CIHM Microfiche Series (IMonographs) ICMH Collection de microfiches (monographies) Canadian Instituta for Hiatoricai Microraproductiona / Inatitut Canadian da microraprodiictiona hiatoriquaa Technical and Bibliographic Notes / Notes techniques et bibliographiques The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming are checked below. Coloured covers / Couverture de couteur Covers damaged / Couverture endomnug^e □ Covers restored and/or laminated / Couverture restaur^e et/ou pelliculde Cover title missing / Le litre de couver < " - ? ^ je Coloured maps / Cartes g^ographiques e c our I — I Coloured ink (i.e. other than blue or black) C I I Cotoured plates and/or illustrattons / Encre de couleur (i.e. autre que bleue ou noire) Cotoured plates and/or illustrattons / Planches et/ou illustrations en couleur D D D n D Bound with other material / Reli6 avec d'autres documents Only editton available / Seule ^ditton disponible Tight tending may cause shadows or distortion atong interior margin / La reliure serrie peut causer de i'ombre ou de la distorston le long de la nriarge intirieure. Blank leaves added during restorations may appear within the text. Whenever possit>le, these have been omitted from filming / Use peut que certaines pages blanches ajoutees lors d'une restauration apparaissent dans le texte, mais, lorsque cela ^tait possible, ces pages n'ont pas k\k filmies. Addittonal comments / Commentaires suppl^mentaires: L'Institut a microfilm^ le meitleur exemplaire qu'il lui a iXh possible de se procurer. Les details de cet exem- plaire qui sont peut-4tre unk]ues du point de vue bibli- ographique. qui peuvent nf)odifier une inuige reproduite, ou qui peuvent exiger une modification dans la metho- ds normale de filmage sont indiquis cl-dessous. j j Coloured pages / Pages de couleur I I Pages damaged / Pages endommag^es D Pages restored and/or laminated / Pages restaurtes et/ou pellicul^es Pages discotoured, stained or foxed / Pages d^color^es, tachet^es ou piqu#es I I Pages detached / Pages d^tach^es \y\ Showthrough/ Transparence rri Quality of print varies / D D D Quality in^gale de I'impression Includes supplementary material / Comprend du materiel suppl^menlaire Pages wholly or pariially obscured by errata slips, tissues, etc., have been refilmed to ensure the best possible image / Les pages totalement ou partiellement obscurcies par un feuiilet d'errata, une peture, etc., ont k\b filmies & nouveau de fa^on & obtenir la meilleure image possible. Opposing pages with varying colouration or discolourations are filmed twice to ensure the best possible image / Les pages s'opposant ayant des colorations variables ou des decolorations sont liimees deux fois afin d'obtenir la meilleure image possible. Thit Ittm t> f ilmtd %\ ih« rtducllon ratio ehcektd btlow / C« deeumtnt tst film< au taux da rMucllon tndlqui ci-dtisouf. lOx 14x 18x 22x 26x 30x \/ 1 12x 16x 20x 24 x 28x 32x Th« copy filmad h«r« hM b««n r«produe«d thanks to tho gonorotity of: University of Toronto Archives The images appearing here are the best quality possible considering the condition and legibility of the original copy and in keeping with the filming contract specifications. Original copies in printed paper covers are filmed beginning with the front cover end ending on the last page with a printed or illustrated impres- sion, or the beck cover when appropriate. Ail other original copies are filmed beginning on the first page with a printed or illustrated impres- sion, and ending on the last page with a printed or illustrated impression. The last recorded frame on each microfiche shall contain the symbol — »■ (meaning "CON- TINUED"), or the symbol ▼ (meaning "END"), whichever applies. Maps, plates, charts, etc.. mey be filmed at different reduction ratios. Those too large to be entirely included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as many frames ds required. The following diagrams illustrate the method: 1 2 3 1 2 4 5 L'«x«mplair« film4 fut raproduit gric* A ia g*n*ro«lti d«: University of Toronto Archives Let images suivantes ont it* reproduites avec le plus grand toin, compte tenu de la condition at de la nettet* da I'exemplaire film*, at an conformit* avac las conditions du contrat de filmage. Lea axempiairas origlnaux dont la couverture en papier est imprlm*e sent fllm4s en commen9ant par la premier plat at en tarminant soit par ia dernitre page qui comporte une empreinte d'impression ou d'illustration, soit par ia second plat, salon la cas. Tous las autres exemplaires origlnaux sont filmte an commandant par la premiire page qui comporte une emprrinte d'impression ou d'illustration at en'terminant par la darniire page qui comporte une telle empreinte. Un des symboies suivants apperattra sur la dernitre image de cheque microfiche, seion le cas: !s symbole — »> signifie "A 8UIVRE", le symbols ▼ signifie "FIN". Les csrtes, pisnches. tableaux, etc.. peuvent *tre filmte i dec taux de reduction diffArents. Lorsque le document est trop grand pour Atra reproduit en un seui clichA, 11 est film* A pertir de I'snglr supArieur gauche, de gauche A droite, et de haut an bas. en prenant la nombre d'images nAcessaire. 