TAPPING THE AIR.

Dominion, Volume 1, Issue 169, 10 April 1908, Page 4

TAPPING THE AIR.

;"r/ r i% ,a:y ' ■■ NITROGEN FOR' THE FARMERS,

!VAST ZEALAMD:INDUSTRY FORESHADOWED.

: (■• The world's food supply rand the fixation of. ' atmosplicrlc nitrogen: New Zealandjsire-: Ifltiop to the problom. (By Geo M. Thomson, FL S, F.C S ) 1 ' ,'lt;is) just jtblU ■..- Crookos, :in:his'-address".as.\: President, of the i.\'-'British.) Association,' drew;'the attention' of t-ta v- i.■ civilised world to' thp-question'of. food-supply. ;& '4';^i: ; tho x^p,ujaj;ion.^of: the! )V k; ,-) : ,; >:)worki')is s6;rapidly ;tliai;;tlw;j\ipply :^-'=t ; f';iv!:-^iV/pf-„^h«tywill i rsjboK'not' ;^ v it.' And .though■ Msv Konly! to. ■■ ~4'twhcati: it is -applicable moro or less:to other., '..••..'••••• souroi.»3:of- foal supply. He further-pomted if i®?;' - ; ' ; ;))<?ut that tho existing stock .of. fixed .nitrogen, -<• ; 'represented by..the beds of sodium nitrato or- - : «ai,tpotro ;fpiind dii;. Chili, was U boiiig) rapidly, !&&■■;}£) consumed, and: ho predicted that to remedy,. lossf - recoursovwould chafesto'j be.-hadj to ' • • iho fixation of atmospheric nitrogen-in soino rm suitable for i plant food; i '.:.' ;.v j. :) Sourpes of Supplies. 1 • .;.. " ■ .'>• Tho 'supply, of Chili: saltpatro is not un-', a M^'' , :'tholigh'^ : .vdi^T^rira ; '::6f' : Sivi-i iK'i source's 1 of /sodium.; ■;^:>ij. i 'j{-f : i --- : .'vGhili- !, betis : Vr^-as,' is; 'Xifti:y;th'atVtho; lifts of thP : :knowil;.depbsits-j'ijpvpry 1 i'vijuHhgsthq-'last Itwiyityfycars; the : oxjkjrtiVof i'liitro i'-frphi /pliiii apput'.iiour-' .■ '-'-.■ " times as'great'is'in • thp • preceding : tirenty S 'r^uiremchts'6f_'the ; wdtld-aroi £-')«-;.'.v- 'increasing:' at:^k i aVMagb; ; i'aW;V^'rtbdut';fpur"' '&4\'"- per cent. I'" hayoJ'not'thpiJatesV' • .<•! /:«:•: .' figures, hnt the: present' export' of :nitro"from • "-Cliil| ; .lioOO l ■ v.'-)' sont rato' of consumption' it 'irbStiitiatetl 1 'that ' : : \ thp' supply ;wdl'''be' completely eiliatisted by' .-.-. •. .-)•': tho'year 1910. V;j'y:X:i Ammonia Has Other Uses. • •' v ' .nitrogen': ; and- -this 1 '-y!,^-'\is/ J from ; tho*; .•' .w'asto liquors of gas'works. ..In tho form'of; i •.. '.'ammonium sulphate it is a valuable fertiliser/ ; :demand7foriammonja k ;. ; alsb : ;iricreasing;yery: '• .' ■ rapidly,;- arid", tho' production of g:is .and of gas . •products , does.; not'-tend'toj t'portipnatel;f«id 1 '(ih'erefor.b. : :':-tKis;\:source' pfi:: '■'• ; Mirogpi. is;'.not:' likely :to' : bp,' of ance in' .the''futiu'o in;, tho ; solution 'of - this problpm.-;;V-::A'v>"-; : -vA- : -;>i-T;' s P'f; ■ A Problem of the Futuro. • , . In the address' referred .to Sir V/iJliam' Crookes said: "Qlid present acrcago devoted to'thb world's growth, of wheat is about IG3,- i r^JP--"-ir-. : j';.POOjpOOt--acresV : ".>}V;At.v'''.'tli"o; /.average' iof : -12.7. ; n.-K^^bcls;-por"^*ac^o : /-'.;this^7;gjv(>sv-.