ll. t. Ch. (0 17 E GEESIS O EECOGAIMEY hn . St, Unvrt f Cnntt In his Wolcott Gibbs Memorial Lecture,Frank W. Clarke, who had studied under G ibbs from 1865 to 1869, commented on the advances in analytical chemistry made by Gibbs and his students at the Lawrence Scientific School (1): t th t prtnt f ll th ltrlt dtrntn f ppr, n nvrll d, hh frt pblhd fr Gbb lbrtr. It tr tht Grn ht, , ld t hv d th thd h rlr, bt fr I n dvr, h fld t pblh t. Gbb, thrfr, nttld t fll rdt fr pr hh th prntr f n thr. As discussed later, C. Luckow published this claim soon after the appearance of Gibbs account. A paper that marks the centenary of Gibbs' work on electrogravimetry does not men- tion Luckow, who may have originated the technique (2). Olvr Wltt Gbb Oliver Wolcott Gibbs (1822-1908) - he dropped the first name, Oliver, early in his career - was a scientist of wide were attributed to over-rapid deposition, resulting in a spongy interests (1). Apart from his contributions to analytical chem- deposit. This is difficult to wash free from impurities and also istry, his work on the ammonia-cobalt compounds and on oxidizes easily. phosphotungstic and other complex inorganic acids occupied Two points made by Gibbs were that, after removal of much of his career. He was very much a person-to-person copper, the solution contained any other constituents of the teacher, keeping in close touch with his comparatively few sample and that it was at least probable that nickel might be students. determined by electrolysis of an ammoniacal solution of its Results obtained by E. V. M'Candless, presumably one of sulfate. In two determinations of nickel in a commercial Gibbs' students, form the basis of the 1864 announcement of sample, M'Candless obtained results of 91.36% and 91.60%. the technique that later became known as electrogravimetry. The metal deposit was bright and coherent, thus upholding Actually, the very brief announcement, "On the Electrolytic Gibbs' prediction. What a pity that no nickel determinations Precipitation of Copper and Nickel as a Method of Analysis", were reported for the copper-free liquid from the coinage alloy is the sixth and final section (pp. 334-36) of Gibbs' paper, experiments! Then we should have had the first example of an which carries the general title "Contributions to Chemistry overall electrogravimetric analysis of a sample. from the Laboratory of the Lawrence Scientific School" (3). In 1865, C. Luckow, a chemist working for the Cologne- The other sections deal with purely chemical separations, such Mindener Railway, claimed that he had been determining as of chromium, manganese, cobalt, and uranium from various copper and silver by electrolysis since 1860 (4,. In view of other metals. subsequent events, there is no reason to doubt his claim. He The deposition of copper from solutions of the sulfate was entered his methodology in a competition organized by the carried out in a small platinum capsule connected to the nega- Mansfeld Ober-berg und Haien Direction in Eisleben. This tive pole of one or two Bunsen cells. The positive electrode company needed a rapid and reasonably accurate method for was a stout platinum wire that dipped centrally into the solu- the determination of copper in ores, etc. The prize went to a Dr. tion. Completion of deposition, taking one to three hours, was A. Steinbeck for a method that involved titration in ammonia- checked by testing a drop of the liquid with hydrogen sulfide cal medium with potassium cyanide as a final step. However, water. After washing and vacuum-drying over sulfuric acid, Luckow also received an award. The details of both methods the copper-carrying capsule was reweighed. Six results with were published by the company in 1869 (6). Originally an average close to the theoretical value and a standard devia- Luckow, like Gibbs, had used the rather slow deposition from tion of about 0.3% are quoted. sulfate medium; otherwise he might have won the competition. M'Candless then determined copper in copper-nickel coin- Progress by Luckow and by others soon increased the speed age alloy. Four of his results were within 0.05% of the and versatility of electrogravimetry. specified 87.50% of copper. Some abnormally high results Two major advances made by Luckow were his discovery 8 ll. t. Ch. (0 that deposition of copper from dilute nitric acid medium was determination of nickel (9-12), copper (9,10,12), cobalt advantageous and his introduction of a separate