THE AN'ALYBT. 119 Q" THE ACTION OF OOLD CONCEN2RATED Bm;pfflTRIa iWID ON &FAD AND IT8 AGLOYB. BY Lums PI^. UNTIL qdte recenfly it has been regazded as h o s t indisputable that the purer the lead, the less action would sulphrjuic wid have upon it. In opposition to this idea, 8 very intoresting paper W ~ R presented by Mi.. James Napier, before Om Gllaagow Philosophical Sooiety, a full report of whit& can be found in the Cfienzt'caZ 2vscaS for December, 1880. Briefly abstracted it is as follows : Sulphuric acid was shipped in cases of dleetlead, of which oither bulged badly or burst. To arscerfain the cause of tbia d o n , the The wid was of sp. gr. 1,842 and the following composition, €&,S0499a78--80~0*02 The lead ~ 8 s of extraordinary purity, containing according to the a d y ~ 3 Pb.99.96 -CU. 0.04. The gas evolvcd was pure hydrogen. Errposing a known surface of the lead to the action of oold concenhted anlphulic acid, gas was given off equivdent to 42 cubic inches per square foot lead exposed. Another samplo from a concentrating pan (No 1) of the 8-e composition gave under similar circumstmces, 16 cubic inches per square foot. A seeond sample of l a d (NO. 2) having a composition of Pb, 99*60 Cu. 0.08. Sb. 0.42 yielded only 6 cubic inch per square foot. AS a basis for further experiments, Xr. Napier tooka soft lead not mdysed, d d w to NO. 1, which, averaging several determinations, yielded 9 4 cubic inches per square foot. CIdling this lead No. 8, the foIlowing alloys were made and yielded the fonowing amounts o€ gas by the action of sulphuric acid.acid, the lead, and the gas musing the pressure were analyzed. --P~SO,O*I~~U~SO~O*O~. ma Load NO, 3, 99'64 ou. h b . zn. '37 I The paper wa8 discussed by the Booiety, and the Prosident in summing up, said fie following points appeared proven : 1. Uhemicdy pure load was unsuitable for sulphuric wid evaporating pans. 2. Lead containing certain impu<ties, tlgd especially zinc, wm unsuitabk~ 3. Antimony seemed to render &Q lead more durable. 4. The mbject required further investigation. It is to this investigation that the remainder of this paper will be devoted,1 a0 THE ANUYST, - __ -~ The lead taken as a ‘bat& for the alloyrs which I have experimented upon, was a chemica;lly pure lead made by Merok, of Darmstadt, and guaranteed by him.Themethod employed differed from that made use of by Napier, who measured the gas evolved from a known surface of lead. In the followling experimentg, the action of the dphuric acid was measured by the momt of lead or doy converted into sulphate, which waa ascertained by weighing the alloy beforo immersing in Sulphnric acid, and after the action, Cleansing from any adhering sulphate and reweighing. In a l l forty (40) samples of lead and alloys of known composition were acted upon by the acid and the action measured. In some cases the results may appear anomalow, but; not more so than the case reported by Napier, in which lead of the same composi- tion gave off under similar circumstances, in one ease 41 cubic inches per squase foot, in the other only 16 cubic inches.In the making of the alloys, great care was taken to obtain as homogenous a mixture as possible, and in order to avoid oxidation, the fusion was performed under a layer of powdered chmcoal. The making of 40 alloys was thus by far the most tedious part of the investigation. The alloys experimented upon were those of lead with antimony, tin, biamuth, cad- mium, silver and Zinc. After the preparation of the aUays, they were carefully rolled to about the same thickness, and the same surfam exposed in each case to the action of the same amount of acid for a like time. me mrhce exposed was 2 sq. in., and the amount of acid used 10 C.C. The action was allowed to proceed 24 hours at a, temperature of 2OOC. me acid employed was 0. P. sulphuric add of sp.gr. 1,825. In the tables the h t co1nm.n gives composition of alloys j the second, the loss of lead per sq. foot of surface exposed, the weight being in grammes; the third, the amount of gas evolved calmdated from the quantity of lead converted into the sulphate. 