>,2,o7p^opp,opb; • ■■■?.', l>nslielsy-; < thirty/years";'!hericp;>'thb • de- : jv-fic; ;)iiand- .wjll, ; b'p'.' 3,260,000,000 .biisiipls';;', and,: • . : ifindiiig"tho-"necos^': : V-lio'-- :^mv' :V^(/i^;Pr^Mt;;yield ; i iSi;: t:,.iv.bnshels ( , ; ' l w,o..; ghould,Tvith..:our|-:prosent: acre-. • ... •/ •" Now. frpnr.l2,7. to 20. per aero .is 'a- > df^ ; ; i>;. therbvis.no doubt that a.'dressing'-with' 'nit- : ■ ~ rate of'sotM ivill this-iiiciijaso and moro.'; v : i'';.>rfiohipf; nitratb f Of improving : . tho yiold of .- has.-, been practically i'ff'ii studied by Sir John Lawes- and Sir Henry. ;• 4i; .' ' .Gilbert' on their •experimental. field at llotliy. -' ariiat-oad. .' ,;This field was 'GOTrn ' witli Vwheat: j ... -.•'•'•■•for thirtpen consecutivp..years,!v/ithput.many'eM^^!.n isWr^:^^il^&i6usliel|- ' '; Vj;.to tho ncrn. , For . the next- ■ thirteen ycani .its -j .soTvij ; with;wheats,and I .'^dressed;witli'scVr.ti' r s^ n P; n :■ 'v-' y le !4'. f° r •;th'ose!:'ypars - whs 36.4 ' bushels : per: i ;'• • . acro—an increase; of ;2i.5 ,bus]iels.:. • v ."'. ■ ■' A Nitrato Famine Predicted. t ? . sf w ca ' ; by. 7.3;. bushels,. aib.put:-/rjowt.j or; : ' pi'ti'atci 'of ;Vso(3a 'annualjy|;fie ' 'appliedr-to:' ■■ . ... . ... ?ach acre..' ; iTKe anw - jint?''reqiiired. r tb ; raise'' v Irvf -tno world's;;crppSpit|l6g;ooo,ooo 'acres fro'in. ■ A the present; supply;;#/2,070,000,000 bushels; -- : ; ' ?2- tllo r oquirc(T':3;2<3oj6oo,ooo bushels, , will: bft' 3. i 2 )000,000 .tons' :; (iiitratp of: soda) distributed • .• f n ■VRrying the wheat-growing ''•••. ' Wtintrios of the wjprid.'! {?'■!•;.' •i' »v??V t * e assume a liberal estimate' for nit- - ijeposit, &£!£:■%. f . 5, y quantity' fltat : -^F9™'.thp.'richpr/qualit^ % possibly fifty years, at,tho J rato of ' ; i;:i''v : '>v-..'-*l on .^° s '' a iio. . ®ngmpnt;tho-wprld's .supply to this' •■ •' : • • ..point demantl«l thirty.• -years' : hence; it ! will ; .... ■ not last more .than four years;" • i However much we may discount tfieso. esti- .» " of Sir. : to •' ■. • thp spread ,of .population and of railiyays over - : , .;' • great , areas; olvtltb wOTl|!s-t£iSacet;hithortot i k-:% '' V® es^.ion ; dnij, ,a,ll?ofcligr causesiv,! ■; v; ... ; the .fact ■ remain:!; ?jpbi,'f ar: diso . V;. ar ?t .Tvhe'n' .the Icpown',: Hifcro'- 1 '• spn will be, .exhausted,.'■aiid' t will'. liavo to be sought • < i^-" v ; '' ?i ; \ }. K Ur. Soils are being , ■,V i '■^^^.9^^f^^^kl)^)o«sidercd>tSrom : ' fen-•' \':v ■:?: thai^-the kb^ 1 • str^ti^iprjmtrpgem,.from-Nfclio . Soil. : ; 1: .■ i s:/: ; S^stiftnii^'fSr'aß.ie'.relates to I'ijihco, iias" ' '.../ ~"''.<1906), ." " '* ! -flibivt)' -v'that^toe;crop3 Har- : ; ' . . .vestcd''.'up'on-tho culfivattd area' or .Franco abstract fjoo,ooo'.tops^df-^ ; - . in, round, niim rom r .thoPsnil!- ft, is j'S'; T N; r proved jthst; stable '•'■•. to 'Z!k'-' X thp;fields,•V.whieh iS/nbtFthb ; ~.••. . icprespnt .more than 327j000'.toiis; .