Science.

Wairarapa Standard, Volume XX, Issue 2055, 15 April 1887, Page 2 (Supplement)

Science.

An account is given l>y a Uussian ci:-■ i!iit cf sumo experiments made by him with a view to ascertaining what mixtures cf.ii'Us will give in sun,iglii the same effort u;>.>n tile eye that is produced by various kn-.'.vn colors as viewed by artifi-inl 1 elit. A special form of photometer was i>r I. in which one half of the field of vision i- -ipie 1 by the piece of colored paper i.laminated by the artificial light, while the “ib-.-r liaif is taken up by a card placed upon the table and exposed to daylight. Upon the surface of this can! the colors arc mixed until the general effect equals the tint of the oilier, and the two halves of the screen appear of the same color. Thus, to give to white paper the appearance which it has under the rays of a petroleum iamp.it is ne- < s ary to color it orange, if the petroleum light is very bright, Papers colored reddish orange an i vermillion become so intense in lamplight that it is impossible to imitate them by means of oil colors, and violet pigments take the aspect of reddish brown, not in the least resembling the true color. The mixture of pigments thus obtained, looked at apart from the light of the sun, arc very far from producing to the eye the same sensaiioiis as with the light of a lamp. In fact, the sensitiveness of the eye for various eulors of tiic spectrum changes when this mean is accustomed to the yellowish light of petroleum.

Gapes in Fowls.— The fact that the disease known as gapes in poultry is produced by a parasitic worm (Si/iti/iium* tnn fiinli*), which infests the trachea of the birds, was s 'ttic I Jong ago. and for most of our recent kn.iwlcdgo of the worm and the disease we ai i indebted to the prize essay of Bicrrc Meg nin. According to this author, the mature worms and their eggs are coughed • i'll of the throat of the infested fowl, and th" di-casc is spread by its associates picking th in up ail along with their food or by it liking water in which the eggs may have hatched into larva'. No suggestion is allowed of any intermediate host. Mr. If. I). Walker, in an apparently carefully prepared paper on this subject (Bulletin Buffalo Society Natural Sciences, Ism!) details many experiments which he lias tried, and several of them point very strongly to the conclusion that the earth worm may. in many caccs, play a part in the distribution of the pest. The embryos have been found living' in the earth worm at all seasons of the year, and eaith worm* from infested localities, when fed to eliieki ns. almost invariably produce the di-ea-c. Dr. Walker lias also produced tii" disea-e in robins, and claims to have found the embryo of the lung worm of carivs ( ,S‘noq/!//«.,■ uin'rurus) iu the earth w--no.

The plan has been proposed to manufacture rolled and polished shafting by a new method. The round bar of metal delivered from an ordinary rolling mill, and while at a cherry h-at. is subjected to the action of a group of tapering condensed rolls, which act peripherally and progressively upon the bar while the latter is rotating. After the bar Ins .• ■Tr these rolls, and when it is substantially fr- e from 'neat, it, is introduced into a iii-,-dravying machine fur suitable construe* t;-ii. By this double manipulation the sure fa--.- of the metal is first worked in one direction for producing a eonden-ed scalclcss s-.n tai.v, and then in a direction substantially at rigid augi's with Cue first for producing f:e llnisli. The .-uaft made according to (Ids m-.ih-iiis said u. be of uniform diameter, an-i to have its surface metal condensed, hardened, mid fr -e from pits and cheeks.

The Delicacy of the Sense of Smell.— To ■ delicacy ..f tire -ense of -m,-li in tlie dog rii" -hint, ant insects i- well recognized. Man is not greatly gifted with the olfactory s an- compared with these; but, if we may place v--dance - u the experiments of I’rof r \ ali-nline, the delicacy is fairly great even in human beings, if vve can sniff a (■•nth of a pint of air containing bromine in lire proportion of a thirty-thousandth of a nuliignumn,-. or the same quantity of air impregnated with the two-mißionth of a Milligramme of sulphuretted hydrogen, we cannot mathematically have ground of comp aim against mir olfactory sense. Still less can this be the c.a-e if vve can, as seems i.io-ly. detect the giiu-millionth of a milligiamine of s-aiptuu-ette 1 alcohol or mercap tun.

