SCIENCE NOTES.

Otago Witness, Issue 2520, 2 July 1902, Page 76

SCIENCE NOTES.

— Professor F. W. Tunnicliffe. in. the >ourse of an interesting prticle, remarks that »Jvc Gertaan Government has already \otcd j, sum of 50,00.0 marks towards the endowment of investigation 1 ! into the nature of cancer. We aro only now beginning to *ivak< n to the necessity of providing for the parrying on <f sy=tc-natic v.oik of the kind. iVere ]* a caiicri commission in connection niththo flarv.-ird M^d'cil School 111 Ainenca, and Buffalo al'n pu^cs;^ a !St Uc- laborru.-r} for eanrer imc ~u^muop In Aiiun.ca, so fai. the Buffalo linc^tiratur ~ 11 c'llll 10 t'ao 1 cia ! that oancer is an inf'TUous ailnl' iit. but 111 wbat degree, or whether duoctly or .nch rectly contagicu-. are piu n not >tt c!cF. Tiitely ascertained Dr Tunmchtfe. m his jtrtiele, remarks t*iat. while tuberculosis ca'i readily be conveyed from animal to an.mal, ''this certainly is not the case with cancer."" ilen.ee axie&a ono gi the diffi > *"^-' fltt oi laves-

tigaUon— that of ascertaining the infretivity of cancer, and the true nature of the presumed gcims or organisms which arc supposed to bo capable of conveying the disease. \\ lion we sp<^ak of "con-sumption houses" we imply dwellings noted for the occurrence of cases of the disease in family after family inhabiting them. Thfre h no difficulty in explaining such events. The surroundings of the houses are such as to favour the development of the microbes of the di*ea&e, and the germs left in the hou«e from previous casei affect members of each succeeding family of tenant?. For these reasons disinfection of all houses which harbourTonsumptives should be made- imperative But in tlie case of eanrer, it is curious to ob?ene, we meet with analogous circumstances. The exioten.ee of "cancer hotisos" has long been known to medical men, and years ago was duly noted in the pages of professional journal. Dr Tunnicliffe says that the existence of dwellings notorious for the prc\alenco therein of cancer cases rest" upon \fry strong evidence. If tin* be- so, the fart points to a very material something as the cau=c of the disease : a something which, like the mioiobo of tuberculosis, must be derived from previous cases of the ailment, and must remain latent- in the domiciles, awakening up into vitality when the circumstances are favourable

, — Our present state of ei\ihsation has of necessity resulted in an annual increase' 111 the amount of capital borrowed by man from the store of energy accumulated by cur earth in byjroao- tini€i-, and the diversion of this capital to u= o> foi which the world's annual income* of -olai energy wai> formerly deemed inadequate An instance of this tendency is afforded by the experiments of Dr Selim Lemstrom, of DeKingfors, on the I'&o of electricity in stimulating the growth of cereals, vegetables, and other pants. A German translation of Dr Lcmstrom's paper has now been issued by Dr Otto Pnng^heim. The investigation seems to have been suggested in the first lnstam c by an attempt to connect the luxuriant growth of phint3 in high latitudes with the influence of electric currents arer * Ued with the Aurora Borealis. The experiments showed that for plants growing on arable land of medium quality an increase of 45 per c>nt. in tho crops h obtainable; but the. better the field is ploughed and eared for the greater v. ill be the increase. On poor c oil the effect is trifling. Certain plant", «-ucli :v peas, cabbages, and turnips, only lend t''emsehc= to electrical treatment after being watered. Tt is. however, iniurious to most, if not all. pants to submit th"m to tb<» mfhifrrc of electricity in hot 3iinshine. In t'lp introducj tion Dr Pringsheim makes seme estimate of 'the cost of applying the method to agricultural purpo&es, and arrr <-.-* at the coik lu-ion that it can be marie to r.av. A further MUjpsiion is that we ha\p hero an "viil.iuation of the necd'e =hap«»d K-.'tvr- of cmiferous ; lants. which are well adapted to fr.'-ilitaio the pa"-a^r> of electricity. r i". 111 c mn.on parlance, "attract elp-ctru ity — Xa'Mre I — Turh'ne madi'nerv is ncretif'ni" npid'y 1 in Air erica for the produorion of rli-ctri^ 1 light and nowcr The Wcunehoi" c C< 11 panv. whie'i hss eppurpcl the i>vrnt na!'!* for tie P: r-ons turbine in tl c T"i>itc-d Sra'o?. I i-. r.r>w building eisjlit turbine-*, inii^iiig fiom Hi to 2500 horso-power. BajtionL