-j'.. : s '; ; Vv ; '. :^^P^f^ipii;ceAsuin#^^23b,o66;to represents' .' :?V> ; :/V^-#>^^tons-^f-jHt^gqtt;^lii^ L thb.yofiai6m;y '.'v ; - ,"/3>PPP,'O; 'i'horamount ' importcdrfs ! ■' .v. thus. Qluy'll. per ceiit. of. tho prro-: '• ,-r ivduced ;j3y 'the.. removal oi',- • • Chili ■ i'iS■ .V;':; nitrate-■;is';n;first-jato fertiliser. .. Ono hiiri- ' vV 'fi' i->. ' ■, g'>: e > on ;an_. avorage; ■ ai : meM : .':tixcess of- 300' ; vfi-:.;;- V. to 1 400, kilogramme's of grain, (wheatj-etc.) a'lid ■' ; •.;i B:ii:«rj:fe -S/ r-f' - ' u'H■: The Wealth or the Atmosohere. ■:;i> . a"'adviS'ability^; jifitliiideticf;' iiccessitjS,! Pf i. supplenie'nting; thp„supplyj of .available Epn ,has, long;, occupied': jbP ; ' ;; " t-but;.it is( .thiit, ' ■ '•;■':•'practical.,'effect becri-' given -.'tb ' : ; '. . . blcm.. '• !he enpfrnpiis .quaiftity. of: free; ' J';;. E°n. which everywliero _ surrounds..ns .lias. al-'. ; J.- . ways appealod to chemists as the source fxonl' ' . which all their supplies wcto in futuro to 'be ; ' . ■ .drawn.. But.rnitrogqri.is'. a lriost'inert coni- , , , pound under ordinary w conditions,- and the- ' v . • ...difficulty. has. : hitherto. 'been '/to/canscit ; ; ;;7.' 'ventor..into,: combination with'•'■oilier- element-'' • arj- bodies ill'sueh"a • way that.it could be' : ' V. Utilised' as -plant .food. , Within recent 'years'v.; ' this problem has been .solved in two ways; ' ' . Cyanamide Discovered. •'• .• By-taking 'starting.'point'tlfb powet' ;.. ..; .possessed by; several.;:metals ,of.; directly, fix-' ' .inS- nitrogen,; Professor-Frank, /of. Berlin, 'in' ■ . collaboration with Mr. Caro,, has been Ictl to .' tho discovery of his. beautiful.'inothod,-iianiojyj". tho introduction/'-.'of 1 calcium ;car}iidb as ■ ijh. " ' '":■ .•:'; : ;.al«orfe^t'\of;'piir«'nit^enV*'.';.^t ? heat •- I • tliis substance .absorbs ' tho : nitrogen sup- ;•. I .: / plied' to it, : and-;is; thereby; transformed into ' a compound kiiOTfii as cyanamide;: 'Tlris siibstanoe;; readily' iindorgbes., bhemical clmngbs. .. . •• . For.instance,: after being., timo in tho. I. soil, it decomposes and . forms ammonia^. Calcium cyanamide can therefo'ro bo einployptf ' - directly' as; a,fertiliser,.;;and- is .manufaptured ' ' \-for this -purpose by •~tho';,.oy^hi3geaajschaft .■, in Berlin, whencp it . appears upon tho m:|r r . ket under the- namo or iime-nitrogen or • •'■KalkstickstolF.'V This substance''is valu-' : V .; • chip, as a fertiliser ..if _workod into the soil'a'.; ■ short timo before.it is required, but if apf,, : plieil to living plants as nitrato of soda :is ' ~ ;o<^mohly/'topM^Arts^isti'' h actwn-.i9 'dis-',. itinctly.. dpleteripus.f:, \ Scientists at• Work. ;;' ■■■■;■■■. Tho.other mode in:which, nitrogen may bo . fixed very simply? is by causing, it to unito' with. oxygen m tho electric arc. • It is in-'.' ;'• ; . teresting to •.rccall.'that,as far back as 1780. Priestley,and Cavenilish'.pxbdised.iiitrcsen by-

