June 8, 191 1] 



NATURE 



5^5 



ticulum of the enamel-organ. (4) The abundant evidence 

 ui blood-vessels within the enamel-organ, thus confirming 

 the observations of Poulton and Howes in the rodents. 

 The opposite opinion is usually held. (5) Some slight 

 . idence in support of the fusion of enamel-organs. Such 

 ision has been recorded in the fishes and reptiles, but not 

 iherto in mammals. — Rev. A. Miles Moss : The 

 :)hingida; of Peru, based on studies of Lepidoptera, with 

 special reference to the larvae, made during a rhre>^ years' 

 residence at Lima. — Dr. R. Broom : The sirurtur.- of the 

 skull of cynodont reptiles. The author, afur a >tud\ of 

 all the available material contained in the Britih-h and 

 South .African museums, gave a detailed comparative 

 account, illustrated by a series of Hgiin->;, of the morpho- 

 logy of the skull in the chief gimra of the Cynodontia, 

 including Bauria, Xythosaurus, C yiiognatluis, Trirachodon, 

 Gomphognathus, Diademodon, Sesamodon, and Mrlinodon. 

 He also discussed in some detail cfrrniii pi'dilinriiics of the 

 mammalian skull, apparently d-riv-d iVoni .1 ex nodont 

 ancestor. — Dr. C. \\'. Andrews : A new s]>ciir-, of Dino- 

 the^ium from British East .Africa (see p. 457). 



Geological Society, May 24.— Prof. W. W. Watts, F.R.S., 

 president, in th^ chair. — R. J. Lechmere Guppy : The 

 geology of Antigua and other West Indian islands, with 

 reffniicc to thi' physical history of the Caribbean region. 

 After ninirin:; the work of former observers on the geology 

 of .\iitigua, the author gives a brief description of the 

 formations of that island, showing that it is divided into 

 three principal regions :— (i) the volcanic (or igneous) 

 region; (2) the central plain; and (3) the calcareou^ fornia- 

 tion, the first-named being, according to previous authors, 

 the old. -I, ;is it is i)re-Tfrtiary, and the others following 

 in >ii( i-.-^ion. Th.' calcareous formation, hitherto con- 

 sidered the newest, contains fossils, of wliich thr in(»t 

 remarkable is a species of Orbitoides. Aftir a dis. ii->ioii 

 of these formations, and especially of the cvidcno' for tin- 

 so-calird ■• Oligocene " age of the calcarcou., formation, 

 the conckwioii is reached that this formation is thr oldoi, 

 not rh.' Noimorst, and is probably Eocene or oldr. The 

 island wa- raixd above sea-level by the developmi-iii of the 

 great .\ntillian dislocation, which is described, and dividrs 

 each of the islands of Guadeloupe and Antigua into two 

 parts, of which the eastern is calcareous and tin- \v --t, rn 

 volcanic. In .\ntigua the central plain intervenes hftwien 

 the two parts, while in Guadeloupe thev are onlv sip.natrd 

 by a narrow channel. |n -.upport of lliis proposition, (he 

 ph\>i(al fealun-., of .\ntigua are rliscussrd, and it is shown 

 that the island has not he,,) -.iihni.M-e,,,! ^i„ee the volcanic 

 peri<ifl. 



Institution of Mining and Metallurgy, May 31. — Mr. 



11. Livingstone Sulman, president, in the chair. — C. O. 



Schmitt 



The main 

 stam|) tuhe 

 been adflui 

 ment that, 

 abandoned 

 than ill- 



I'ulLire economies in Rand reduction plants. 

 ide.i pernie.iting this |>ai)i-r i^ .1 defence of the 

 -mill ( (Muhination, against u-hicli arguments have 

 ed li\ oilief aulh()ritie>, with ilie further argu- 

 if eiili,-;- eoniponent of ihis comliinalion is 

 in the fuiuie, ii will he ih,. ^^lavitN si.ain]) r.ather 



capai)le . 

 Naturalh 



he-mill that will i> 



ji'odut ing a liner p 



cliief point of thi^ 



cussion on a matter ronierning 



tinct schools of thought. I Iv . 



duction that, if workin:; i-,,-, 



figure, the limit ol ■• ■ 



aiJprosinialely a! a \. ! 



of time that can \><- 



depth at which |)rotii 



the period of life (,| ; 



working cosl > and r. 



factor a-, regaids wli: 



\Mial is known a- :1 



on the Rand with the 



gave satisfactorN i 



' repi; 

 Oduci 



paper 

 which 



d I. 



iher. 

 )oini- 



;i uiachini 



l-e,lnce,l 



]iriinii>ti 

 .U'e I w, 



)nl Ml inln 



will 



i|Uentl\' 



Ih. 



e \i.-W 



uli^ w 



proceeds to ,anal\^. tin 

 the sorting an^l '■■ ■ ■'•■'"' 

 plant, and li 

 and exhau^ii', 

 scale, ih.. eriici.ii 

 material of a \'u\' 

 will !).• an im|)or' 



\'>. 2 1"!. 



mil 



.lish.d r. 



