T'S liix im CITY OF NEW YORK BOARD OF ESTIMATE AND APPORTIONMENT STANDARD METHODS OF TESTING RUBBER MATERIALS JULY ilSMi 1917 ISSUED BY THE BUREAU OF CONTRACT SUPERVISION A ROOM 1327 MUNICIPAL BUILDING j.^^pas". D. of D. SEP 18 I9U PHYSICAL GENEEAL. The contracting department shall select and take all samples for testing. The number of samples and the quantity to be taken from the deliveries will depend upon the size of the articles and the quantity delivered. Upon request from the testing laboratory the contracting department shall furnish any additional samples required. Samples shall fairly represent the delivery and pieces shall be taken from not less than 1% of the number of imits delivered. The results of tensile strength, elongation and set tests, as reported, shall Averages be the average obtained from the samples received by the laboratory. Not less than 3 test pieces from each sample shall be tested and their results taken in calculating the average unless some individual result is apparently in error, in which case a retest shall be made. Physical tests of rubber shall be made with the temperature of the air -^mpetaum ot not lower than 65° or higher than 90° F., and the test specimens shall be ° *'°°°'' at rest in this temperature for not less than 30 minutes before testing. All measurements of time shall be taken with stop watch accurate to 0.2 Time, second. PEEPAEATION OF TEST PIECES. Tests pieces of rubber shall be stamped out with a die, whenever prac- General, ticable to do so. Test pieces of rubber for tensile strength, elongation and set tests J^^^f^^^'^'^Mt shall be cut out with a die either of the constricted bar or ring type. The test pieces, same test piece shall be used for making all three tests. When the bar test piece is prepared a die shall be used that will make the constricted part 14 iiich in width. All pieces for these tests shall have the backing entirely removed and any corrugations or irregularities of any kind shall be accurately buffed off to make a uniform smooth surface, except the pieces that are to be used for testing the strength across the seam which shall not be buffed. Test pieces which have become burnt in buffing shall be discarded. Test pieces of rubber valves, odd shaped rubber articles, et cetera, shall, whenever possible, be cut down on a lathe to an even thickness of not more than Ys inch and then cut out to shape for testing with a die. If it is necessary to use naphtha to remove the backing or to separate the rubber from the plies, the naphtha shall be what is technically known as 76° Baum6, free from oil. li ' 5 w •pnnod B JO x-q o:^ o^bhiodb si qoiqAi. sii^BiBdclB m uo apBin aq n^qs s:^s^| ^^Tla^s aiisna^ nv .■sra?»J»id7 :sM.onoj SB apBTH aq HBqs pimodnioo jeqqru eq^ jo q^nai^s 9itsn8| jo ^OI^B^T^IJ^:^^p aqx •SNOi>LVJs[iHaai-aa •a^qissod laAauaq^ gnoi saqoui gx iiBq:^ ssai %oti :^TlD aq HBqs '•D:^^ 'Sni^pq '^^a^tSBS ' 'Sni5[0Bd sb qons ivue^vm foif /o saosii 227 •saqoni S/1;X ^noqB loj paiiBis sand 044 aq:j jo no^BiBdas b pnB 'send OAi^ ;iiq n^ o^ ^op psddF^s aq n^qs pnB apm qoui x' ^^o Ip^BiTiooB aq n^qs saaart^ ?S9? 