A Standard Metronome. —M. Saint. • s *‘as sugg-. -te It"! he French Academy oi > i-iu-es t a;*i it should undertake the, work -■i providing a standard or normal rnctron an ■ for tbe benefit of musicians and musical ait. Ihe Academy has already rendered an important .service to music by the establishment of the normal diapason, and as the metronomes now employed are not standard-ize-1 or uniform it would be an additional service if the Academy also constructed and i-sm -l a standard instrument, while requiring that those in use should lie made to agree with it. The metronome was invented at the end of last century by Stocckcl and perfected by Maeizel ; ami though univer--ally employed it is tiv no means well icmilatvd.

Damming Back. Mr. Tiotjens, of Ma- mui. (iermany. lias recently patented a v.-ry ui-’t ni oils method of (lamming back the il ivv ot water in shafts by tire- application of la-- w..-11-kn..wu fa-t that c.-iiaiu -alls incr- their v-'innie very marcriallv by the ao- nbing of water of crystallization In bi- leinng. To acc.mip'.i-!, n,,.. | :v i.,. s ■ ;;!icr cal.-im-i - ,!;i anhydrous alum, ki.-s----r:; -.j-i- i-xy.-hl-.r.'l • of magnesium, mixes uum into a pa-o . and r In-n inn to dial .-lv in- ■ -ci- tn.-m tlir.-ngli a -uita’P y an-augcl pip,, nit . t:.e lu-ii; - tin- nigh which the wainAs this pa-i-- hardens, ii eiioi.-gii to till a!] th,. iutel-tio-s of the rock an '• i -U-lei it th 'roughly water-tight.

Flus-Dust Bricks-~-An analy-isof many t 1 :- i.-atid ton- of Jlac-diist showed it- (- nn. po-itf-u t" contain the f-.llovving • Silver. fl-’TI to :;f minces per 101 l ; 101 l I’rnlllt'll o :;i- i, r cent.: gol-1, from trace p. ‘ i.uncc P-. I -n: /ate-, fr nn to percent.; ars--nic. jII mtr e-> to I; |i r cent..- iron, from 11 to go in r e--nt. Itn- dust is Worked with water ati I -i ik-'i line-, is mixed and Intel-: into | "U--ks in a pug-mill, similar to Um-e in use I at I'-, - brick-yard. The place in which the u .-.k -done is sii; rounded by a brick wall. # p- I'l- vi ut the iiiierfer.-ncc of the wind-, as "-ie material is wry light. The dust-bricks arc sun-dried and again fed into the large furnace-.

In order to render paper as tough as wool or leather, a plan has been devised which, it is said. effeeUiallyaceompiishe.stlie ptupose, namely, by combining chloride of /:ne with the pulp in the course of manufacture. It has been found that the greater the degree of concentration of the zinc solution the greater will be the toughness of the paper, and that it is thus serviceable for making boxes, combs, fee.

Infant Weight— Tile Journal I.Won•Crnr!ion states that an infant 10-es from three to six minces in weight daring the first foorl i-ix days after birth; by the seventh ■ lay i; duoiM have regained its birth-weight; to-m ihai lo Hi ■ fifth month it ought to gain ab V live ounivs per Wee!;, or about six dram- a day : alter the tilth month it might t ■ have do tob.'d its lurth-weight. and in sixteen month- guadrupled it. Petroleum Engines for TorpedoBoats- —Ah Au-i: j;t:i .!• rli i'-inn nrimctl Mare.,.- j- -applying ih- ii .rinan navy wiih a n ",vly ill v. ill" 1 p-trol-uni engine for torI';" 1 " '' iru '- 1 h ' ' name i-.-et in motion by •■I-etro-magn.f.-io, and is more powerful than a -t« am engine ( .f the sai,,.. size. It inot liable loexplu-ion.