched with the keenest,interest. In the excellent show of Messrs. Barnett andFoster, for example, the marvellous machine for filling:patent bottles attracted considerable attention. The bottlesto be filled are fed by means of a trough on one side,syruped, filled, and delivered into a return trough back te,the operator, ready for putting into boxes at the almostincredible rate of from 130 to 150 dozen per hour. The-same firm exhibited a device by means of which the ordinaryglass marble. stoppered bottle can be more easily and con-veniently opened. The opener is attached to the bottle,and simply consists of a small hoop of wire which acts as a.lever to raise the indiarubber ring and so release the pressure.It is only necessary to press the opener well over with thethumb, when theglassba.11 falls and the wire retains its formerposition. Some interesting and important improvementsia syphons were shown on this stand. One noteworthy im-provement consists in providing the glass tube with a checkrubber valve, so that the outflow does not come out with a,

rush, but in a steady stream, retaining the gas, and securinga draught of soda from a syphon equal in sharpness to that,taken from a highly charged soda bottle. However sud-denly the lever may be pressed, the liquid cannot rush outwith a rude splash, as is frequently the case with the ordi-nary syphons. Messrs. Bratby and Hincliffe showed a.

machine specially constructed for semring thorough impreg-nation of water with carbonic acid gas. This machine dis--plays much ingenuity, and is so made that the water to becharged is forced through a number of tiny holes (whichwould hardly permit of the passage of a pin’s point) into acopper cylinder containing gas under very high pressure &deg;the water is then forced into a similar cylinder at 80lb.pressure, and ultimately driven to the "power turnoverfilling machine’ of the same firm. Messrs. Dan Ry landsexhibited several aerated water plants of sizes to producefrom 600 to 3000 dozens per day. Their patent glass-linedtubing for mineral water manufacture and for watermains and service pipes is not without interest. Itis said to be an absolute preventive of lead or

other metallic contamination. This firm also showed a.

simple compressed sponge filter, which is recommended forthe removal of suspended matter in liquids. The verticadrefrigerator of Messrs. Robert Morton and Co., for thecooling of brewers’ and distillers’ worts and other fluids, is.

- worthy of notice. The refrigerator is made of a series of, hand-drawn copper tubes, through which a steady stream of. water is constantly passing. The fluid to be cooled is.I allowed to trickle down the immense surface of tubing,; reminding one of the system used for heating the watert in locomotive boilers. Refrigerators are made, it is stated,

to cool one hundred barrels per hour at a minimum cost.., There was a goodly array of non-alcoholic drinks. Amongst,; those noticed were the excellent productions of the Pur&, Water Company, including recent additions in the form of

Kola champagne and Kola liqueur; Kops’ ale, said to be) brewed from the best Kentish hops and absolutely non-i alcoholic ; Cox and Company’s "Antiburton" and hops bitter ale, the latter being a first-rate imitation of ordinarybrewed liquor ; and the Twin Bottle and Bottling Company’so beverages. The latter call for brief description. Two

bottles are lashed together, one being moulded to the shapeof the other. In one bottle is, say, soda-water, and in theother perhaps tea or coftee infusion or claret. The two

, liquids mingle, of course, when poured into a glass,e and a more or less agreeable drink is obtained. The

following filters were exhibited : The Berkefeld Kiesel-

1064

guhr Filter, already fully described in Tim LANCET ;the Idiocathartes Removable Plate Water Filter; Bar-&bgr;tow’s Combination Natural Stone and Carbon Filter, inwhich a natural stone lining is the main novelty; theRapide of Messrs. Maignen and Co., and the filter of H.Rawlings, in which twice burnfd and specially preparedanimal charcoal is used-a point of some interest andimportance, as it is stated that ordinary animal charcoalis seldom free from unburnt organic matter, and this hasnot improbably brought it hitherto into disfavour. " CumGrano Salis " is the name given to a hardening powder forthe treatment of water destined for brewing purposes,and deficient in saline constituents. It is well knownthat the hardness of Burton water contributes in no smalldegree to the esteemed character of the beer there pro-duced. The Bucket Fire Extinguisher, though it cannotclaim to have any direct bearing on the character of theexhibition, is not out of place in any large building. Likemany inventions, it is extremely simple, and consists of a.covered receptacle containing a considerable quantity ofwater, in which is submerged one or more nests oftelescopically stored fire buckets, which can be instantlywithdrawn full of water and ready for immediate use. Bythis unique system of telescoping the buckets beneathwater ten, twenty, thirty, or more can be stored ina surprisingly small space. Amongst odd and usefulinventions was the patent broaching tap of Messrs. Gabb,Bibra, and Co., which may be likened to a key fitting in alock provided on the barrel, so obviating the waste of the<contents, which unavoidably happens when tte clumsy hammering in of an ordinary tap is adopted. The treat-ment of beer, wine, and other liquors with antiseptics findsample illustration in the exhibition of remarkably finechemical products of Messrs. Boake and Co. Their chiefproduct, and one made by a recently discovered process, is amew antiseptic called by them K.M.S. (kalium meta-sulphite).It is an anhydrous, beautifully crystalline salt, containing57 per cent. of S02’ and has the formula K2SO3, S02. Theadditional molecule of S02 is easily expelled, even,it is stated, by the feeblest acids. It is intendedlargely for the preservation of wine and beer. Someidea of its preserving influence can be gained from the factthat beer brewed in Australia last year, and kept for