means of "electricity. In his •" History of t Electricity !, :(4tli*lilition'),'published in 1775, Priestley says I liavo demonstrated that , tho olectric matter?is, or contains, phlogiston, by showing that it affects all kinds of air as phlogiston ;doßsjA particularly diminishing cbmriidn ,a : ir and making it nox- . ious, ' so as to "m'Ako no effervescence with nitrous air.-" .' fft '1785, Cavendish says j -' When .t-ho -clcbtrip spark was made to pass .) "thrqugh, bcomnum air, included between I, cbliunus ),pf,,'!itmus, the ' solution ,ac- .. ~9'jirid. a. red -colour.,- and tho'air was dimini- ' "shedr cbtifdrriiably. to what.was .observed, by > Div Priostley."' ' In 1790, I'nostley, in dc- '• S6ribing.;'the' ; eifect-of the electric spark in '.•air ; ,.say^;—',',3lr,ii,Cayen(lisli.has:provc(l that ~ jii this process by i .a f unipn;^pf)flip, l 4ep)ilogistic'atc'd ahd)plilbgistii ca'ted'air in common air.'' ■ ' I Vltnr ,11.1,1.,.-. -,il\, , ' ',' . • Practical Tests. 3 • i One-'iiiincired years elapsed boforo -any real advance was made in this position, when Spottiswoode v'-and - Dewar. produced and stu(Ji i e.4 s ,plpctrip i ,|la')nps in air. v ßut-the lirst : praefeal demonstration of. tho possibility of n ilixing:;'iiitrbgeii>,-iiv.ian. economical .manner, in. . prppoi'tion- tb lth'e'.amount. of electric, energy expended; iiwas'.rpublished by Lord llayleigh ■ >iii. : lß97?;v.v,Hisi: experiments led to a .great ' nuniliei'cof;r-sDientific : - attempts' to. reduco tho f'. problein 'to:ia commercial '-basis,, some seeking , to: s'olveVthe..condjtions .requisite for the attainlncntn'of th'a'r ihpst output, 7sdni.e,Tt.akine;;;dirijct,vsteps, towards a , whole-, s'alo*■ -syh'ihet'ic''/production of', saltpetre from tho atmosphore. , Three: of .the latter may hero bo reiorr'ed t"o. " ).' . What was Done at"Niagara. ; ; • 11 ';MeMM;;feadley|;and'Loyejby,)eniployed 1 ;pbntiriuQus cii'rrbn't) at a; potential' of 10,000 ;tplts..))',i'lip (liiliculty.of keeping discharges at -'suoliV-isy-ei-y great.' ,-Tlio idea, running; all. through -.their I ')experinien£s i ''was; ! ;'the l 'necessity)'.of 'Obtaining, '^lfc'ptwc^'^riis, J of .'itliQ:'greatest ,;possible;.len'gth d-"j th'^V^JfiaUe)st'" possiblo section, in- order possible . voluinb- of, air ;)nji^-lit-'b'e contact with ■: tho surtlie arc; ; ' t -'A"company with 'ajconsidcrva^ip/capiiat^caliedrihpAtmpspherio.Products to '. work ' this process, factory at' Nia-: gafa;. ilKufc',"' ojifiiig.'to.'thn) bonip]icated)appara)tiis; high cost' of maintenr ) of : nitrato was; ).)tho' company ceased 'operatipiis 'in ! ilip')summer of 1904. .. . ' A .Wioro • Succossfui "P/iethod. . .Syi,. .'• : )• , Messrs. : 'Birkeland .and Eydo produco.. a ■)peculiar form of high-tension flamo. by; using two jwinted popper' electrodes, attached tb'ii high-tonsion alternator,; placed;, equatorially;' (between tho,--poles of a powerful electro--:magnet'.";Tlb:.v,'orking potential employed., is; ■)0000 "v'olts;vand' : thPVcu.rr.ent ;is.an alternating', 'oiirront' of''SOvpdridds ppr'second. -,Th6)'olec-, grade's 'afb'\Spdled'"-witii water, -which, removes :dboVp'.7i;<-i)brveeht. "of the''clcctrio "energy;in: ' 'ithp'f'drnrof-'lfßatr.