Connecticut, possesses an electric light and power plant with a turbine of 2500 horse-power, which has Deen working for about a year, and is, according to the Scientific American, "the largest turbine, and probably the most economical steam engine, in the world." This amount of power will be very considerably exceeded by the machines for the District railway. The Admiralty have ordered both third-class cruisers and destroyers with reciprocating engines and with turbines, so that it will be possible to compare similar vessels of the old and the new type. Three large steam yachts have been ordered in this country to be equipped with turbine engines, and the owner of one of the iargest yachts ever built in the United States has. at the eleventh hour, requested that the plans be held in abeyance until the performances of the new British yachts are made known.

— What, one wonders, will be the mileage of electric tram and railway lines in Great Britain at the end of the century? Smaller than at present, if Mr Wells's "anticipation" of a new era, in which the smooth road will take the place of the rail, be realised. But the figures of the end of the first official year of the new century, which have just been issued by the Board of Trade, are not i.nimposing. They show a total open mileage of 1305 miles, while the pasrengrc-rs during the year numbered 1,198,226,758. The number of undertakings had then reached 213, of which 99, extending to 689 miles, were tinder local authority, and 114, of 615 miles, weie in the hands of companies A suggestive po'nt in these and cognate returns is the decreasing number of tram horse? Whereas in three years the number of electric tramears has advanced from 5335. or 34 per cent., the number of horses has decreased by 4353, or about 11 per cent, of tho whole number employed.— -Morning Popt.

— In some of the old text-books of physics may be found an account of certain experiments winch took place half a century a?o on the Lake of Geneva, the object being to ascertain the rate at which »ound travelled through water. Two boats v ere employed, separated by about one milo, and a sub merged bell depending from one was clearly heard by a <-irnple form of resonator sunk by the other boat. We are reminded of these old experiments by some trials of submarine fog gignals which took place in Boston Harbour last year, and which are about to be repeated on a more extended fcale on the English const. Preparation? aro now being made, of" the Egg Rock, Lynn, to nifpend from a b'iov in 50ft of water p powerful bell, capable of being struck bj an electrically worked hammer from a station on shore. It is expected that the sound of thi-. bell v. ill be audible to anyone on board ship fiom three to five miles distant, provided that he places his «-ar against a rod h<=ld in contact with the vessel's hull. It is ewdent that if this theory be correct a va'uable method of guarding a ship from too near an appioach to daugerous shoie^ has been hit upon The system also offeib a method of communication between passing ships and bctwen ?hip and shore ; for, in connection with a signal code, the submerged bell would offer a ready means of spelling out any messages desired. — Carbon bisulphide ib rarely heard of outtide the workshop or the laboratory : yet few chemical products have more varied uses --all of which, however, depend on the fact that the substance is a powerful solvent for many organic substances, and so readily volatile, that it may easily be separated from the- matters dissolved in it. As it readily dissolves fatrs airl oils, it serves for the extraction of fat from bones destined to conversion into fiiimal charcoal, al-o for the complete extraction of palm, olive, and other oils from their vegetable sources. It has been used foi cleansing wool, for recovering oils and fats from refinins: media, and for improving the metallic surfaces obtained in electroplating. Most important of all is its use. in the indiarubber industry, in which it serves both as a solvent and for "vulcanising" the rubber. The latter is done by dissolving rubber and suilphur together in the bisulphide, which being then evaporated off leaves vulcanised rubber behind. Hitherto the useful application of this substance has been hampered by difficulties met with in preparing it. The old plan was to i.ass sulphur vapour up through a tower filled with charcoal, at a red heat The sub ptances combine directly to form bisulphide. The disadvantage of the method is the smalll.es.s of the yield compared with the amount of fuel expended. It is now found to be possible to produce the bisiilnhide quickly a'vl profitably in an electric furnace. The furnrce i-, a of iron tower lined with firebrick : four insulated carbons arranged at tho bottom of the furnace convey t he current, and the materials —a mixture of cjke and sulphur — are continuously fed down towards them by their own weight The coke falls on to the top of the carbons, while the sulphur is melted before reaching them, and flows down to the bottom of the furnace, and up to the carbons The bisulp'.iiue vapours are carried off by a pipo near the top of the>furnace, and condensed One such furnace can produce 80001b pfr clay, and with greater power thr> daily yield is expected to rise to nearly 20 ton?