6Mi?28ff •saqDtn ZAX poqB joj pa^iB^s aq n^^s jaqqiu puB Sui^aaqs naaM:^3q noi:^BiBdas y •apiA saqoni S/xI ^^m^ P dii:ts b no apm qoni x Sni^aaqs jo dl^s v gniABai a;isoddo ^i^oBxa paiBdaid aq Tl^qs aoaid :jsa^ 9q:^ 'Jioiq:t qom s/t ^^q^ ^•lo™ si'^Bd laqqni aq; ji ^Bq; :;daoxa 'asoq pami jaqqnj no;; 00 loj sb januBin axuBS aq; ui paiBdaad aq HBqs ssoaid ?sa? Buiopvd xdqqnj, ■pd}pvq ouqv^ •{aipuBui aq; loj ;no pa^up a-ioo b aABq HBqs sdpj^v Miiiwis puv Bmopvd punoj, pyps •aq jCbui asBO aq; sb 'sjjooq 10 sduiBp JO Snraa;sBj ladoid ;iniiad 0; ;nB;sTp qStiona ibj pnB aoaid aq; jo q;pm n^J p9JJB;s aq n^^qs apBin aq 0; ;sa; aq; q;ui aonBpioooB m sja^fBi aq; iiaaiii;aq jo oiiqBj aq; pnB laqqni aq; uaam;aq Tioi;BiBdas y -papnBia 0; no gnipip ;iiniad 0; jb^oiio ;jai pnB 'apm qoni x XpsiaASUBi; ;tid ;tp;BiiioDB aq ^^Bqs sapi;iB iBpniis puB Bmopvd punou. 'dsoii pdddvxm /o sdOdid ■^sdj, •saqont %x ^noqB joj pa;iB;s aq n^qs dij;;s siq; JO laAOo poB Sninij naaAi;aq noi;BiBdas y -apm saqoni %! -i^aoo jo dii;s ■B no paqiii;sipnii apm qoni x ^nrai^ laqqru jo dij;s b SniABa^ 'ouqBj aq; SnunCni ;iioq;iM. 'apis qoBa no j;o paniinti; XjUBap pnB jfunjaiBO aq •[^Bqs g'niiiii jaqqni aq; jo qoni J^ "aoaid aq; jo q;Sna| \\r^^ aq; ;Bg ;no piB^ aq nBO yfaq; ;Bq; os s^bai aq; qgnoiq; ;no aq ijBqs Xaqj^ -aonaiaj -nmoip aq; jo q;Sna^ ipij pnB apm saqoni %x jfpsiaAsnBi; ;no ^p;bitioob aq X^Bqs S903yl jsa? asoi/ pdpwj,q puv sdond i-Sdj. dsoii pami Mqqru uof^oQ ■sd\xii asaq; q;m aonBpioooB ni niaq; aiBdaid o; a^qBOT;oBidnii st ;i jt 'noi;B05pads ;inn aq; ni loj pa^^BO sb jannBin aq; ni paiBdaid aq ]|Bqs sapi';j;B padsqs ppo iaq;o pnB s'p^svS pdpiom 'Sdinjudl 'SMt[Svm wo// sdoaid jsaj; •noi;oajip jCnB ni ;no aq jCbiu imj,9ivm p^srsB j.o duxopvd 'Bmjisg; •^n^nipn;iSnoj ;no aq n^qs saoaid ;sa; aq; asBO qoiqAi ni 'naj[B; aq ;onnBD ;naniainsBain ^Bai;DBid b ;Bq; j^Bnis os si ia;aniBip aq; ssapin jfpsiaAsnBi; ;tio aq n^qs sapi;jB xB^raiis pnB Smipvd punou, 'dsoii /o spuy>[ ny : SAiojpj SB paiBdajd pnB ;no aq ^Bqs s;sa; noisaqpB 10 notjouj joj saoatd ;sax •Sngjnq ni ;nmq aniooaq 0; aoaid ;sa; aq; Aio^B 0; ;on nai[B; aq jpqs aiBO ;Bai£) •Sni;sa; aiojaq sa;nnitu ox ^^q^ ssa^ ;on joj ;sai ;b niBinai n^q^ saoaid ;sa; aq; 'anop Snignq pnB paAoniai si §ni5[0Bq aiaqAv sasBo \\^ nj •Sni;sa; aiojaq inoq x tiBq; ssa^ ;on joj ;saj ;b trxBinai 0; paiionB aq n^qs saoaid ;sa; aq; pasn naaq SBq Bq;qdBn naq^ saooid %en noi^otjj Grips: When bar test pieces are used, the grips for holding the test pieces shall be such that they will tighten automatically. Ring test pieces shall be placed over the revolving rollers or pins pro- vided for them. Marking the bar test piece: The bar test pieces shall be stamped in the center portion with two lines 2 inches apart, using an ink pad stamp. The distance between the outside edges of these stamped lines shall be accurate to 0.01 inch, and the width of the stamped line shall not be more than 0.01 inch. Measurement of bar test piece: The width and thickness of the test pieces shall be accurately determined at three points equidistant between the marks. Measurements shall be accurate to the nearest thousandth inch. Measurement of ring test piece: The width and thickness of the test ring shall be accurately determined at not less than four opposite points on the ring, care being taken to get the minimum cross section as near as possible, the area of which shall be used in computing the tensile strength. Measurements shall be accurate to the nearest thousandth inch. Breaking: Bar test pieces shall be tightly fastened in the jaws and brought just taut. The machine shall then be started and the speed so regulated throughout the entire test, that the jaws separate at