^'f'-i:.; I .') ')'.')' : ;.;, : ■' Vii'i fw-.-j;'... :• . ' ...-yM'-'.:'. *;.r : A l-inal Triumph. ,/i: ( T)ie;,practical)utilisation of this -procoss. is- • now bping caraejl.' on ; at' ; Nbtodden, near. ;.^fenclat,' : -mahu- • '.faefpry,. Ra's'.'.bppn' )ijistallqd, and . three. / fur-'. : '-.kilowatts, ;aro) m v^i)^«]^V.^jb^?^ l oV;->-'-^fi^ric>''bsidp. t fumes. )are, J. ).tlies'o, after cooling, ; absbrl))va' fur thprJquanti ty.,'of oxygen from the ltiu^i'ndiiurA'itito^^tcpgen,. : .perosido';.; this, iion- wlditipn) nitrio.'acid. ', Tho ; ' ;details)) : of:i:tbei; piwess),-need;,.not; 1 bo con-; say,) that .tho. prtficohtaot; -wit-h". ,-niilk, of. 'linie ibj^j; ard absorbed,-. ' splutipn -is .coii-'. po.usiden(blyiriin "iiitp; ."'and t in ithis''. • fprni, appra.r'sv,bn j )vtho.;ma'Vkdt. v)Thb" nitrato tho centrisalt, and this is of confusion and it '.'into '-a ,; basic )r saltj''i|; r j^bduccd/'asl a; .dry.',? powder, fVyhich; i^^a^il^;«:scattered;,'by ; . a'c'soinng ..'-i, r-..'-' )^ ti ( CheapV tiian Soda. ' ; 13.2 per'cent: ■ ofi:iiitrdgen,f;eosts - in 'Noi-way\about £4 -/psr) seHing'.price is in Lon: ■ :don v of.'vsMiumifriitfate;, oil .' a 95;. perXpent). : )b'f-;.nitrbgen,'-.'. ■ is?£ll : ;10s);} This; is i'Vory; nearly'aVunit ;value, ,{pf4ss.,'as.';agiinst,-'i a; ; . littjo ' over .-).125-.-.-'.i for-. .; calcium nitrate; ./.or.- . - . • )))-^i.u)'.-_ , ; ■ Tho Ndt^d'pn;. works liaye pfoyed 1 . so satis-. ;a. . 'hew-factory : ,-VwlMi-is to obtain about 30,006 horse-iwwer. from of. ,tho"Svaolgfbs,, . about ;liyd\ki.lombfres distant. .-By utilising this v'ast .pbwer'':tho--cpst )of construotion and will bo much re-, •duced,-and'-th'o iiltrUt'o of calcium iwill bo pro-,4pcpdj'at.'a--.cpnsidbrably..lower post 1 • than-aV prpsiput. !;vV'-Ty;e )'-• ' iA.ißjiial ,Br.ocess.-.i,i.! '.),■). :. ■ ..- ■»'■ of Pi-'ofessor. Kowal- 1 ;'slri"anU;:M?- Mc-scicki, of Freiburg)'. Switzerpublic,-, except 1 in i tho, technical' papdfi published■ by tlioni., • But :4hoy'»h'avo'' a beih o .ivo'rkin2 on : tlio^'principlo., -ftliatpths^mitput^jbl^iiitric; oxide with a largo 1 periods' "is better than'with'tho - , uSual : .'fl.titab6if. of' jieri'odsrfroni ordinary alter-. n'atprs't'-.'tThey)''have,,.-thereforo, been em-' ploying high-tension flames, up to 50,000 volts ; of-from ; 6000 to lo)oop a pi'i^ls , ' , ,'':. Q)lio difDciiliios ■coonwtM' 'very;, high) voltage arc • great';-'and;';',,up ; '' J till ; .rpcently the; results -vehy, encouraging,' had 'iiot ' bowi'' stablp-'e;iidtfgli-''to warrant, the'" utilisation ''of , 'thoii'Vpfbcess' ! 'Oh) a' cominercial scalo. patient research those, now been) largely overcomo, 1 and-';i'n A'Jaiiii'ary-: ? bf this i,year .it-' was an- 1 npunced'''that i - ! th'oy llad .suctoeded in " pro- 1 ' ducing pui'jDj.lcppcen.tyated nitric acid from the' -. 