2SG PHILOSOPHICAL TRANSACTIONS. [aNNO 1738. 



MatthicE Belli, Pannonii, R. S. Lond. S. &c. Observatio Historico-Physica de 

 ^4quis Neosoliensium JEratis, vulgo Cement- Wasser dictis, Ferrum jEre 

 permutantibus, in Epistold ad illustr. Dm. Hans Sloane Bart. &c. scripid, 

 co7nmu7iicata. N° 450, p. 351. 



This pnper gives an account of tiie copper waters (cement-wasser) in the 

 copper-mines near the town of Neusol in Hungary. The rain, or spring water, 

 as it percolates through the sides of the excavations worked in these mines, be- 

 comes impregnated (from its action on the copper-pyrites) with vitriol of cop- 

 per, and is conveyed by numerous channels into large wooden cisterns, or re- 

 servoirs, placed in various parts of the mines. When pieces of iron are thrown 

 into the water collected in these reservoirs, and are suffered to remain therein 

 for a sufficient length of time, they are, according to the belief of the vulgar, 

 turned into copper ; i. e. the copper is precipitated upon the surface of the iron 

 in its metallic state.* It is afterwards scraped ofFfrom the iron, and melted and 

 wrought into a variety of utensils. The copper thus obtained is found to be 

 exceedingly pure.-f- — Respecting the proportion of vitriol of copper in this so 

 called ceinent-water, Mr. B. states that Ibj (medicinal weight) of the said water, 

 when evaporated to dryness, gave giiss of residuum, which, being dissolved in 

 pure water, yielded a green solution. When this solution was afterwards 

 filtered and evaporated, Mr. B. obtained 9ij of crystallized vitriol, [vitriol of 

 copper] besides grs. of a yellow precipitate. 



Of a Bubonocele or Rupture in the Groin, and the Operation upon it ; by C. 

 Amijand, Esq. Serjeant-Surgeon to His Majesty, and F. R. S. N° 450, p. 36l . 



October 8, 1737, Mrs. Bennet, 70 years of age, of a thin habit of body, 



*Tliis apparent transmutation of iron into copper is easily explained by the laws of chemical attraction. 

 The vitriolic acid, with which the copper is combined in the so called cement-water, having a greater 

 afBnity for iron than for copper, it deserts the latter to unite with the former. Accordingly, when 

 a piece of iron is thrown into such water, it is immediately acted upon by the vitriolic acid, that acid 

 dissolving and combining with a portion of the iron, and letting fall the copper in its metallic state, 

 which, during its precipitation attaches itself to the surface of the undissolved portion of iron. 

 There is, therefore, in this instance no transmutation of one metal into another ; but merely a de- 

 composition and a new chemical union produced by the force of elective attraction, the iron being 

 combined with the acid in place of the copper, and the latter being precipitated in its metallic 

 state. 



t This mode of obtaining copper is practised in many other countries besides Hungary, the water 

 collected in, or issuing from most copper mines holding more or less vitriol of copper [sulphate of 

 copper] in solution. Considerable quantities of copper are annually separated from the water of the 

 copper-mines in Anglesey by means of iron, as at Neusol. 



