286 EXPERIMENTS ON VARIOUS ALLOYS OF GOLI>, 



XII. 



Experhnents and Obfcrvations on the various Alloys, on the Specific 

 Gravity, and on the comparative Wear of Gold, Abftracled 

 from the Memoir of Charles Hatchett, Esq.. F. R. S *. 



INTRODUCTION. 



Appointment of J. HE Lords of the Committee of his Majefty's mofl honour- 

 Ef ^nTc^Hat- able ^"*J Counci, » appointed by his Majefty, on the 10th of 

 chettEfq. to February, 1798, to take into confederation the Hate of the 



malceexpen- coins of this kingdom, having among other circum fiances re- 

 nientsonthe . ■■ ■' ? , . , , r . • . , , i i 



wear of gold} marked the confiderable lots which the gold coin appeared to 



have fuftained by wear within certain periods, and being de- 

 firous to afcertain whether this lofs was occafioned by any 

 defect, either in the quality of the ftandard gold or in the figure 

 or impreffion of the coins, were pleafed to requeft that Henry 

 Cavendifh, Efq. F. R. S. and the author of the prefent me- 

 moir would examine, by fuch experiments as fhould be deemed 

 requifite, whether any of thefe defects really exifted. 

 Two queftions were to be principally decided, 

 different m ift. Whether very foft and ductile gold, or gold made as 



compo tionj j^^ ^ .^ com ^' 1 \ ) \ e w j t jj t } ie p ro cefs f coining, fuffers the 



mod by wear, under the various circumftances of friclion to 

 which coin is fubje&ed in the courfe of circulation ? 



or in figure. 2dly. Whether coin with a flat, fmooth, and broad furface, 



wears lefs than coin which has certain protuberant parts raifed 

 above the ground or general level of the pieces ? 



Therefearch Is The great value of the material, had hitherto prevented pri- 

 vate individuals from ascertaining thefe facts by experiment . 

 and, as a public concern ; this fubjeci of invefligation, al- 

 though fo important to political economy and to fcience, does 

 not appear to have been noticed by any European government, 

 until the Right Honourable and enlightened Members of the 

 above-mentioned Committee propofed the inquiry, and furnifii- 

 ed the requifite means for making the experiments +. 



mew 



* In the Philofophical Tranfaftions for 1803. 

 f Thefe experiments were begun in the latter end of 1798, and 

 were completed in April, 1801. 



SECTION I, 