'Ilio .term "pure cbncpii'tVatel'.'" ip tliis ''statement- probably requires modification, for it' has . been found at Nptoddeu:'tlrat)'it' r ls difficult .to- cxceed 50 per ) c'o&o./,.Jtjtriai .!jcid-,' laiifl, inipossi bbo "to-ge't\coh-cen't'rafed; acid: : ; Tne,''iisual) strength of '' acid ! attai.ne<l .'i^ : !abbut : 40, per. cent. : | .and. in tho ' in,T,nufaoturo-'' of-';'talcium ' nitrato oven this , ; ainouht:oi : cbnce'ntfation is not necessary,: as -tbo.re' l is;abjin"danfc : hcat'dovelbped invtho fur- ' nace-'gase's- for 'the"evaporation' of.'tho'nitrate ' n ; ; V 1 -',. : . ' - .-v : /. Contemplated. • "' Tn*^i fiSfe'gso?).j qK the'manufacturb of.' nitrib'; ftci'cT/.'Eiiid ))nitratGs). fr'bni . the ' air,cheap M' :a'nd it is only. Ely) :i to 'b,p).established' in -thosecountries' ; is available in large quan- ■ In "'Europe, "Norway; and : Switzerland alptfb : .s'i|pply )tno")re'q'yired conditions j'whilb in 'th; 6' Si l utlibfii''Hemispher'e New. Zealand'.is.pre-, eminently:;)suitable,,; Cominunications liavo 'already l^)Keen v ) entore'd..into with the) h'olders ' ofltEo "patent)'rights of'both) the. BirltelaiidlEydb?''and), processes, : -'and''''bn'fc;pr'p"thbr-pf; these will probably , bo seCi]rcd-.;eroipitg); v pl '.')' ).;' ; ■Importanci of Nitratos. ; -"-Jlpanwhile, -it may ; bo interesting to consider tiio,-iiiipprtaiico; of nitratos in agricul- " turo.generally, mid their- applicability .-.to New .Zpnllatad an-particuliir. Hitherto, the discus)sipn.carripd on a:j tlie result of Sir William iCrppkes-s.-.ihomorablo address, has referred .-production .ofnvheat alone, as that is 'thb.nipst-iinportantvfood material... to 'tho .wlitp.-.racesj.pf. tlie 'world. . .If : we .extond: tho--field of inquiry to- other crops . besides wheat, we find, as the result of exporimouts made by Lawes, Gilbert, .(Jp'oko,, and other, compotent. observers, that )tlx« sodi.um'-.jiitrato. greatly increasos the yields.'':. Thus-with barley, the application ■ of .lcwt.j-ofniiitratb per .'acre-gave an increase ,aybragiug.:.B,,bifsheli' of, grain, and 2cwt. gave ' i i4,:.t)ppbeJs,-iL-Witluoats it is stated'by-Aik- . "mail that probably upon no other crop is nitrato Vso r safe',, and oifective." In the Rotliiipisted iex])e)'imehts, it was found that whijq. o!v;onc field,.-; unmanured. land gave an javorage,yield -for: five- years of 20 bushels per „acro,. the-'additioiv,of scwt. of iiitratc.pF. soda ),to.,a.',cprrespt)nding,(pieco' raised the yield to •17-busliol.s.- On another field, tho unmanured portion' , yielded - J3J- bushels, ■ whilo .that .dressed, iWith:-:2icjv.t.,.,of nitrato gavo 26* )jnisbels:,.; In-'grassi.lands the average yield ,of .dry; hay.on unmanured -meadow over a .period of ;36 years, was 23iowt..per A corrcs;pppding 4rea with 2Jcwt. of nitrate ;of ).sbda;:gave 361c?;t. of hay. Thoso figures •)apply>:' to-T,Groat- Bnitaiii) and may not bo. rstpictlly,v applicabld',.tp New Zealand, whoro