'Lea diagrammas suivants iilustrent la mAthode. 2 3 5 6 Miaooopv MWumoN mr OMtr (ANSI and ISO TEST CHART No. 2) /f=»PLB3 IK/MGE he l«U CMt IMn StrMi nnttmUm. Ntw York 1M09 USA (71i) 4S2 - 0300 - Phom (71^ 2M - saw - Fax SniDersUt) of f oronlo. PAPERS FROM THE CHEMICAL LABORATORY. No. 21.— The Separation of Arsenic, Tin and Antimony. BY W. R. LANG, C. M. CARSON and J. C. MACKINTOSH. Rctirintod from the Jotirnal of the Society of rhcmlcol Ittdnstry. jnae I*). l«02. TORONTO, 1902. SEPBINTSD FROM THE JOUBNAL 09 SocictY of £t}emtcal Onbustry, 16 JUNE 1902. THE SEPARATIOII OF MSENiO, TM, AND ANTtlONY. n W. S. LAKG. D.Sa. 0. M. OJLRSON, BX. avd J. C. MACKINTOSH. LOMDONi XTBB AXO SrOnUWOOOB^ MAtrg OASDUIO •!■■■*, a.0. 1902. r ■ f* ■» . \ ■ ■» l"".-^'- f'^: rj--: - 11 - -t4 ;,•■.'■■ r:5 ' . - '■'^. ' ■ .V--"1 ^"'™T°'^^ T REPRINTED FROM THE JOURNAL OV THIS Society of Clicinical On^ustvY, 10 J UN'' IlHVi. ".r»'X«/>.»/X/^ THE SEPARATION OF ARSENiG, TIN, ANl ftiCNY. BT VV. B. LANG. DSo, C. M. CARSOX, li.A., J. C. MACKINTOSH. »'VX^*V«%*vXX*V*V^N^\X*^V'< LONDON: E¥KK AND SrOTTlSWOUUK, BAST UAUDIHO ITKKKT, 1I.U 1902. lRfprinM/rom the Janmal of thf fltteift^ of Chemicnl Indmiirt, lA •/««•<■ 1001 So. 11, Vol. SXT.} THK SSPAIIATION OF AHS NIC, TIN. AND ANTIMONY. BT W. B. LANO. P.iC, C. M. CAB80N, B.4., AND J. C. MACKirTOSU. ThcM experiments were uncjftakeD to determine on a 8uit»hie method for uccurately estimating the amounttt of arsenic, antimony, and tin in a mixture. VariouK pmceiuNss were tried an recommended in differi-nt tuxt-bookn on ({uulitatire analyHis, all uf which had proved, in the nuiliora* opinion, more or lost anvatihfactory. I.— The principlfs involved in the first method de»ii*ed were the oxidation of the arfenic sulphide to aracuic ueid, and the siibsequent separutiun of the autimony sulphide from that of tin hy dif^estion with tartaric acid. Tlu ]r<>- cess was thus carried out : — Known quantities ol pun- arcenic acid, tin chloride, anil tartar emetic, were diBSoi\ <'d in water, with addition of sufficient hydrochloric acid (arsenic free) for complete solutiou. The whole was made up to a known volume, and aliquot parts taken for subse- quent experiments. After reduction with sulphur dioxide the elements were precipitated as sulphides with sulphuretted hydrogen. It was found that precipitation occurred bcs: in hot solution, not too strongly acid. The washed precipi- tates were evaporated to dryness with 15 c.c. of concentrated nitric add, and the arsenic acid extracted by tiigestion io the water-bath with 100 c.c. of water. In the resulting filtrate, the arsenic was determined as IMg-.-Xs-jO;. For the antimony, the residue from the last filtration was digested with a concentrated solution of tartaric acid for one hour, then filtered, and the residue washwl, ignited, and weighed as SnOj. To the solution of antimony oxide in tartaric acid were added hydro«'liloric acid and a considerable excess of water, and the antimony then precipitated as sulphide. Oxidation with nitric acid and subsequent ignition brought it into the sti.t J of oxide (SbjO^), iu which it was finally weighed. Our results were as follow : — For each experiment, 20 c.c. of a solution were employed containing O-O80O grm. of AsjOj, 0-0800 grm. of SnCl^, and 0-0731 grm. of SlijO^, p 4805.— 7. THE 80C1KTY OF CUEMICAL IMDUSTUT. aiid the amounts of arsenic, tin, and antimony found were Ciilculitted to the above. 8 b/), . Gim. 0-OHo* 0-11732 11. Orm. 07l»7 072i AveraRC. Grtr. 0-(l8(M, O'OSitl 0-0727 The dii^estion of the mixed oxides of antimony and tin is best earned on in a flask, with a glass tube and cork attaclied to prevent evaporation, sunk in a water bath. J I— The method here employed was to separate the sulphides of antimony and tiu by means of concentrated hydrochloric acid. The results of several experiments showed that an appreciable quantity of arsenious sulphide was dissolved by the hydrochloric acid when warme«l, though the method of separation is advocated in most text- books. In this Journal, 1898, 211—214, Messrs. J. & H. S. Puttiuson showed that the addition of two-sevenths by volume of hydrogen sulphide water sufficed to prevent the solution ofany of the arsenious sulphide, whilst the sulphides of antimony and tin dissolved readily. Nothing is said of the temperature at which this reaction took plaeo. We have tried the effect of different coucentratiims of hydro- chloric acid alone at different temperatures, and found the amounts of anenious sulphide, which are dissolved, to vary very considerably. It is our intention to iuvestipate the solubility of sulphide of arsenic under varying conditions of temperature, concentration, and relative masses of sulphide Hud acid ; but as far as our present examination has gone, these results point to the method of separating the sulphides by hj drochioric acid as being unreliable. 'J!>^»^m^afimMBti»msxeiaBss^mimmsam% Siiii