CIHM Microfiche Series (Monographs) ICMH Collection de microfiches (monographles) C«nadl«i liwtmito for Hlrtorlcal Mlcror»pfOductlon« / Inatttut canwilen d« m^^ 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 couleur ["/I Covers damaged / D D D D D D Couverture endommagte Covers restored and/or laminated / Couverture restaur^ et/ou pelliculie Cover title missing / Le litre de couverture manque Coloured maps / Cartes g^ographiques en couleur Coloured Ink (i.e. other than blue or black) C I I Encre de couleur (i.e. autre que bleue ou noire) □ Cotoured plates and/or illustrattons / Planches et/ou illustrattons en couleur Bound with other material / Beli^ avec d'autres documents Only edition available/ Seule ^ditton disponible Tight binding may cause shadows or distortkm ak>ng interior margin / La reliure serrn Includes supplementary material / Comprend du materiel suppl^mentaire Pages wholly or partially obscured by errata slips, tissues, etc.. have been refilmed to ensure the best possible image / Les pages totalement ou partiellement obscurcies par un feuillet d'errata. une pelure. etc.. ont M filmies 6 nouveau de fa^on i obtenir la meilleure image possible. Opposing pages with varying colouration or discolouratkins are filmed twice to ensure the best possible Image / Les pages s'opposant ayant des colorations variables ou des decolorations sont (ilm^es deux fois afin c'obtenir la meilleure image possible. Tht« Htm \\ filmtd at lh« udocilon ratio chackad b«Iow/ Ca decuiiMnt tit fnm4 au taux da rMuctlen indt^ui cl-dttseut. lOx 14x 18X 22x 26x 30x v" 19w 16x 20x 24x 28x 32x Th« copy filmed h«r« hat b««n raproduead thank* to tha ganarositv of: University of Toronto Archives Tha imagaa appearing hare are tha beit quality pouibia conaidaring the condition and legibility of the original copy and in keeping with the filming contrect apecifications. Original eopiaa in printed paper eovera are filmed beginning with the front cover and ending on the laat page with a printed or illustrated impres- sion, or the beck cover when appropriate. All 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 shell contain tha symbol — *• (meaning "CON- TINUED"), or tha symbol V (meaning "END"), whichever applies. Maps, plates, charts, etc., may be filmed et different reduction ratios. Thosa 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 «s required. Tha following diagrams illustrate the method: 1 2 3 1 2 4 5 L'Mvmplair* film« fut raproduit griea A la a*n4roait* da: University of Toronto Archives Las images suivantas ont ttt raproduitaa avac la plus grand soin, compta tenu da la condition at da la nattat« da I'axamplaira film*, at an conformity avac las conditions du contrat da filmaga. Las axamplairas orlginaux dont la eouvartura •n papier est imprim^e sent fllm>s en commencant par la premier plat at an terminent soit per ie derniire page qui comporta une empreinte d'impression ou d'illustration. soit par la second plat, salon Ie ces. Tous les autres axemplairas orlginaux sont filmte en commen9ant par la premiere page qui comporte une empreinte d'impression ou d'illustration at en 'terminent par la darniire page qui comporta une telle empreinte. Un des symboles suivsnts apparattra sur la derni*re image de cheque microfiche, selon Ie ces: Ie symbols — *> signifle "A 8UIVRE", Ie symbols ▼ signifle "FIN". Les cartes, planches, tableeux. etc.. peuvent 4tre film«s A des taux de rMuction diff«rents. Lorsque ie document est trop grand pour *tre reproduit en un seul clich*. il est film* i partir de I'angle sup*rieur gauche, de geuche * droite. et de haut en bas. an prenant la nombre d'images n*cesseire. -Les disgrammas suivants iilustrant la m*thoda. 2 3 5 6 MiOOCOPV MSOUinON TBT CHAIT (ANSI and ISO TEST CHART No. 2) y^PPUED IM/GE he teS3 CM Main SIrmt Roefcwtvr, N«w Ygrfc 14609 USA (7H) ♦Sa-MOO-PhonT^ (716) 2ae-9M9-rox MttitJe«Uti of lorottto. •'"1 \„: PAPERS PROM TUB CHEMICAL Laboratory. No. 22.-Solubility of the Sulphides of Arsenic, Antimony and Tin. BY W. R. LANG and C M. CARSON. Reprinted from the >oamal of the Society of Chemical InduHtn. Aucnst 1?, 1902. TORONTO, lfK)2. ^^mm mw- H!^|m 1^7% '^"yt J :j<^) BEPRINTED FROM THE JOURNAL of TBB SocictY of Cticmical ^nbu^try, 15 AUGUST 1902. mUBILin OF THE SULPHIDES OF ARSENIC, ANTIMONY, AND TIN. hZ W. E. LANG AHD C. M. CARBON. ♦-^sl I ^'J LONDON: EYBK AMD SrOTTIBWOODB, KABT UAKOIMO 8TBKKT, B.C. . 180S. jVSM [^Ri'priHteil from the Joitrua} of Ike Suriefp of Chfmicnl rndmtry, 15 iiiguit WYi. Ko. 13, Vol. XXI.} SOLUBILITY OF THE SULPHIDES OF AKSKNIC. ANTIMONY, AND TIN. BT W. R. LANS AND C. X. CARMON, In a former paper (thia Jonmal, Jane 16. 