the uniform rate of 20 inches per minute. The number of pounds necessary to break the test piece shall be read off to the nearest 0.1 of a pound and computed to pounds per square inch, using the measui-ements nearest to the break. When breaking the ring test piece the ring shall be slipped over the revolving bearings provided for it and the procedure continued exactly as for the bar test piece, the speed being so regulated that it will give an equivalent elongation of test piece per minute. Bar and ring test pieces shall be prepared as described under the caption °^^'^°n^™ °' Preparation of Test Pieces, except that no buffing shall be done. ^''*" In cutting, the seam shall be centered in the middle of the bar test piece, at right angles to the axis, as nearly as possible. The center of the seam shall be made to lie along the diameter of the ring test piece as nearly as possible. The number of pounds necessary to break the test piece shall be read off to the nearest 0.1 pound and computed to pounds per linear inch of seam. The elongation at the breaking point shall be accurately determined Determinationsof during the tensile strength test as follows : breaSngpoint. * On the bar test a rule graduated to tenths of an inch shall be kept opposite the two marks and the distance the outside edges of these two marks are apart at the instant of breaking shall be noted. This distance shall be computed into per cent of elongation, i. e., if the marks are 3 inches apart at the start and 12 inches apart at the break, that piece would have a 500 per cent elongation. -lo 2 X 100 = 500 per cent. •pipuCTa B JO pB9:jsni diUBjo b q:^m pBsq ja^od eij; 04 pana^suj aq n^s^s sssaij }S9j, /o uoi}mvdd.ij JO noi^fd^D eq:j japnn paquosap sb paiBdaad sb aoaid :^S9:^ Qv\} JO DuqBj 9q; pq| :jd9o'x9 'sdOdij jsaj; miuomq puv ssojj Udqqnn uoi:^dBD 9q; lapnn Suiogaioj aq:} ni p9qiiDS9id sb %obx9 pa^sa:^ aq \\^^b jajoBiBqo jByiniis B JO saoatd :}sa^ puB sao'aid :^sa^ asoq aig pautx jaqqtu no;:^OQ •paijBJBdas aq n^^s sia^B^ jo laXBj uoi^ouj aitjna aqj;, •aaiAap Suipiooaj ot;Brao:jTiB ub ho papjooai aq R.'sm pBOj siqx •pa:;BiBdas q:jSu9i ^b^o; aq; jo o^q uBq:^ \\-^-aa\ p;o:} i9;b9iS b joj ;u9ra9jmbai uoi:^BOijioads aq:> Aiopq n^J ■Jon saop |i :^Bq; ©as o:^ paqD:^BAi I^^ubjshod aq ^Bqs pBoj aq; saonauinioo uoi^BiBdas la^jy •(pBaq j9Avod aq; jo pagds) a;miira jad saqoni oai; jo ajBj niiojitm aq; ;b uni antqoBni aq; puB pasiBi aq n^qs saqo;np ;qStaA\ aqj, •pjpnBni 9q; jbao paa9;nao pnB gui;siAi; ;noq;m auiqDBUi §ui;sa; aq; jo pBaq Snipjooai aq; o; pgdraBp aq n^^s 909id ;s9; aq; jo pna aaij aqj^ •pB9q laiiod aq; 0; paqoB;;B irid B o; no paddip aq n^qs 8o«ld ni aoaid ;sa; aq; q;;* ]aipuBra aqj, •naxnioads aq; jo aptsni aq; sb ja;9raBip araBS aq; jo puB aaaid ;sa; aq; uBq; iapu\ qoni % ]8jpnBui b 0; no paddies aq y[Bqs saoaid ;sa; jb^diio paddBiJii j9q;o pnB asoq jaqqru \\y :9unp990j.^ •9niqoBni §ni;sa; a^isna; ■B no apBin aq ^'^qs s;s3; q;Saai;s uoisaqpB 10 uoi;oiij hy :snivj.vddy : SAO^oj SB apBui aq ijBqs oiiqBj jo sia^^B^ aq; n99m;9q 10 ouqBj aq; puB laqqni 9q; n99M;aq q;3iiai;s notsaqpB jo not;Duj jo uoi;Bnnnia;ap aqj, ■siaq;o j£q paoBfdaj aq j^Bqs saoatd ;s9; aq; s^iBy JO Tioi;BAj:9sqo aq; nuguoo s;s9; gq; jo s;p\saj aq; ji pnB 'sjoajap 10 SAiBg JOJ pa'nnnBxa aq n^qs sSnij ;s9; pnB sjBq ;sa; q;oq jo saoBjins najjojq aqj^ •apBni ;sa; jaq;onB pnB 'noi;Buinija;ap inB JOJ aAi;oajap sb pajapisnoo