WOLLASTON, WILLIAM HYDE, M.D. 



WOLL ASTON, WILLIAM HYDE, M.D. 



796 



the ammonio-muriate of platinum (in more modern chemical language, 

 the double chloride of ammonium and platinum) BO obtained, and its 

 heating, with the utmost caution, and with so low a heat as just to 

 expel the whole of the elements of the sal-ammoniac, and to occasion 

 the particles of platinum to cohere as little as possible ; for on this 

 depends the ultimate ductility of the metal. In the next place, the 

 resulting gray product of platinum is to be rubbed to powder or 

 ground, well washed and diffused in water, and allowed to subside into 

 a uniform mud or pulp, which is to be transferred to a brass mould, 

 and subjected in that to forcible compression. Finally, the cake of plati- 

 num thus produced, is to be exposed to khe most intense heat that a 

 wind- furnace (in Dr. WoUaston's time) could be made to receive, and 

 struck, while hot, with a heavy hammer, so as at oue heating effec- 

 tually to close the metal, or weld the particles into a solid mass 

 which may then be forged into an ingot and subsequently subjected 

 to any process of manufacture. 



The first introduction of the continued mechanical pressure of the 

 reduced platinum before it is heated for the purpose of welding it 

 together, as an essential part of the process for obtaining the metal in 

 a malleable state, was claimed in private, by the late Mr. Thomas 

 Cock, a practical metallurgist, and a member of the British Miueralo- 

 gical Society, noticed in a former article [PEPYS, W. H.] with Mr. 

 Pepys, Messrs. A. and C. R. Aikin, Dr. Babiugton, Mr. R. Phillips, and 

 other chemists and mineralogists. He also affirms that it was origin- 

 ally proposed by him to Dr. Wollaston, who effected by a lever-press 

 of peculiar construction, which he devised for the purpose (and 

 described in the Bakerian lecture for 1829) what Mr. Cock, according 

 to his own statement and to an account of the process communicated 

 by him to Messrs. Aikin's ' Chemical Dictionary,' had previously 

 effected by a screw-press. 



The welding together of the platinum without the addition of any 

 other metal or substance, stated by Leopold Gmelin in his ' Handbook 

 of Chemistry ' to characterise Dr. Wollaston's method as distinguished 

 from the inadequate processes before adopted for obtaining it in a 

 malleable state, is common to the processes of the late Mr. Richard 

 Knight (also a member of the British Mineralogical Society, and after- 

 wards F.G.S.) Mr. Cock and Dr. Wollaston, and was probably first 

 employed by Mr. Knight. It certainly belongs to English chemists 

 of the beginning of the present century. In Dr. Wollaston's hands 

 however every part of the process received the impress of the peculiar 

 combination of comprehensive views with minute accuracy in par- 

 ticulars by which he was distinguished. He made it his own 

 in the most undeniable manner, and all the preceding methods have 

 been entirely superseded by his. Every student of chemistry, and 

 every practical chemist may profitably study the Bakerian lecture as a 

 model of the application of Chemistry and Physics by an operator 

 extensively and accurately versed in both, to effect a single object of 

 great importance. 



It is right to say, in conclusion of this subject, that Dr. Wollaston 

 did not claim the invention of the method which he practised ; be 

 simply stated as the reason for describing it, that, from long experience, 

 be was better acquainted with the treatment of platinum, so as to 

 render it perfectly malleable, than any other member of the Royal 

 Society. But of some of the most refined, philosophically conceived, 

 and efficacious portions of it, he was undoubtedly the originator. 

 The late Dr. Thomas Thomson, F.R.S., the author of the celebrated 

 ' System of Chemistry,' and Regius Professor of that science in the 

 University of Glasgow, remarks in his ' History of Chemistry ' (form- 

 ing part of the ' National Library,' of which a few volumes appeared), 

 that it was Dr. Wollaston who first succeeded in reducing platinum 

 " into ingots in a state of purity, and fit for every kind of use :" that 

 " it was employed, in consequence, for making vessels for chemical 

 purposes ; " and that " it is to its introduction that we are to ascribe 

 the present accuracy of chemical investigations. It has been gradually 

 introduced," he continues, " into the sulphuric acid manufactories, as 

 a substitute for glass retorts." 



The use of platinum vessels for the final concentration of sulphuric 

 acid by distillation, had been practised on a small scale by a manu- 

 facturing chemist named Sandman, a member of the British Mineralo- 

 gical Society ; but Mr. Richard Farmer was the first sulphuric acid 

 maker who adopted it, and this he did on the large scale, at his 

 works, still carried on by his near connection Mr. Edward Probart, on 

 Kennington Common, London. In 1809 he engaged Dr. Wollaston to 

 superintend the construction for the purpose of a large vessel of his 

 own platinum, weighing 322oz. troy, at the cost of 300?. ; and this 

 proving of the anticipated advantage, two other vessels were con- 

 structed in the course of the following six years, having the aggregate 

 weight of 828 oz.,and costing together 685?. Dr. Wollaston afterwards 

 constructed similar largo vessels of platinum, for other makers and 

 rectifiers of sulphuric acid. From his correspondence with Mr. 

