LECTURE ON OXYGEN.

Wairarapa Daily Times, Volume IX, Issue 2652, 20 July 1887, Page 2

LECTURE ON OXYGEN.

i:. The • next experiment is an exceedingly . i beautiful one. ' I ignite on n metal pan a ■ i Mo-sulphur, which,- as you observe,: biyns ■ [ with a blue, fambont flame, like hy&ageu. • Upon-pl.unging this into a jar of fotbie bliio light and blow. oxidation' xmage :• to.bright violdt .and rapid combustion. In .this case I can also show you • that •an acid has been formed .by tho union of sulphur with Oxygon by the same means, • This test with bluelitmua, and tho peculiar, suiiocatiiig .sulphurous smelt aresufficient for the idonti- • 'fication of thesoidasßiJphur-dioridei which ' becomes sulphurous acid when absorbed .by water. 5.0.2+H.0.2=H.2,5,3. Another experim(snt<'''-which.\'illußtKtes the mighty ' force of this element is one showing tho fiwi- ■' % with'whioh irbh May be fused and. even • vapourjsdd by it, I.'tako a littlo . iron vrire tipped with burning sulphur andiniiriediately. : - upon, bringing itintoau.atmosphore ' Oxygen,..fusion takcs'place, the moltdn oxide of iron dropping down into the water which 1 protects the ve66el,- • The Samo : .experiinen''''r» can be performed with a watch spring, whift'g when burnt in Oxygen, scintillates in a picturesque manner," Similar experiments pf : on interesting character may be. performed with Strontium Nitrate, .Barium Oxido. and Nitre, ■ .

I will how show you the most brilliant of <•' all tlio effects produced witlutho gas. l ignite- •; a little phosphorus treated in 1 ' the % same w&y :i----as the sulphur of the former experiment, ' need .not point out to yoii the intense ligliV :• • " lat - »t. when burned iu'air—i( is sola- ' ; feyidpnt. But upon being plunged into Oxygen'a light more dazzling than that C of thg'felcetrio arc, and rivalling tho glory of ; ' the'Biin.'is-given out. Tho effect on your eyeswill'bo rather disagreeable for ±tl>% moments, and if it effects you at all anjp& ; .me, bluff,-radj and green patches alteHßelV float boforc.your \ision, 'b.ut this will rajfidlj i:-i wear. off. - 'flic dense white fumes .whlflh eomo off aro a chemical compound of phoa. : ■ phorous and Oxygen called Phosphorus :•• Oxide (P.9Q.C) a highly poisonous substaiice -u which if inhaled would moan instant death; •.'> : Part of this 6jido is absorbed by -the jwat# ; ■ forming ?n acid (phosphorie) which I test V in tho same way as formerly. '. Oxygon may be obtained from wter iby means :of oleotrioity, A pair of wires mv fused into the bottom of a glass tho .axtornalfinds of which aro attaolied plati: ••;••• num foils.. .The trough is partly fiDed witli water,, and over eooh foil i 3 placed an inverted teat'tnba aisoflllod mth water, The oxter- •« nal partAro, connected wiih'tholewiiniils .•/; . of a galvanio battery, aud upon the circuit •'' being oompletod,. minute bubbles , will bp observed to nse in the tost tubes ; in nne^u4 quabtiti&rthatoYor tlio positive electrode ■ containing exactly half as much, as that ■ over the negativo. The gas contained in the ■former I will show to bo Oxygen by. means of . : tho match oxpevimont, while upoii tJjc ; application of a light to tho mouth of (Jig ■ ■other test tube,, a blue tlamowiil atonee-be perceived, showing the presence of Hsfco: gen. This process is known as tb'o lytic decomposition of water, ami' is Sftot " to show that water is composed of two parts by volume of Hydrogen to one of Oxygen. The addition of a fow drops of sulphuric'floid •! to the water.fyjjlitates the procesa by in-; •, 1 ereaping .thlei coiiVluctmiy. : ' Otu - last oxperiment w2lbe'ono'iliußtrating the powerful affinity that ■ subsists", between . Oxygen' and Hydrogen. You. cannot but have observed., the ■ elaborateneaa of tho means employed to separator these two gaßos in water, and tlio comparative slownesa with which they become disengaged under tho action of a strong battery. " To bring them together again in tho form of • water its perhaps one of the'. most simplest operations in the wholo range of Chemistry.. Wo placo in a jar two volumes of Hydrogen .xi to one of Oxygen',' (the proportion, if r® remember, in which thoy exist in water.) v The mere application of a light, or the passing of an electric- spark, is suffiejent to establish chemical combination, a union signalised by a loud explosion. The explosion is duo to the creation of a vacuum and the rushing of the air. The water as formed by this combination may be seen in to fine dew drops on the interior of the jar. -■ Before concluding! may refer to a remarkable substano;, ■ possessing distinctive pro- ' pertiea, called Ozone. This: peculiar whioh is an allotroplc modification . i 8 producod when continuous electricity are passed through Oxygen; and it is to this agenfcy, yiz,, the frequency Of electrical disturbaniea, that ita presence in the atmosphere is attributable. The peculiar odour observed during the working of jin electric machine is duo to the production of Ozone, and if a piece of paper saturated with potassium iodide aad Btarch paste bo held before pointed conductors charged with elsetricity, it will turn'blun, indicating the presence of Ozone. It may also bo produced by ' • suspending a littlo phosphorua- iu a raofat bottlo, and its presence. tested in the Eatsa way, . Ozone is in rcahty a condensed forja of Oxygen, irtd gen'ei'aUy exists in more than . avorage quantities at tho sea sido, hence,'no doubt, tho usual hpaltlifnlness of a tesideate. in such a position.. Ozono ib ono ahdK'hw! times as heavy as Oxygen, or .three-vphimes, / of Oxygen ftondense to two volumes ofOzons. ' , I now draw to ft close, and can only oi» yreßß tho thst-.-thia slight sketch Ijda ' afforded yoii tt.fraotio'n of the pleasure it lias ■ given me in th 6 preparation. If it- has siic-', , v coeded, .even f<ir-'a mb'mont,' in diyetting-ydlir . thoughts frbnl qhannclß" to . the noble faofs.of seienoo'l shall bo well pleaeed. I trust to'yoiir indulgence to OYcrloos many ' faults which were but too apparent, pleading only in exouso that I'had vory short and that muoh blithe: i' v for a diEcourse vr of thia desonptibn' :wW;, " either absent or had to bo improvised. 'My l '---' lecture has had ratEer to adapt itself totuffce [ appliances than the appliancos to the ■ but nevertheless I must compliment' Mr Grundy upon tho admirable discriminatipij he has displayed in 'tlio difficult matter of seleoting instnimento whoro ho had only , i hmited grant at his diepijaal, and tho dolicatfe manipulation so necessary to tho suoceßß-of the : and'iri this place I beg to aooord him my host thanks for the valuable aid he has afforded mo,'.Jboth in tho demonstra,-' tlons and ths necessary preparations', befere'-' the leoture. My thairliS' aVe qJeo due-tujfr Park for the loan of a galvanic battery, .