III. 



costs to meet increased expenditure necessitated by seek- 

 ing ore at depth. A considerable amount of data has been 

 collected for this purpose, much of it in the form of tabular 

 matter and diagrams of typical flow sheets in modern 

 practice, with the view of showing that double-stage crush- 

 ing is a certain means of effecting marked economies in 

 operating^ costs and securing better extraction.— .\. C. 

 Hoare : The roasting of complex ores in gold assaying. 

 Opinion is divided as to the advisability of roasting before 

 fusion when assaying complex gold ores, and though in 

 consequence of experiments it is now established that there 

 is no loss of gold by volatilisation when telluride gold ores 

 are roasted, the volatilisation losses, if any, met with in 

 roasting other complex ores have not been d.linit.-h . -tab- 

 lished. The author therefore undertook this inx^igation 

 with respect to sulphide ores containing iron p\rii.N, which 

 after careful assay had a base sulphide, such as zinc blende, 

 stibnite, cinnabar, or mispickel, added to them, so that 

 the influence of the sulphide on the roasting could be deter- 

 mined by subsequent assay. The results of these experi- 

 ments showed that there was no loss of gold in roasting 

 low-grade ores containing zinc blende or antimony, but that 

 there is a loss when the ores contain aisenic. cinnabar, or 

 mispickel. — G. M. Austin : A prospei tor's ni.ihod of gold 

 assay. In this paper the author details the outfit necessary 

 for c.irryine out assays in a remote district without the 

 ne.'d of taking an elaborate equipment, .and he furthermore 

 gives the results of a number of i.'sis mad- with th.' view 

 of determining the degr.'e of .iccuracy altainahl.- In means 

 of .a coinp.ai'ativ.'ly simple ouilii, u-ing on.' of iwo methods 

 ol a--a\ ol which h,- gi\.'s full p.ar' icular-. 



.Mancui;sii-.k. 

 Literary and Philosophical Society, May 9.— Prof. 



V. ]■'.. \\'eiss, president, in th.^ ch.air. I-aaiest !•". Langre : 

 Soin.' remarkable steel crvsiaK, coupl..! wiili some notes 

 on the crystallisation of th.' ii-.>n-( aihon .illo\^. The 

 crystals were discovered by Colon. 1 1. !•;. \'i( k.rs, C".B., 

 in the cavity of the rising h.'ad of a l.n-^;.- st..! ■--'-'.<, 

 and were preserved by him in \ i. w of i!i.' know 

 of the occurrence of such a ni.i- ■! ii.rhiily .1 

 steel " pine-tree " crystals, ;i^ ■ lline structur.s ol 



steel are usually ;ill()trinior|)!, ! of idi(>mor])hic, 



that is to say, th.'ir geom.-lrical Immhv do nnl, .'xcpi in 

 very unusual circunivianc--. loii-.'^pond wi'.li iheii- inii'inal 



crystalline s_\inni.i!'. \ .-'■.:.., '. a ih.' c.i\;:\' w.is 



exhibited which sh.. 1 wiih inianiidal 



apices of the cr'.-i.c .;L|uid m.'ial, .and 



m.a~->.'s of ci"\"sIaN up lo 14 01 1 j; inch-'^ in l.^ngih ]).aul.int 

 from ill.- upp. |- poilion of ih.- ca\it\. \y']'-r'- ih.'v had 

 slowl\ foiin.il and .'long.it.-d \>. ' " '-.h 



reni.arkahly lilll.' inierha. nc.' 11- 



stances of size of casting and .,.- ,m^ ::■ .n ; 



of cooling. Referenc was ni.ide to th.' loluin 

 of steel <'astine-. .mil ingot-, ,1^ . .ist 

 althoi:. ■ ■• - -,lu>w -ucl 



coliini; I . !'■ 'xp. ■rim. Ill - 



had -ihiwn ilia; llv inl.'i'ioi- ol " 

 wari.ihh' sniiM>lh, and ih.il ordinariK 

 in snmolh p.ar.dl.d l.r - ■■-■■■■■ ,-■ 

 growth^ tow.ir.U ill 

 i-r\'MaU had ;:- \- 1 h. 

 nieni . 

 h.-.-n ■. 



>f ih.' iio^ .u.d 

 ' >^nioiid .ami ( 



i.iliorioii'~n."-s .iiiii lUL^-nu ;\. in- 

 internal s\nini.tr\' ot ih.- .r\>.Iallin. 

 sl.'.ds h^■ ' I.,n:.ri. OM-. -h,.w oc :h 



ml 10 • 

 I --tron-ix- 

 Muh-r •■■' 



H ickson, 



hin ])i'op.'|- liiniK. I Ii.' ,iul hor i' ■ In 