 Farmer, which we have been kindly permitted to examine, it appears 

 that the method of transacting business pursued by Dr. Wollaston in 

 such cases, was to charge per oz. for the platinum he supplied, and 

 of which metal indeed he was for many years, nearly throughout his 

 life, the sole manufacturer and in addition, the actual sums dis- 

 bursed in payment of workmen, for the fabrication of the vessels, 

 but not to receive any remuneration for his own superintendence, 

 which however was of the most effective description. When ho pro- 



posed to manufacturers or tradesmen improvements in chemical 

 processes, or in the construction of instruments or apparatus, he con- 

 tracted to receive nothing, if they should prove unsuccessful, but to 

 be paid a certain proportion of the savings or profits, in the event of 

 their succeeding. In making a profitable business of practical science, 

 he thus never abandoned the character of. a professional man and a 

 master-manufacturer, but always maintained the position of a 

 gentleman. 



In giving a biographical sketch of Dr. Wollaston, it will be proper 

 to allude more particularly to some of the memoirs which he contri- 

 buted to the Transactions of the Royal Society : we cannot, we believe, 

 more effectually perform this duty than by quoting what has been, 

 said of his varied labours by his contemporaries and friends Mr. 

 Brando and Dr. Thomson. The former remarks that the promul- 

 gation of the theory of definite proportions " in this country is chiefly 

 to be attributed to Dr. Wollaston, whose admirable suggestion of a 

 synoptic scale of chemical equivalents was brought before the Royal 

 Society in November 1813. Many years previous to this he had 

 established tho important doctrine of multiple proportions, in a paper 

 ' On Super-acid and Sub-acid Salts,' printed in the ' Philosophical 

 Transactions' for the jear 1808 : he now showed the important prac- 

 tical applications of which the theory was susceptible, and by con- 

 necting the scale of equivalents with Gunter's sliding rule, has put 

 into the hands of the chemist an instrument infinite in its uses, and 

 equally essential to the student, the adept, and the manufacturer." 



" Dr. Wollaston's first contribution to the Transactions of the Royal 

 Society was in June 1797, being an essay 'On Gouty and Urinary 

 Concretions,' in which he made known several new compounds con- 

 nected with the production of those maladies, in addition to the uric 

 combinations previously discovered by Scheele : these were, phosphate 

 of lime ; ammonio-magnesian phosphate, a mixture of the two form- 

 ing the fusible calculus; oxalate of lime; and more lately he added 

 cystic oxide to the list of his previous discoveries. (' Phil. Trans.,' 

 1810.) In 1804 and 1805 he made known palladium and rhodium, 

 two new metals contained in the ore of platinum, and associated with 

 osmium and iridium, discovered about the same time by Tennaut. In 

 1809 he showed that the supposed new metal tantalum was identical 

 with columbium, previously discovered by Hatchett, and shortly 

 before his death he transmitted to the Royal Society the Bakerian 

 lecture, in which he fully describes his ingenious method of rendering 

 platinum malleable." (' Manual of Chemistry,' 6th edition, 1848, vol. 

 i., p. cii.). 



In his ' History of Chemistry,' as cited above (vol. ii., p. 248), Dr. 

 Thomson remarks : " Dr. Wollaston had a particular turn for con- 

 triving pieces of apparatus for scientific purposes. His reflective 

 goniometer was a most valuable present to mineralogists, and it is by 

 its means that crystallography has acquired the great degree of per- 

 fection which it has recently exhibited. He contrived a very simple 

 apparatus for ascertaining the power of various bodies to reflect light. 

 His camera lucida furnished those who were ignorant of drawing with 

 a convenient method of delineating natural objects. His periscopic 

 glasses must have been found useful, for they sold rather extensively ; 

 and his sliding rule for chemical equivalents furnished a ready method 

 for calculating the proportions of one substance necessary to decom- 

 pose a given weight of another. Dr. Wollaston's knowledge was more 

 varied and his taste less exclusive than any other philosopher of' his 

 time, except Mr. Cavendish ; but optics and chemistry are the two 

 sciences which lie under the greatest obligations to him. To him we 

 owe the first demonstration of the identity of galvanism and common 

 electricity ; and the first explanation of the cause of the different 

 phenomena exhibited by galvanic and common electricity." 



We may add to the above, that Sir John Herschel has stated that 

 Dr. Wollaston was the first to introduce into instrumental practice, in 

 his goniometer, the direction of a reflected ray of light, as the indi- 

 cation of the angular position of a surface too delicate for handling 

 a method afterwards proposed by Mr. Babbage and employed by < iau>s 

 for other purposes. The use of this instrument by English mineralo- 

 gists has already been adverted to in the articles MILLER, W. H., and 

 PHILLIES, W. In the hands of the late Professor Armand Ldvy also, 

 and those of the late Mr. Henry James Brooke, F.R.S., distinguished 

 for his exact knowledge of minerals, and of his son, Mr. Charles 

 Brooke, F.R.S., it has greatly aided the progress of mineralogy and of 

 the knowledge of crystallised bodies in general. 



Huyghens [HUYGHENS, CHRISTIAN] had applied the undulatory 

 theory of light to the determination of the course of the extraordinary 

 ray in tho double refraction of Iceland-spar, a variety of carbonate of 

 lime. This was " a problem," Dr. Peacock has remarked, " of the 

 highest order of difficulty, whose solution, equally remarkable for its 

 completeness and geometrical elegance, was unfortunately left unno- 

 ticed or unknown until the beginning of the present century." " We 

 are indebted to Dr. Young " [YouNG, THOMAS], he continues, " for the 

 first suggestion, and to Dr. Wollaston for the first complete demon- 

 stration of its value, as giving results which are in strict accordance 

 with the observed laws of double refraction, which Newton had 

 unfortunately mistaken and misstated." Dr. Wollaston's demon- 

 stration is contained in his paper 'On the Oblique Refraction of 

 Iceland Crystal,' inserted in the 'Philosophical Transactions' for 

 1803. 