aq ^jBqs n9niio9ds 9q; ';s9; q;Sn9j;s a^isna; aq; Snunp aoaid ;sa; jBq aq; no sjfJBni 9SbS gq; apis;no sjnooo ijBajq aq; jj •;naD jad x'O ;sajB9n gq; 0; papjooa.i ;piS9J aq; pnB 'ain;dui ;b noi;BSnop jo ;naD jad aq; Xq papuip ';nao jad jpq ;sajBan aq; 0; j;o pBai si (;as |Bn;oB) q;Snai ni asBaioni aqj^ -Suu jBntSiio aq; jo ja;aniBip apisni aq; sb j9;araBip aiuBS aq; jo ostp pi^os b pnnoiB pgjnsBani A^pijajBO aonajajuiuoip janax aq; aABq jjBqs saoajd ;sa; Snijj •;nao jad X'O ;saJBgn aq; 0; ain;dni ;b noi;Bgnoia aq; jo aSB;naDjad 0; pa;ndiuoD gq \\v\\s pnB ';as iBn;DB aq; si saqoni g snnini s;n9inajn -SBam om; asaq; jo niiis aqj^ •noi;jod jgq;o aq; no ;niod najjojq ;sajBan Snt -pnodsajjoo aq; raojj jannBin auiBS aq; ni puB 'qoni XO'O ;saJBan aq; 0; noi;jo(i ngj[Ojq gno no sixb aq; gnojB ^[pjgjBO pajnsBani ;niod na^^ojq ;saq;jnj aq; o; anil ^^^ P 9pis;no aq; niojj aanBjsip aq; aABq ^^qs saogid ;sa; jBg •qo;BAV do;s b q;m naj{B; aq XT'^qs aniijL "Sni -i[Bajq ja;jB sa;nniin s^T ^^R^ ^-lo™ -ion x ^Bq; ssa^ ;on ;sa; q;Snai;s ajisna; aq; nt najjojq sb aoaid ;sa; aq; no aq ^^Bqs ;as jo noi;Bnnnja;ap aqj, •adB; qo;aj;s aq; no pjooaj oi;Bnio;nB aq; niojj ;nao jad apqAi ;sajBan aq; 0; go pBaj noi;BSnoia aq; aABq'^^qs saoaid ;sa; Snijj pani] jsqqiu uo^^OQ -oijj JO aop^arauGiQQ Packing and other flat test pieces shall be tested exactly as prescribed for P""^ "J^ces*''" rubber hose, except that a clamp instead of a mandrel shall be used, and " ^ ^'°''^°' either the fabric or the rubber shall be fastened to the recording head accord- ing to the thickness of the rubber. If the rubber is not thicker than 14 inch, the fabric shall be fastened to the recording head. If the rubber is thicker than % inch, the rubber shall be fastened to the recording head. When fabric and fabric are to be separated, the heavier shall always be fastened to the power head. When heavy materials like belting are to be tested, the test pieces shall consist of not more than two plies of the fabric for any one test. The test pieces prepared and measured beforehand are placed in a hot Dry heat test. air oven at the specified temperature for the specified time, cooled to room temperature, and after resting 34 hours, the tensile strength and elongation tests made, compared with the untreated specimen, and the reduction cal- culated to the .nearest 0.1 per cent. The degree of hardness of a rubber compound shall be determined as Hardness test, follows : A smooth surface 1^ inch in diameter shall be prepared by buffing if necessary. The test piece shall be adjusted and clamped to a rigid base with the test area resting smoothly and firmly on the underlying support. The apparatus used shall be a standard asphalt penetrometer, preferably with electrical control. The hardness number shall be the distance in tenths of a millimeter that a No. 2 Roberts' sharp needle will penetrate the sample under a load of 200 grams, acting for 5 seconds. Tube and cover test pieces for the gasoline test prepared, cut and meas- GasoUne test. ured as specified under the caption of Preparation of Tensile Strength Test Pieces shall be completely immersed in 57 to 63° Baume gasoline for a period of 48 hours at a temperature between 60° and 80° F. They shall then be removed, allowed to rest and freely evaporate in air at the same temperatxire for 24 hours. The tensile strength and elongation tests shall then be made, compared with the