19«)2, T^H), an account was giren of a nhort investigution into the aoeuracy of the method! reoonimencriment8 with reference to the ■olnbility of the three aulphid s in hydrochloric acid : — I. Arsenic Sulphide in Hydrochloric Acid. — Onepramme of arsenioui oxide WHH dissolved in hydrochloric acid, iind the solution made up to 250 c.c. Into each of several tlasks 25 c.c. of the solution were measured, the arsenic precipitated as the sulphide, and filtered. (a) The precipitates were treated with equal volumes of hydrochloric acid of different concentrations and allowed to stand, at the room tempf rature, for four hours, when they were again filtered, the filtrates diluted with water, and tested by passing in hydrogen i>?lphidc. Hydrochloric Acid Water. Filtrate after passsKe of (Sp. Gr., 1 16). lI>iirojren Sulpiiide. c.c. c.c. « Slightly coloured. SO l(t .* *t 40 20 M .HO ColourlHsMi. W 40 ,, 10 «> „ 60 M (fe) The sulphides were treated with hydrochloric acid a» 'u (a), but, before Litering, hydrogen sulpiiide was passed p 3145.— 0. ■■1' iKrniNTKn fwow the journal or into cmh. Th«s filtrntes were tettei an before with h)«lroj{eu »ulphide Il.vdnMhI-iric A<-ul. Wntcr. Filtmtt' lifter pHNsnjti' of li.vilniiri'ii Siil|iliiilo. fjn. c.c. m ¥t so m rm ta 41) e ti'j Kho«eii no (■(iloiirtition. (c) Ihe sulphide* were obtained at in (a), and were afStiiD treated with hjdrochloric acid, but, instead of being allowed to stand at the room temperature, were boiled for 15 minutes. -The roiaturea were then fll'ercd, and the filtratt ■ tested. Filtrate with Hydrogcu 8ulphid«. Sulphide had almost com- pletely din^^«lv»xl. Filtrate gave precipitate with hydrogen 8ul|)hide. (rf) The procf dure was the ssire as in (c), cxctpt that, before filterinjj, the niixtnie was cooled and then ta^urattd with hjdrogen sulphide. Hydroolilorio Acid. c.c. CO. At 4'» £0 3U 3tt 5!0 4ii m Vat«r. Filtrate »hen tested with Hydrogen Sulphide. No colouration. TUE 80C1KTY Or CUEMICAL ISDt'STRT. 3 Ar»ieiu()U«iulpl.ideiii»y,t>t,Mi. betrt-atfd with hjdroclilorie ttria (np. Rr , 1 • Jfi) witlo' .bnger of ^olutlOD. if hy.lrt.neii MtlphHle be |)B^e Haturation. II. The Svluhilil!/ >/ Antimowtf Trisulphide in Hudro- rUvrir Acid.-A mAuXwu wu- uiutle coi.tuining 1 giTii. of nntiir.oity t.troxide in -^M c.c. ; 25 c.c. of the .olut.on w(rur.'d out, the antimony precipitiitei an tne .alphide, ard iho preclpitatp filtertd. The sulph.de wbk then washed into a flatk by means of 8 c.o. of com-ei.trated hjdroch''>Tic acid (-p. gr 1 • 16) being completely d.*»olvcd. but ttiv) V' an oranjje wration lo the i-olation. On addition c. another 2 c.c. aid the « lo-ralion dieappeared. The i.alph=de oi av-tlmony was again obtained by precipi- tation of a.'ic.c .t the original solution. Thia wan hittred and •'••«»oKed i r.C c.c. of concentrated hydrochloric and. Into 1 . solatloj hydrogen «ulphide wm passed con- tinuo-;iy. whilst water was added from a burette. ^^ hen 18 c.c. of water had been added, a slight colouration was visible, and when the amount of water had reached 21 c.c, the f ulphide began to precipitate. To again obtoin a clear Bolution, 8 c.c. of hydrochloric acid were nqmred. The sulphide of antimony is soluble, then, in a mixture of hydrochoric acid (Kp. gr., 1-16) and water in the pro- portion of 50 to 1«, even when hydrogen sulphide w passed in to complete saturation. IIT Stannoua Sulphide is »oluMo in hydroehlcric aiid slightly more dilute than that which is required to dissolve antimony trisr -,>hide. In order to separate the sulphide* of arsenic from tho-e of antimony and tin, the mixture shouki be treated with hydrochloric acid diluted with not more than one-third uf its volume of water, and then couioletely saturated with hvdrocen sulphde. The arsenious sulphide will be un- dissolved, and on filtering, will be loft free from antimony and tin. The precipitite may be washed with a ni.xt.ire ot h^diochloricacid and water in the proportion of .H) to 18. or with hydrochloric aeid (sp. gr., 1 -16). if hydrogen sulphide be passed into the acid before washing. This metho.:, which is substantially the same as mat given by rattin^^n atd Pattinson (this Journal, 1898, 211. •'14), was employed to estimate the arsenic in 25 c.c. of a soution containing*! grm. of aiseuuus oxidf, 1 gim. 4 THE SOCIETY Of CHEMICAL INDU8TBY. Of antimony tetroxide. and 1 grm. of tin oxide in 250 c.c The sulphide of arseuic, after separation, was dissolved in nitric acid, the anenic precipitated by magnesia mixture, and weighed as magnesium pyro-arsemate :— In qualitative work, the solution of the sulphides in yellow ammonium iulphide may first be precipitated by dilute hydrochloric acid. The mixture of sulphides, on being filtered and washed, may then be separated as described alwve. This is preferable to the method of pouring the solution into concentrated hydrochlorie acid. ►••-<- tls