VOL. LXXXVIir.] PHILOSOPHICAL TRANSACTIONS. 423 



[The water, and other substances described in the foregoing letter, were delivered to Mr. Hatchett, who 



had been previously requested, by the President and Council, to examine them. The result of his 



examination is as follows :] 



Analysis of the Water of the Mere of Diss. By Chas. Hatchett, Esq. 



The substances sent by Mr. Wiseman are as follow: Some copper wire, with a 

 blackish grey incrustation. Water from Diss Mere, (marked N° l). Copper 

 cuttings, covered with a blackish crust, similar to that on the copper wire, (marked 

 N° 2). Some cuttings similar to those above-mentioned (marked N° 3). The 

 paper, N° 4, contained some of the black crust, detached from the cuttings. N° 

 5, a quart bottle, containing some water from the lower part of the town of Diss, 

 and called, by Mr. Wiseman, a chalybeate water. N° 6, some flints, taken from 

 the s.e. side of the Mere, where the water is shallow, and having, as Mr. Wiseman 

 terms it, a metallic stain. 



My first experiments were made on the incrustation of the copper wire, men- 

 tioned in Mr. Wiseman's first letter. This incrustation was easily detached from 

 the wire, and being reduced to powder, was digested with nitro-muriatic acid, in a 

 gentle heat: a green solution was formed, and there remained a residuum, of a 

 pale yellow, which proved to be sulphur. The solution being diluted with 1 parts 

 of distilled water, was supersaturated with pure ammonia, by which, a few brown 

 flocculi of iron were precipitated. The supernatant liquor was blue; and being 

 evaporated, and re- dissolved by sulphuric acid, the whole was precipitated by a 

 plate of polished iron, in the state of metallic copper. The component parts of 

 this coating were therefore copper, and a very small portion of iron combined with 

 sulphur. I could not extend these experiments, as the whole quantity of the 

 coating that I was able to collect, amounted only to 3-i-gr.* 



The next experiments were made on the black crust of N° 2, 3, and 4. This 

 I found to be exactly the same as that formed on the copper wire; viz. it consisted 

 of copper combined with sulphur, and a very small portion of iron. 



I next examined the water of Diss Mere, (N° l) and I was at length led on, step 

 by step, to make a regular analysis of the fixed ingredients. Before making the 

 analysis, I examined this water with certain re-agents, and remarked the following 

 properties. 1. The water of Diss Mere has a yellowish tinge, and the flavour is 

 rather saline; but it has not any perceptible odour. 1. Prussiate of pot-ash did 

 not produce any effect. 3. Acetite of lead produced a slight white precipitate. 

 4. Nitrate of silver formed one, very copious. 5. Tincture of galls had not any 



* The copper w>re, when the coating was removed, was perfectly flexible, and the surface did not 

 appear unequal or corroded : this is commonly the case under such circumstances ; for, when sulphur 

 has combined superficially with a metal, the compound is observed to separate easily, so as to leave the 

 metal underneath not injured in quality, and very little, if at all, affected in appearance. Those who 

 diminish silver coin, make use of the following method. They expose the coin to the fumes of burn- 

 ing sulphur, by which a black crust of sulphurated silver is soon formed, which, by a slight but quick 

 blow, comes off like a scale, leaving the coin so little affected, that the operation may sometimes be 

 repeated twice or thrice, without much hazard of detection, if the coin has a bold impression.— Orig. 