untreated specimens and the reductions caculated to the nearest 0.1%. Friction strength tests shall be made on one inch specimens cut for the mandrel test. After treatment with gasoline as above the friction strength shall be determined, compared with the untreated specimen, and the reduc- tions calculated to the nearest 0.1 per cent. The determination of steam resistance of hose shall be made by con- steamiest, necting 3-foot lengths to the steam supply pipe and maintaining the steam pressure required in the specifications, using a properly calibrated pressure gauge to maintain the proper pressure for the period or periods called for. After resting 24 hours the tensile strength, elongation and friction strength tests shall be made on the specimens cut, prepared and measured after the bteam test, compared with the untreated specimens and the reduction calculated to the nearest 0.1%. •9j[Bra piBpuB:js 1BV[%0 lo IqsoiQ jo aq n^'qs sdSnvS einssajd eqj^ •papiODSi aq ^^Bqs (qonr ai^nbs J9d amssaid spnnod m) sso^ ninniixBni aqjj -noi^^Bogioads :|tim aq; ui loj pa^^ra SB aq wxm. a^zzoti jo ja:;aniBip pn^ asoq jo azis jad a^Timra lad suo^^bS ni T[]Suai pajinbaj aij:} qSnoiq:^ gaiSiBqosip Aio^; jo ijnnouiB aqj, -apzon ladB:; ;ioqs ^natn^jBdaQ aii^j Jjio^ ms^ pi'epuB^s b pnB asoq aq:j jo paa aSi^qastp dT{\ tiaaii^aq paqoB;:;^ aq n^^F aSn^S aitissaid laq^ouy -pa^sa; aq o:^ asoq aq:; JO giir[dnoo ;sig aq; poB ;nBipXq .10 ani( paaj aq; naaAi;aq paqoB;;B aq iiBxp aSn^S amssaid y -aoBjins an^^d b no ;q§tBi;s paqD;ai;s aq ^jBqs asoq aqj^ :SAi0Jpj SB apBui aq n^H^ ^BAia;BAi aq; jo ssaaq;ooTns aq; jo uot;Bainiia;ap aqj^ „ ^g asoq jaqqiu qont g puB %g „ 81 9^0'^ 3!-iq^J ^^^] 8 pn^ %8 saqoui 5X 9Soq laqqni pnB otiqBj qom %x jpiT^f 0; aonB;si(i azis puB pnrv[ :Sjii.onoj SB pnij[ pnB azis 0; SnypjoooB aq ^Bqs J[ni5[ aq; 0; Sui^dnoo aq; jo aoatd ^tb; aq; inoij aonB;sip aq; ';sa; j[utj[ aq; loj noi;isod ;Bq; ui pana;sBj ^tjaiTiDas puB jpip[ djBqs b q;m jps^t no ;Bp ;iiaq si asoq aq; naq^^^ •50 ;ioqs pajfniif naqji puB sntpBi saqoui ^g jo apiio b ui paAJiio naqm ';qgiBi;s ;no piBj uaqAV ajnssaid Sui;siuq 0; pa;Dafqns aq {jBqs asoq 'suoi;Bogioads aq; ui joj'pajiBO uaq^ •pa4i0{|0j aq n^qs uoi;BogiDads ;iun aq; ni pa;B;s sb ajnpaooid aq; asBO qatq^si ui 'apBin Sutaq aiB s;uainajnsBain anq^i ainssaid ppq 0; aiui; jo poiiad aq; puB najjB; aq 0; ajB s;naraaJTisBaui qoiqji ;b ainssaid aq; o; piBgai ui ainpaooid SoioSaioj aq; jCjipora sanii;auios Xbiu noi;BDgpads ;iim aqj, •sa;nuini g uBq; aiora ;oa ;naniaiTisBain loj p[aq aq j^Bqs ;sa; lapun asoq aq; puB a;tiuiin lad spunod OOI P ^l^^i 9^^ ^^ apBca aq n^qs ainssaid ui asBaioui aqj, -aSnBS pazipiBpnB;s b q;im painsBam aq jjBqs s;sa; ainssaij ■spnnod oi ^^ ^^^^ -said aq; q;m ;uauiainsBaui jBUigiio Snp[B; £q uiSaq uaq; ^jBqs ;sa; aqj, •paqddB qoni aiBnbs lad spunod oi Jo ainssaid ■B puB pasop aq uaq; n^^js j[doo iib aqj, -adBosa 0; iib aq; aoijb 0; uado jjood iiB aq; SuiABa^ 'ia;BAv q;iAi pa[jg puB dumd 10 aui^ aa;BM aq; o; pa;Daiinoo anij ;qStBi;s b ni aoBjins auBjd b uo ;no paqo:;ai;s aq wbx{9 asoq aqj^ riauuBui Snmonoj aq; ui apBur aq jjBqs ainssaid jooid 10 Sui;sinq jo uoi;Bniniia;ap aqj, •snoiod paiapisuoo aq ^Bqs asoq aq; 's[jbai aq; jo am; -oni;s aq; ui paugnoD iib aq; 0; anp ;ou si qoiqa iib jo adBosa ;oni;sip b si aiaq; jj •ia;BA ui paSiainqns aq ^Bqs 'ainssaid lapun {ji;s 'q;Suaj aq; poiiad siq; JO pna aq; ;y •sa;nuini g loj