Professor Black's Lectures.

Lake Wakatip Mail, Issue 1516, 22 January 1886, Page 5

Professor Black's Lectures.

Profeasor J G. BI»Lk, of the OUco University, who ia «u:ftiii on a visit to this district, arrived at Qtteeu«t<>un on Satmday night, hut, ow inc. t> his detention at the Thames goldflelds. ami the many other places at which he has lectured, or intends to lecturi;, he found it im|MN«ihle t> devote more thin two days here iu the advancement of knowledge useful to the miner. Tic- snhj-cta of the lectures on each night were Gold— its origin, it* formation in quartz reefs, its distribution, our alluvial drifts, etc, and other matters relating to the same. Notwithstanding the very luief pu»hc notice the l-c*ures (which »erc ilelivered in the public ■chool-mom on Monday and Tuesday evenings) were well attended l>y an attentive and intellig»nt audience—the nxmher on the first tiLht l«eimr over 100 Crsons. Some two or three hours lief ore the :ture on each evening. Dr B!a k exhibited to a cliss fif students the various t>s»* for a jreat ranety of o>e*. For this pur|H«e he, as a rule, nealt with the stone* ami ore* which contain the Oiet.il* puKerised them, dissolved them m acids, then filtered t ! >e Solution*, and added the »arioiis chemical solutions which constitute the tests. In this manner he dealt with the ores of numerous minerals, mich as silver, lead, mercury, antimonv, coptier, k'ohi. avheehte, etc., etc., tins molu* Ofrnwli in many cas«s being studiously noted hy those present.

On Monday evening Professor Bla.-k commenced his lecture by drawing attention to the i nportant part that carhomc acid pays in form in,' and inodifii i.' the crust of the eirth. He p unt-d ut the S' ur -es of tiie acid in the breathing of animals, the burning of fires, the deciv or oxidation of plant and animsl substance*, and esji-cially in the action of internal he it on misses of limestone near the roots of the volcanoes. Cat home a>id bom the-e •onr.-es, carried atom; t■ \ w iter under ground and travelling towards crevic s previously formed, broke up the hi i i ares and li'-eiated sili-ic a* il. Tins •ilicie avid dissolved iu the fravellou water and found its way into the i-re»ices, where it is left as a deposit of ipiattz as the water dried up or was a!>*>i-!ie I. In this way roinv reefs hue doubtless been fornied, while others have resulted from the deposition of j>ai t of tiie silicic acid on tin- paths in whi h it trtvrls. forming stringers or leaders of quart/, and perhaps, in some ca-es, reefs of considerable size. (In illustration of this part of the lecture, silicic acid in a gelatinous state was mule on th- lecture taMe hy passing flu utile of silicon gas through a liodv of cold water in a tall cylin lei ) The leirued lectmer then went on to explain how g»ild came into the reefs. Chlorine was male ot. the lecture table by lieatini; blaek oxide of m inganete with mm iatie acid. The gvs wis led into a kdiss cylinder, into which powdere I metal'i- antimony and metallic arsenic were afterwards thrown in the immediate form it on of white cloudy vapor and an intensely white flu'i of b.'ht. Tiie experiment was nude to illustrate the L'reat piwer of chlonue. in couibiuiug with the in-tals. In toe sam way it was explained •.•h'onne wou'd •oinljine wit i coM Chlorine, it was explain il. would l>e produced underground by the action of air or oxygen on sulphur, an 1 the ■nhaepieiit i«tmn of the sulphuric a-id thus produced on hln'k oxd.- of nim.anese and the s dt iu the rocks. The chlorine th is made in travelling through th- r- ks would dissolve any toll ill y contained, and in -unpin-Non with water w nil carry it in? i the re-fs. w-'ien it would is; tin own down by sulphi'e of iron, snlpliunms a-id, or by many oilier substances whi h find their way into the crevice*.

o*mg to the large nnmWr of tests male on Tuesday eveain.'. it wis la'e before P of. Blu. k wssenaMed to commence Ins lecture. The learned gentleman apolo.:is»-d for tu- abort time at his disposal. *"d •it I he Would eousetpucntl v only !<*■ enao'ed to 9|«*ak of a b-w important m .tt-rs. He referred to the v due of nitric acid. sh wed h >w to mike it. and vartom trsts to its purity ; the way t.. dean c»pper platen used in the collection of gold in quirtz c'Hhn.', etc H-- aUo 9|«ike of .1 odium amalgam, in I the wav to preserve it, uaineli, in a vessel under kerosene, or naptha. or in a cloaelysealed bottle. After «ev~iai tests the learn d lecturer then yavc an in ten-stum dis.-onrse 00 alluvial formation of gold. He referred to tiie commonly accepted theory that all gold found in alluvial drifts was (barring the wear to winch it vn subject in Iwing carried along streams with other matter, just as it had co ne from ipiartz reefs broken down from the mountain*. He expie«*eil a belief th it siluh were not wholly the the facts of the cue, but that the bits of _'o|d brought ilown from the reefs grew bigger—that the particles of g-1 I in solution in fanning water formed on to and constituted an addition to these bit-t, which foimed a nU'l-us. Gold would, in his opinion, grow round a nucleus which had no gold at first. This was a view which was taken by nearly all great chemists and many scientific men of the present day, and it was believed in by Professor Ulrica. Dr Black ad>an ed eeveral arguments in support of this view, aid also cited some iucontestible proofs.

At the conclusion of toe address Dr Blaek said, in reply to Mr Hot op, that he thought it would Iw ad visa Me tor the people of tins district to Win a class, in order to rai*»- stit>srripfions for tlie pun hose of chemicals for a labor;.tory, and to establish a bran hof a school of mines. On the \Y»*st f'o.»st, at the Th ime«. and ot'irr p'aces. surh had be»-n don*' i» i>r>ler to g-t a subsidy frmn (jovcriinicnt, Dr Black »lso promised to deliver a lecture on agricultural ch'-mistry. Resolved that Messrs R»-ld, Rid red Geisow, Warren and Hotop be appointed a committee to <*arrv out the ne fssarv steja for tlie o'>j.cts ahovementioned

A h-artv »ote of thanks was accorded tiie Icirmd lec'nrr-r. The usual cooiphnieut to th-.- cLairuiau (Mr Reul) concluded the pro- efdings.