the soil conditions may bo somewhat different. But, making all allowances for any likely differences, they present a problem of enormous practical importance to stockraisers. An increase of 55 per cent, in the. stock-carrying capacity of a farm or run is a subject worthy of national'consideration. New. Zealand's Manure Bill. The quantity, of sodium nitrato and of ammonium salts hitherto imported into Now Zealand' Ims been small, and the greatest amount of attention has been paid to pliosphatic manures. The total value of imported manures in 1906 was only £210,000, and probably not one-twentieth of this was nitrogenous. A good deal of tho latter class of manures is locally produced in connection 'with the frozen-meat industry) and these are used in admixture with imported manures, chiefly in fertilising arable lands.' Almost no manuring of grass land 3 is done, 'so that the 'problem here is in its initial stages. v ßut the question; for this country is to ; make the land carry moro stock, and this is to bo accomplished by enriching it. The extent to which this is done'at present is very small, as' : the following figurtt) show:—The amount of ploughed land sown down in grass and 1 clover •in New .'Zealand in 1906 was (in-round ; numr hers) 4,725,000 acres; of unplough'ed, but sur-face-sown land,- 7,850,000 acres ;• and of native' grass, tussock, etc.,- 22,900,000 acres. The amount/of cultivated land iii other crops than grass was about' 6,480,000 acrbs. If wo as-' sumo that fertilisers'are used on this/latter cla'ss of--lq.nd - alone, -tlieu- the- value of imported manures employed, in .Now.' Zealand works out to less than 8d; ; and the weight to less than:2olb. avoirdupois per/acre. There is ovidentlv vast robm for expansion tliere.. n; •' ' '■ ' ■ . : :". ' , Importance of Lime. ' - Of, course, thero are other well-recognised sources' of manuring); which cannot bo. tabulated.,; Tliere is tho vast amount: of nitrogen-, ous, material 'in; particular wliiph is returned, j:o. tho land 'by grazing animals.Then tho addition.of Jimo to tho; soil .is ,of very gre?it , I'aluo, not- only in warming the land and in destroying the excess of vegetable and poaty matters,. but- also, in,-liborating .potash.-salts, for'plant use. Clovers and other leguminous plants' especially;require .lime,' and by'their root-nodules thesp plants striiV-up' a vast amount of nitrogen in the, soil, as well as -in thp bodies 'of the animals which feed on..them. The extension of- clover cultivation and tho liming.of clovcr-carrying ; country are,;thereforo,.of tho greatent possible value in improving , the': stock-carrying- capacity of ...the. country. This. is the direction ;in. which, th'o Agri-; cultural Department looks: for tho increase of tho productiveness 'of tho lalid,. but, it;will not bo' foulid to bo rapid , enough, -unless ■ greater, facilities are found than, exist at presdnt for better distribution.of limb'.