pauiBjuiBui aq {^qs ainssaid aqjL ■;aaj g ;sBa^ ;b ioj asoq aq; q;m asmq;Sua{ ;no aq uaq; ^^Bqs laAOO aqx 'ains -said IIB spunod o^T 0; pa;oa.Cqns aq jjBqs ;sa; 10 j pa;Daps q;Snaj aqx •Bjnesajd joojd JO 3ai}amq }0 noijoaroilajoa CHEMICAL GENEEAL. Samples shall be taken representative of the lots to be tested. Samples. Blanks shall be run and deductions made according to the lots of Blanks reagents. In the event of any determination not falling within the limits given in checks. the specification, a check test shall be made before the report is sent out. Prepare a sample of not less than 15 grams, taking pieces from various Preparation of i parts of the original sample. The backing of fire hose shall be buffed ofE ™ "' before grinding. In all other hose separate samples of tube and cover shall be made, without removing the backing or friction compound. Other rubber goods built up with friction fabric shall have the rubber layers ground up without removal of the adhering friction compound. The sample shall be cut into small pieces and then run through the Grinding, grinder, until all will pass a standard 20-mesh sieve. Care must be taken to see that the grinder does not become appreciably warm during the grinding. If the natiire of the material is such that it gums together so that it will not pass through the sieve, as would be the case with undervulcanized samples, it will be sufficient to pass the material through the grinder twice and accept all the material for the final sample. Crude rubber shall be cut with scissors. Pass a strong magnet through the sample to remove any metal from the grinders, mix thoroughly, and put in tightly stoppered bottles. Do not expose to sunlight or heat. Samples of hard rubber shall be prepared for analysis by rasping. Hard rubber EEAGENTS. Acetone shall be distilled not more than 10 days before use over anhydrous potassium carbonate, using the fraction 56° to 57° C. Alcoholic potash shall be of normal strength, made by dissolving the required amount of potassium hydroxide in absolute alcohol the day before use, and allowing to settle. Only the clear solution shall be used. Barium chloride solution shall be made by dissolving 100 grams of barium chloride in 1 liter of distilled water, and adding 2 or 3 drops of concentrated hydrochloric acid. If there is any insoluble mater or cloudiness, the solution shall be heated on the steam bath overnight, and filtered. Refined naphtha shall be prepared by shaking out the fraction boiling below 80° C. with concentrated sulphuric acid until the acid is only slightly colored, washing with sodium carbonate solution and water and redistilling. All reagents shall be of C. P. quality. •piOB DuopjDOipjfq p8:)n[Tp q:;ui Sni^^Bax^ id%}v pnB aiopq adoosoioiin B^■\ lapun S9iqg e^qB^aSaA joj noi:;BninLia; -sp ,,sja^{g i^jgnnn,, aq; i8;jb pnnoj s:^u9niSid ^Bianrai eq; einraBsa •je;;Bin 9|qnpsni aq:). jo snoi;oBai pnB SDUBiBaddB 9q; Iq p9:jBDipm osib 9jb :nBqdsB puB qo:nd 'ibx "0:^9 '9:}iqdBiS 'JiOBiqdxnB^ SB noqiBD s9;B0Tpm 9npis9i ajqiipsni j[OB^q y -pioB oii:jra p3:jBi:^u9Dnoo jo •0 -0 OS P^'B jg^JBM. p9niistp JO -D '0 gg q:}m e^dniBS otbiS' ano b :js9Si(]; •:^qSia J9ao qsB^od OT]oqoD[B aq:^ q;iAi p9i9A0D gq n^qs anpisgi laqqru patip aq:j 'notjoBj:jxa ano^jaoB aq:} JayB ^Bp aq^ apBUi si noi;oBi:}xa qsBpd oipqoo^B aq:^ naqA\ j/pBi:}X9 qsB;od oipqoop 'ia:^^Bni uSiaioj,, sb piooai pnB 9:jBpDiBQ •j;o:^BOoisap b ui Sutjooo 'sasBaiont JO ^UB^^suoo si r^qgia^v aq:^ ll^^ni spotiad a;niinn gx ^ '0 oOOX o^ oS6 ^^ naAO ja^BAs. aq:j ui £ip 'la.