cathode, i.e., (9,10,12), lead, zinc and manganese (11), and mercury (13). one that was not also the solution container. He used a platinum This last determination was described by Frank W. Clarke, the foil that was about 2-1/2 in. long and 1-1/4 in. wide. This was author of the Gibbs Memorial Lecture (1). bent into a cylinder and a stout platinum wire was attached. The Some of the later developments that extended the scope and anode, a flat platinum wire spiral of diameter to fit into the speed of electrogravimetry have recendy been reviewed (14 ,15). bottom electrolysis beaker, had a vertical extension to carry a One of these was the mercury cathode, developed by Edgar binding post, and a stand with an arm carrying a screw Fahs Smith and his students (14). The publication of Smith's connector held the cathode with its lower edge close to the book in 1890 (16) evoked a short note from Gibbs (17). This anode. concerns a paper that Gibbs had read before the National Luckow also examined the electrolytic behavior of a number Academy of Sciences in 1885. The note states that the of other metals, especially those likely to accompany copper in experiments that he made on metal deposition on a mercury technical samples (6). By suitable adjustment of the medium, cathode were purely qualitative, and that Luckow subse- he achieved simultaneous deposition of copper on the cathode quently applied the same process to the estimation of zinc (18). and lead, as lead dioxide, on the anode. Three years after the first communication from the Eisleben frn nd t laboratories, another described some developments, including an improved platinum electrode system (7). The cathode, now . W. Clr, "Wltt Gbb Mrl tr", Trans. of conical form, was slotted, so that oxygen arising from the Chem. Soc., 0, 95, 22. anode could pass to the exterior of the cathode. In a sense, this 2. Szbdvr, "Wltt Gbb nd th Cntnr f was the ancestor of the gauze-type electrodes that permit free Eltrrvtr", J. Chem, Educ., 64, 41, 66666. circulation of the solution. The actual aim was, however, to . W. Gbb, "tr zr Ch d brtr dr overcome a problem that occurred in the analysis of copper rn Sntf Shl", . Anal. Chem., 864, , 26 samples that contained much iron. With a simple cylindrical Amer. J. Set. Arts, 86, 89, 86. cathode a dark coloration, caused by reduction of iron along 4. C. , "Ubr EltrMtllAnl", Dinglers with the copper, appeared in the oxygen-starved region around Polytech. J., 86, 177, 22, 2602. the outside of the cathode. By the summer of 1869, the . Szbdvr, History of Analytical Chemistry; rn: laboratory was able to determine copper in all samples that Yr, 66, p. 4. were free from antimony, arsenic and bismuth, which precipi- 6. Mnfldhn Obrbr nd ttn rtn n El tate on the copper deposit arid blacken it. bn, "Ubr tn d Kpfrhlt Shfrn nh In 1880, Luckow wrote a partially-reminiscent paper con- prrtn Mthdn", . Anal. Chem., 86, 8, 4 th ltr cerning the use of the electric current in analytical chemistry r t tn bn n p. 2. (8). He recalled the accounts that he had published in 1865 (4) . Mnfldhn Obrbr nd lttn rtn n El and pointed out the advantages of electrodeposition. One of bn, "Ubr d tn d Kpfr nd nr ndrr Mtll these was that the process can run unattended, e.g., overnight. f ltrlth W", . Anal. Chem., 82, 11, 6. Following a survey of the electrochemical behavior of solu- 8. C. , "Ubr d Anndn d ltrhn Str tions of various acids and salts, Luckow referred to some of the n dr nlthn Ch", . Anal, Chem., 880, 19, . then recent investigations by others. Examples included the . Wrhtn, "tr zr ntttvn tn dr Mtll f Eltrlth W", . Anal. Chem., 86, 15, 2 06. 0. G. Shdr, "r ltrlthntn d l nd Kblt", Berg-u.-Hiittenmann. Z., 8, 6, , , td n . rn, . Anal. Chem., 8, 16, 440. A. h, "r ltrlthn trnn d Mnn, l, n nd l", Compt. Rend., 8, 85, 22622. 2. W. Ohl, " ltrlth tn vn Kblt, l, Kpfr nd drn rthl n dr nlthn Ch", Z. Anal. Chem., 8, 18, 2. W. Clr, "r ltrlth trnn d Q lbr nd d Cd", Amer, J. Sci. Arts, 88, 16, 20020. 4. M. bnn, "rrn fr Indtr: Edr h Sth ttn And nd blCp Mrr Cthd", n . ltrd rrnnt fr ltrdptn St nd M. Orn, d., Electrochemistry, Past and Present, Bull. Hist, Chem. 7 (1990) 19 Arn Chl St: Whntn, .C.,8, pp. 48468. St, "nr I. S. Snd (844, A Wll brd tr", n . St nd M. Orn, d., Eltrhtr, t nd rnt, Arn Chl St: Whntn, .C., 8, pp. 4646. 6. E. Sth, Eltrhl Anl, hldlph, 80. W. Gbb, "t n th Eltrlt trntn f Mtl Al", Ar. Ch. ., 82, , 0. 8. C. , Ch. t. 88, , 8 td n E. ntz, . Anl. Ch., 1886, 2, 4.