- .:: • j .In this connection ono great, advantage of palcium nitrate is that it provides a certain 'proportion of. lime in.addition to its nitrogen, and)its application • to tho soil ..is tlierefora imore, beneficial even than that of. sodium nitrate. ;. ; ' • ... ■ v . ; ; . v Annual Loss of Nitrogen |n How Zealand. Thp quantity of nitrpgeil which is removed from tho soil of .New. and exported frdm our shores, is very largo.' In'frozen meat' it'-amounts:'to about' 3120 : tons' per (innuni) in ; grain : 450 tons,\in cheeso 292 tons,, and in wool: 5405 tons) or a'total -of about; ,9267.tbn5.,. It .wbuld' tako.over.7l,ooo tons of. calcium nitrato to .produce:'this amount: >' ■ Once the value of nitrogenous fertilisers is . s fully-'realised, the amount of calcium ;used. would vastly increase,-but' it is npt; tliat at. present-, and• until,.its value is appro-. , cihted,' a factory' J tiirniiig: : opt, say,) 5000 tons' p«r' annum,, equal to about 660 tons of. nitrogen, .would swamp 'tho Now;' Zealand market; 7 V''..,:. , 7' \ The Loss in Australia. • ■ ; JJut -when '.wo turn •' to .Australia,. wp' find enni;n)bus , possibilities, for : . thouse)i of, nitrogenous manuros. In ,'190oy ( . 'tho.-V>' t A.ustiralian : Commonwealth exported 17,260 tons of nitrogon in the-ifdrm-bf .v/opl,;'pnd- 62,900 tons, in . considerable, amounts , in ,tho form,ofJniea);;and l chfese. Of. Jliis tho-greatpr, pf°tho' irb'fl pf 'iflMt is. dr'awnv ! .frpm r 'nnc'ultivatcd.- land.-,',; . i Sly, fignrps.for l)oth, : Npw Ztialancl aiid'Aus-' 1 ■tralia pro based on'thp trade : returns of. • and- oil"th'e ,A calculation'. that'' tho': amount : .'of. nitrogen present' in; the , variops sUpstances-'is : as: follows .wool;'- 6.65 pbr qent.>;' injfrozeiv meat, '3; -ill che050,V4.45 ;-.in'-; wheat,' 3.; -m ,-'oiits and barley,- .1:38; -attd, iri' -maizo, '1.78.' iTheso are 'approximately; adcurato estimates. '" ' Y :; ' ' •'•' '■' Scope for Cyanamide Works, i: ! . .' ; ~ - 'If wo-consider tho Australian;grain oxp'ort alone', of; 62,-900 'tons;of nitrogen,; and remember that' all this 1 comes from land .'in: cu}tiya: • t'ion, then tho I' jiossibilitios which . present themselves of increasing tho' yield at least' 25" per.cent. by'thp addition of ,icwt.';or.2cwt/.of. . ealeiuin .nitrato to the soil).:.ouglit surely' to stimulate' agriculturists'' to acKievo this im ; . proved result, /if ' possible./ Tho'. impbr.tancb, also of establishing.'works' for. tho manufac-' ■turo. of "this' substanco in New country': specially) adapted for'it. in tho Sputli- ' ern ■Hemisphcre7- L beconies : at onco apparont;. It''has -been said that' tho timo'.is not 'ripo fpr '..such li'orks.' Things movo.so fast, how-, over, that this statement is' hardly'wortl! considering. .The timo is not'only ripo, .but tlie preliminary steps have already been'taken, and'it .is hoped by thoso : interested -that it will be possible erb long to report a forward move.' •