^uaq pgqSiaAi b o^in i9|ig 'Bq:^qdBn p9m;9j; uubax JO snoi^iod ipnis q:jiAi qsBj^^^ -siBaddBSip piOB ouo^qooipjCq jo jopo aq; ]i:ju[i 9:jBiodBAa poB q:jBq niBai^s aq:^ no j9j[Baq 9q:j aa^l niojj anpisaj jaqqnj aq:f :^ao pBajdg 'fiL2l'0 -lojOBj aq:j Snisn ^^qdjns 99ij„ SB pjooaj pnB a^BjTioiBQ -qSpAi puB jo^BDoisap B nt poD 'apionjo niBpojod paqSiaAi n^ois m ^:^^nSt pnB jadBd aq:) jBqo 'j9;^ba pq q:^m sauii:} oi ^sbm. 'jadBd ss9^qsB no ja;^g jfBp :^x9n gqj, iqSiu j9ao pnB^s o:> aioijy -noiijnps gpuojqo niniJBq :jn90 jad 01 ^ Jo "O "O ot q^iAi 9;B:(idioajd pnB Snijpq o; :jBaq 'anmpA -o -o qOS o; a^n^yp 'qsBAi 'ja:^!^! "paJBaddBsip sBq ja^Bj 'aniinojq pnB niJojojo]Tio aq:} pnB ssapopo ^fjJBan si nop^tips aq:} {i^nn ^fj^ngS :)B9jj -pg^Boipni si jnqdpis JO ^.imoniB 9Sjb} b ji pappB aq Xbih aniniojq 9J0j\[ -gniniojq jo "o -a 9 jo g ppB ngq} 'aqn; aq} jo sapis aq} no iBija}Bni ijb jaAoa o} ("O "o OQI o} 09) Ja}BAi panpjsip }naioij}ns ppy -paAjossip si }OBj;xa aq:} }i}nn jf^naS nuBm pnB nijoj -0JO}qD JO -0 -D g 0} g :}DBj}xa ano}aoB }B}0} aq} SniiiiB^noD aqiu} aq; o:} ppy (jet^vm nSiaio^) en }BJ}X8 ono}sov Extract a 5 gram sample exactly as under "acetone extract" after placing waxy Hydrocarbon 0.5 gram of finely powdered pure copper in the bottom of the extraction tube. Evaporate the acetone and dry the tube at 95° to 100° C. until the odor of acetone has disappeared. Add 25 c. c. of refined naphtha, warm and filter into a separatory funnel. Eepeat the operation with naphtha at least twice and wash the paper with a small quantity of refined naphtha. Shake out with 10 c. c. portions of concentrated sulphuric acid until the acid is no longer or only slightly colored, draining off all viscous material, shake the imited acid washings with 25 c. c. of refined naphtha, drain off and reject the clear acid portion, shake out the remainder with 25 c. c. of distilled water to break any emulsion and transfer the naphtha to the main volume. Shake out once with 25 c. c. of distilled water, once with 25 c. c. of a 5 per cent sodium car- bonate solution, and finally at least four times with distilled water or vmtil the washings are neutral. Transfer the naphtha solution to a weighed Erlen- meyer flask, distill off the naphtha, add a small amount of alcohol to the residue and evaporate rapidly in a slanting position to remove water from the wax. Dry at 105° to 110° C. in one hour periods to constant weight, desiccate till cool and weigh. Calculate and record as "waxy hydrocarbons." Extract a one gram sample as under acetone extract for 4 or more hours. Mineral FUiers. and dry the rubber at 95° to 100° C. until the odor of acetone has disappeared. Transfer to a weighed centrifuge tube, add 50 c. c. of aniline and 10 c. c. of nitrobenzol. Digest for 20 hours at 150° to 160° C. with occasional stirring until solution is complete. Cool, fill the tube with ether and centrifuge. Wash and centrifuge at least four times with ether, stirring the pigment up thoroughly each time. Dry the tube to constant weight at 100° to 106° C. Cool in a desiccator and weigh. Unite the decantates, distill off the ether, transfer the residue with the aid of benzol to a weighed porcelain or silica dish, bum off the organic matter, cool in a desiccator and weigh. Add the weights