—In a r°ceut number of the Electrical Re\iew. Profes-or Trowbridt;e dcbc-ribc<i some, interesting experiments which he made with the electric spark in water. He states that it is po«-Fiblo to produce a brilliant di-chnrpn 111 carefully dL-'illed water, provided a ln^h electro-motive force is employed. He l.as found 500,000 volts with a lart;p capacity suitable for the purpose of spectrum analysis. Tl>e electrode-^ were platinum wires inserted in long gl?ss tube' and placed nn inch apart. It was npce=sary to have an additional sr-ark gap outside, the liquid. Profe-sor Trowbridijo states that the light of the hpark produced under water is of brilliant whiteness, rescrnbling that of an enclosed uxc fa nip — Tho original carbon filament of tho electrical "nlmv" lamp is gning place to othcis — notably i-i the Norn-t lamp, which has a filament < r - rare ">--h. siicli as aie

d in tho mantles cf tho incaaidc scent , gas lamp- In •■- n» w glow hmp the fila- | mrnt is of carbon with Illinium, one of fl;e=e lare earth--, and the ula-s bulb is bifurcated to present the ln»s of f-lcc-tric energy between the el<ctrode<- entrrnifr tbe p-lab? to connect with the- filnmrn*-. Tt is , c'aimpd foi tins lamp tint it «a\i-5 from ; 40 to 50 per crnt. in tlif> pi ice of the I light to the cor «urn or. and that it sjiws more light wi'li le = 3 lieat than the ordinary 1 (irhrn glow limp The bulb is eomnnia tmlv cool after the lairu ha-5 burned for ' a wl/ile day. and fho gla-^ was clear— that 1- to *nv. not blnckr-ned by the depo-it of c.ivbon particles m-ide. after a tr'al of | t"''jO liour* The lamn ii al-o «aid to be fitt<! for nirfnt- of o\ ci 200 volts than tho f in pi'v-rai f= c. - \ nri">i i,i fii.'Pr's "Nfrcazine noint-, out that tiic 'VoliPrT,'' the extremely sensj- i U\e> infiti anient ol wlrele*a teleuraj)hy J or al

modification of it, suited to current electricity, may be found applicable to cable working, and, if so, a great increase in the speed of signalling may follow. The weaker the current required to work the receiving instrument the higher may be the working speed. When the first Atlantic cable was laid the ordinary Morse telegraph relays were employed, and with them the rate of sending was only two or three words a minute. It looked, indeed, for a while as if the cable could not possibly transmit a sufficient number of words to pay. Lord Kelvin's "recorder" and "mirror" instruments soon dispelled the fear, and the sending speed was raised all at once to three and twenty words per minute. The coherer is many times more sensitive than the present receivers, and there is doubtless an analogous instrument waiting to be discovered for cable purposes.