422 PHILOSOPHICAL TRANSACTIONS. [~ANNO *798. 



I have never met with an account of the decomposition of copper, in waters 

 impregnated with iron, in any chemical work; and as iron appears to have a greater 

 affinity to the vitriolic acid than copper has, as is constantly evinced in the neigh- 

 bourhood of copper mines, it appears an anomaly in chemistry, that I am not adept 

 enough in the science to account for. 



[The President and Council, thinking the effects of the water of Diss Mere deserving of further in- 

 quiry, desired Mr. Wiseman would send some of the said water, for the purpose of examination. 

 Mr. Wiseman accordingly sent a quantity of the water, accompanied by the other substances de- 

 scribed in the following letter to the President, dated Diss, May 29, 1798] 

 " As the Society have expressed a wish, through Mr, Frere, to have some of 

 the water in which the copper wire was deposited, which Mr. Frere, at my request, 

 laid before the Society, I have sent 2 gallons of the water of Diss Mere, (N° J), 

 with a small quantity of copper cuttings, (N° 2), which laid in the same water, a 

 few feet from the side, and 6 feet in depth, from the 7th of February, 1797,' to 

 the 20th of the present month, May, 1798. The pieces of copper, when laid in, 

 weighed 3051 gr.; when they were taken out, and washed from the mud that 

 lightly adhered to them, preserving and weighing the scaly matter that came of£ 

 they weighed 2944 grs., indicating a loss of 107gr. Examining the pieces of 

 copper, the same evening they were taken out of the water, I observed a number 

 oY small crystals formed on some of them, in the form of pyramids joined at their 

 bases; these crystals lost their shining appearance, by the evaporation of the water 

 of crystallization, in the warmth of the succeeding day. Whether they will be 

 preserved in a journey of nearly 100 miles, is perhaps doubtful. N° 3 contains 2 

 pieces of copper, on which the crystals were most abundant. N° 4 contains a 

 small quantity of the substance formed on the copper, that came off in washing and 

 in weighing it. 



The town of Diss is principally situated on the n.n.e. and e. sides of this piece of 

 water. The land runs pretty steep on the w. and n. of it, to the height of 40 or 

 50 feet: on the s.e., the ground comes within a few feet of the level of it. The 

 soil of the upper part of the town is a stiff blue clay; that of the lower part, to 

 the s.e., a black sand, beneath which it is a moor. The water in the higher parts 

 of the town is good; in the lower parts, it is a chalybeate, of which a specimen is 

 sent, (N° 5). N° 6 contains a quantity of flint stones, taken from the s.e. side of 

 the Mere, where the water is shallow; many of which are strongly marked with 

 the metallic stain, which they acquire by lying in this water a few years. 



The Mere contains about 8 acres, and is of various depths, to 24 feet: from its 

 situation with respect to the town, it may naturally be supposed to contain a vast 

 quantity of mud, as it has received the silt of the streets for ages. In summer, 

 the water turns green ; and the vegetable matter that swims on its surface, when 

 exposed to the rays of the sun, affords vast quantities of oxygen gas. I cannot 

 help considering this process as having a considerable agency in the corrosion, and 

 in the formation of the metallic crust on the copper deposited in this water. Some 

 of this vegetable matter will be found, in the water sent to the Society," 