1 c. P. Lead. 1’296 gnns. 9 ou. in, 2 9 s 2-088 ), 14.5 ,, 3 9 ) 2.952 ,, 20-5 ,, 4 9 ) 2.282 ,, 16-5 ,, Average loas €or pure lead, 2.160 grrm3. per sq. ft. Average gm evolved from sq. ft., 15 cu. in. In all caseB quite a vigorous evolution of hydrogen took place at the instant of immersion, while in an hour scarcely any action was percepiible. It will be noticed that the quantity of hydrogen evolved agrees quite closely with the amount given off by lead in Mr. Napier’s experiments. In the case of the alloys, however, I did not find that the addition of foreign metals produced such a change in the amount of lead converted into sulphate, as tho following figures will &ow.THE ANALYST.121 ~mputing the amount of w, the loss is odculated for convenience as entirely lead. AXTIXOXY ALLOYS. h Pb. 100 Sb. 0-B p& 1.872gme. 13 on. in. 8 s? 1 t t 2'016 99 14 3, 7 I, 2 9, 2.016 9 , 14 9 , 8 Y9 3 9 , 1.612 ¶ ¶ 10 ?, 9 Y9 6 ,y 1.584 Y Y 11 9 , 10 ,y 10 ,, 1-684 ,, 11 ,, It will be seen from Me, that under tihe conditiom of the experiment, the antimony did not seem to d e o t the lead to moh a degree as in Mr. Napier's researches, although retarding the adion of the acid. It ahows, however, what a laxge tamount of antimony may be present without &@ding the solubility of the lead.TIN rn0YS. I1 12 Y ¶ 1 )) 3.744 9 ) 26 ¶ Y 13 ,? 2 ,, 3-080 ,, 22 ,, 14 Y Y 3 ,, 2962 ,, 21 ,, 16 Y, 5 as 3'232 9s 23 83 16 9Y 10 ¶ 9 2.380 Y, 17 3 , Pb. 100 Sn. 0.5 parts 2.802 gms. 19 OR. in. In the case of the alloys with tin, the aotion is in a,ll oasefi augmented, but does not mem to increase in proportion to the amount of tin present* BIWXH ALLOY#. 17 Pb. 100 Bi. 0.5 pads 1*800 gms. 12 cn. in. 18 y, 1 y, 4-032 9, 28 ¶, 19 ,, 2 1 ) 1.656 9 9 11 ,, 20 99 3 9, 1.m ,I 12 9 , 21 9, 5 I, 2.232 99 16 ¶ 9 22 *, 10 ,, 3.600 ,) 25 s y The figures in number IS are evidently anomalow, and probably were the result of m imperfeot admixture or separation of the Bi. and Pb. If they are disregded we would have the general action of bhuth in the alloyB with lead a~ retarding in guanti- ties less than 5 per cent,, and above that figurehastening the formation of lead sulphate.U A D m AmOYS. 23. Pb. 1OOCd. 0*5partS 1*728p. 12cu. in. 24. 99 1 1, 1 W 6 ,y 11 9) 25. 3, 2 a, 1.296 Y Y 9 Y9 26. Y Y 3 ), ~ 7 2 a ,) 12 ,, 27. 'Y 6 9s 1.296 9 9 9 9) 28. 9 ) 10 $9 3'628 9s 24 )S Inregardto cadmium we have it demwkg tihe solubiK@ of leadtoa greater extent even thm antimony, while above 5 per cent. it raises its solubility. BrLvEIt dIitOY8. 29. Pb. 30. 31. 32. 33. 34. 1.684 gme. 1'128 3, 1.944 ,, 1.684 ,, 2.016 ,, 2448 ,,122 THE ANALYST. Silver seem to exert very little Muence, in m a l l proportion, slightly deorecldng the action, in large proportion dightly bmeasing the solubility. m u bIsroyLI. 35. Pb. 1 O O Z n . 0.6 park, 2-664gms. 18 m. in. 30. ,? 1 ,, 2.304 ,, 16 ,, 37. 9) 2 ,, 3.816 ,, 26 ,, 40. 19 10 ,, 4.392 ,, 30 ,) 88. 9 ) 8 ,$ 2.664 ,, 18 ,, 39. 9, 6 ,, 4.032 ,, 28 ,$ The aolubilifies of the alloys of lead and Zino are thus greater than those of lead with any other metal experimented upon. To 6- up &e redts of the work, it appeam : 1. The metals, antimony, bismuth, ctadmium, and &her in mall qumtitieir, proteot lead from the action of the cold sulphurio add ; while in proportions above 3 per cent., they all, with the exception of antimony, hcrease the solubility. 2. Antimony, when preaent even to the amount of 10 per cent,, deoretlscs the eolubdity of the lead. 3. !En and zinc doys are more affected than pure lead.-JomZ c$ t b Afim*cm Czt#?&d 80&*.