’eighteen months, was submitted for tasting at the Exhibi-tion and found to be in perfect potable condition. Theemployment of this salt in the small quantity that is

required would not appear to be harmful. It certainlyseems less objectionable than salicylic acid, while it is apreparation of greater elegance and stability than bisulphiteof lime. " Semper dulcis" is the preparation of J. Boulton<a.ndCo., which we note is advocated as a useful preservative’for milk, butter, fish, soup?, vegetables, and jam?. Men-tion may also be made, while speaking of antiseptics, of thecarbon enamel of Messrs. Crawford and Co., which is intendedfor the cleansing of musty and foul casks ; the bottle-washing machines of Messrs. Clarke Bros. ; the uprightsystem of soaking and cleansing bottles of Mr. T. Hill; andthe ingenious cask-washing and seasoning machines ofMessrs. Thompson and Co. Lastly, of the apparatusexhibited for ventilating, drying, and removing heated orfoul air so often met with in breweries and mineral waterfactories, were the Wing’s disc fan of Messrs. Potter andCo. and the Blackman air propeller.

THE ELECTION OF DIRECT REPRESEN-TATIVES.

A NUMEROUSLY attended meeting of general practi-tioners, convened by the General Practitioners’ Alliance,;vas held at 29, Threadneedle-street, E. C., on the 28th ult.

Dr. J. W. J. Oswald, having been voted to the chair, saidthat no doubt everyone there had received a copy of anaddress from the present direct representatives on theGeneral Medical Council seeking re-election. While it,must be admitted that these three gentlemen had done somegood work, it could not be contended that men in theposition of Sir B. W. Foster and Mr. Wheelhouse couldreally understand the wants of general practitioners, or

advocate their cause with such feelings of sympathy as thoseactually engaged in general practice. For that reason he

was glad to know that Dr. Alderson and Mr. Brown werewilling to come forward to fighb their battle, and he sin-

cerely hoped that they would be well supported by theprofession.The candidates then briefly addressed the meeting,

stating their policy if elected.Dr. Hugh Woods said that, after hearing the addresses of

Dr. Alderson and Mr. Brown, he thought there could be noquestion as to the feeling of the meeting in regard to theircandidature. He felt sure that everyone present would

give them hearty support, and do all they could to securetheir return. It was time that general practitioners madeuse of the power they possessed, and returned as their

representatives men from their own ranks. He wouldpropose : " That this meeting resolves itself into a com-mittee (with power to add to its number) to promote theelection of Dr. Alderson and Mr. George Brown as directrepresentatives on the General Medical Council."Mr. Corbyn said he had great pleasure in seconding Dr.

Woods’ proposition. This was essentially a time whengeneral practitioners should come forward in the mostunited and determined manner to defend their own in-terests. It was no use looking to outsiders to help them.If they wished to gain their point and make their influencefelt in the Medical Parliament, they should not miss thepresent opportunity.The resolution was carried unanimously.Dr. J. W. J. Oswald was appointed chairman, Mr. James

Savage and Dr. Hugh Woods vice-chairmen, and Mr. Camp-bell Boyd secretary of the Election Committee.The names of forty gentlemen having been handed in as

willing to act on the committee, the meeting concluded witha vote of thanks to the chairman.

THE COMMUNICABILITY OF YELLOWFEVER.

AN interesting paper on the Communicability of YellowFever has been published in the "British Guiana MedicalAnnual" by Mr. J. S. Wallbridge, M.R.C.S., medical

inspector of that colony.Mr. Wallbridge contends that the disease is not endemic

there, except so long as we keep up a supply of cases by thefresh importation of the germ, and so long as we providethe favourite habitats in which the germ delights to dwell.Under such circumstances the production of suitable soil inthe person of a susceptible new. comer is like the applicationof fire to a match. The flame bursts forth with fatal force.For some years past strenuous efforts have been made to pre-vent the importation of the disease into Georgetown, and notonly to do this, but also to stamp out the existing germs ofthe disease left as a legacy to us by pre existing cases. Wheresuch efforts have proved unsuccessful they have been repeatedwith renewed and increased energy. What has been theresult ? In 1881, as the result of fresh importation, thedisease raged with epidemic virulence. Since 1881 out-breaks of the disease have occurred from local centres leftby the epidemic of 1881, and no year was free from the dis-ease until 1889. Georgetown has been entirely free from thedisease during the years 1889, 1890, and 1891, up to thepresent time. The three most favourable habitats ofthe yellow fever germ are the bilges of wooden ships, thetidal mud of a tropical iver, and the cesspits sunk in thealluvial soil of a tropical town. As regards the bilges ofwooden ships, his experience led Mr. Wallbridge to the con-clusion that those cargoes which most effectually aid inmaintaining the potential character of the bilges as a homeof the yellow fever germ are coal, timber, and sugar.He has known many instances of the virulent intensity withwhich the disease will manifest itself on board a coal ship.As showing the rapidity with which the disease may becontracted by a susceptible subject he mentions two cases.One case was that of a sailor in the Essequibo, con-

cerning whom the late Dr. Freeman stated, in his report onthe outbreak of 1882, that a visit of only a few minutesto an infected ship was sufficient for the contraction of thedisease, with fatal effects. The other case was that of anoverseer who paid a short visit to the room of an

infected friend in Georgetown, and that visit, which is