Puzzles of Modern Science.

New Zealand Tablet, Volume XXX, Issue 23, 5 June 1902, Page 6

Puzzles of Modern Science.

THERE is no softer substance in the woild (fays an exchange) than COtton-wool. and we u»e it for wrapping up all our rao^t trensured and breakable possessions. Tr>at this warm and fluffy wool with nitric acid, and it is ppe^dily turned into guncotti n, o\e of the most terrific explosives knovn to 8 i nee. A pound of <r<iinary gnnpowder, wl-en fired, tak s the hnn )r edth p.vrt <>f a «t cm d to explode. Giino. ttcn goe* iff in on'- fi. tv-thou-audih p.irt ot a second. Guncotton was fiu-t oiM'o\ere- do jcai:< a'jo, and e\ety country was so delighted *nh an exphsive ot such power th t quantities of it were made and stored. But ex lo ion* became distressingly fnq'i»nt. There was one at Stow marker, vvhi h killed 2i pirplp. dreaif ully woui dintr .1, other (>() and m >de the- 1 >wn In. ka-it it had been bocnhar'ie '. I hi.> led to the di-c iv.'iy 1h it guncot on could be mixe^ with water — that is to tin rouyb'y dampi il. and be stored in safe ty. while still reta mug ail its t xplo-ive prop- 1 1 Ih. Torpedoes are to-day charged with tnoi t. ntd gunco'f' n at heavy pressure. Nitrogen is a dull, heavy sort of t;a«. It puts out fi e instantaneou ly, and kills any li\in>_t tinny: plunged into it. Y<*t seventy-fight parta in cue hundred of tue air we bieathc are composed of this jjas. It is the twenty p.-r wt. of <ixygcn which i-< combined with the nitrogen th.it tran-forms it into litegiving, pure, hnd el-i*tie air. Water, on the oti\> r hand puts out fire, and will not nu-tain warm bloodel lite ; \et wa ir contiin u , comparati v^'y speaking, more oxygen than an dues. What makes this c uibi .aMon "-till more p-<.up -<.u lar is th v h^ro/en ga«, winch is 0 tn*»n>-d w i li oxj gen. lof orm water, is m it>e fpo ne,»rl} so deadly B gas a-< nitroir n. It is the litjhce-t of all the na->i v . ai.il *1 1 burn fj>ely in 1 hi* air. Two deadly poisons ■•ppeai pvtry clay upon every table in ihec.vi ied world. Oiie i-< a bluish-whit, 1 ni>ti), which is 80 ( tt-peiatt lv 11 flan.mable that, if sv». iiLow e-d. if would s> t one on fire ill-id-- i':ir o h>T h a jellowi^h tras-. wiieh will faiffoc^e inptmr \ any 1 viiig thini> that, breathes it. The nifal is oroiu 1 . the gas eh orine. Yet, in chemical combination, thet-e two forui common Halt. Charcoal is the purest form in which wt general y Bee the element caibon. Who would fora moment imagine that c\oie than half of the delicate white of an esg is composed of this b -ak ciarcoxl? Yet f>2 parts in every 100 of egg albumen iire etub n, aud f,4 parts in each 100 of the brei.d we tat The>e i-. in l.ict, curt.on m every living thing, whether you Ink-; your own fksL ai.d b'Ood, the pip of an apple, or the skeU ton ot a mouse-. The p< ceil you write with and the diamond in your scarfpin are composed of the s-vme element. The keen steel of a razor blade depends on carbon lor its hardness. Lees than on** part ot carbon is there to the i.in- ty-nine parts of iion ; yet without it, the blade which w.ll cut a 1 air would be no better than a barrel hoc p. On the oth r hand, il more than that tiny proportion of earb<>n v\e>e mixed with the iron, it would be Bteel no linger, but mere brittle cast or pig iron. Gold, when ahsolute'y pure, is so t-oit that it can Le dtnUd w ith the finger-nail. Add 01 c pound of copper t) twenty of gold, and the resulting mixture i« almost as h,.rd as copper itself. Numbers of metallic alloy c* s« em aliiio-t nw'r<>cle s, to diffeient me ibf y from the materials which havv gone to coa.p >(-c 1 lam. Bias-s is extremely unlike either the cupper »t zme w hn li in,.t c it ; but the most curious thing about brass is that a veij little U\.d added to it v\ lllicauseit in appearance to precuely re-ien.ble gold. Why duil, grty lead should have this effect is one ot t l c irai \ imu'it pmi! meiallurgy. A little nickle Bdded to Bt> el will n ake a mixtur harder than either of its con-j-tituentF. Phosphorus, the softest of a'l the metals, and one of thfrlightest, gives enormous strength and e : e .sity to bronze, making it mor< t uitable than even steel for certain purposed ; i*nd this hat u.ight be indefinitely extended.