of material found in the tube and dish, calculate and record as "min- eral fillers." One gram of finely ground rubber sample is placed in a weighed porcelain (^*"e™|)°' crucible. The crucible is covered, placed upon an asbestos pad and heated at a low temperature to drive off organic matter. The lid of the crucible is removed and the edges of the crucible heated to burn off organic matter. The ash is inspected for any unburned charred matter and, if necessary, is reheated. The crucible is weighed after cooling and the percentage of ash calculated as usual. No correction is made for sulphur in the ash. Mix a 0.5-gram sample with 6 grams of potassium carbonate and 4 grams Total sulphur. of sodium peroxide in a dry 60 c. c. iron crucible. Fuse by heating the surface of the mixture a few seconds with a burner. Cover and heat to quiet fusion for 15 to 20 minutes. Eotate the crucible while the melt solidifies. Cool, place in a casserole containing 200 c. c. of distilled water, and heat gently until dissolved, lifting and rotating the crucible to accelerate solution. Add a few drops of alcohol to reduce and precipitate the manganese derived from the iron, filter, wash well with hot water, acidify the filtrate with hydro- chloric acid, using Congo paper as an indicator, dilute to 400 c. c. volume, heat to boiling and precipitate with 10 c. c. of a 10 per cent barium chloride solution. Allow to stand over night, filter on ashless paper, wash ten times vidth hot water, transfer to a small weighed porcelain crucible, char the paper, ignite, cool in a desiccator and weigh. CalciUate and record as "Total Sulphur in All Forms," using the factor 0.1374. „-snis3i„ SB eouaiajjip ^q:^ piooai puB pBjpa eno^aoe {B;o:^ JO 9SB^n90i3d dn'\ inojj suoqiBOOip^q jCxbai pnB inqdjus 93Jj jo saSB^naoaed aq^ JO rans aq:^ :;DBj:}qns 'paniuiia|ap aq o:^ aiB snoqiBoojp^fq jfxBAi naqAY j/;aBi^xa ano;aoB oiubSjo,, sb aouajajfip aq:j piooai puB 'aAOqB ;DBi:>xa auo;aoB ib:jo; jo aSB^naoiad aq^ xnojj inqd^ns aaij jo agB;nao -jad aq:^ :^DBi:jqtis 'pauraua^ap aq o:j ;on ajB snoqjBoojpXq jCsBii naq^ •;nasaid mnS laqqni pazTUBO|iiA jo :jq§iaAV jCq saSB^uaaiad sb papioaai pnB pa:^B|nDiBO Xp^Bj -Bdas aq \iev{s :^OBi:^xa anoiaoB oiubSio puB inqdpis |B:^o:^ 'inqdins aaj^ ^/aninp^ £c[ lung laqqng pazraBap^, uija; aq:^ jfq paijioads si qoiqAi ;Bq; aq n^qs :jDnpoid siqj, •^nao lad XO'O ^4 ^psaj aq; guipiooai 'pnnodnioo aq:^ jo l^ikviS ogpads aq; £({ vtmS jaqqni paztnBo^nA jo ;q§taAi Kq aSB^uaojad aq; i^dT;iTii\[ j/;q§iaAi Xq innS laqqni pazraB3|TiA„ SB aanB^Bq aq; piooai pnB ;uao jad OOX niojj ja;;Bni uSiaioj p;o; pnB sia^g ■[Biannn ';DBi;xa ano;aoB jb;o; jo saSB;uaDiad aq; jo mns aq; ;oBi;qng •swoitLvinoivo •;qSiaAV ;nB;suoD o; Sniiap ia;jB ia;;Bni a|T;BiOA-non jo agB;naoiad aq; a;BinD|BQ j/;oBi;x3 aiio;aDy„ lapnn 'aAoqB TiaAiS SB ainpaoojd puB sn;BiBddB aniBS aq; Snisn '-q ^gg puB ^g^ naaAi;aq Sm^ioq 'anijosBS q;TAi a^dniBS punoiS aq; jo noipod iubjS-^ b ;oBj;xa; ^(•X;iabjS ogpads,, sb piooai puB 'TOO'O o; 8;Bnioii30 '(OO'T stj najjB;) -q ^qS ?b ^^i'^^ ni lUBiSintni i o; qSpjW •iiB JO suiig 10 saiqqnq aAoraai o; ja;BAi japim siaSTxg aq; q;iAi Sntzaanbs pnB Smssaid 'aa;BAi q;iAi ;aAV jf^qSnoioq; naq; pnB 'jib ni raBiginim i o; qSta^i •;q'SiaAi sthbiS g nBq; ssa^ ;on sdij;s lo du;s b no not;Bniniia;ap aq; q^tsji JO noT^Buiuija^aQ *AqiABjS agpadg LIBRARY OF CONGRESS liiJIillllihilllliill 018 373 983 9 *