Diffusion ofar&enical Vapours from Copper-smeltiiig Furnaces. 33 



animal life in that vicinity. Thousands of acres are rendered . 

 useless entirely from the arsenic falling in showers upon the 

 surface of the land ; and, indeed, numberless instances have 

 occurred of the teeth dropping from the mouths of cattle that 

 have grazed in the neighbourhood of these furnaces, and, upon 

 examination of such teeth, they have been found to be coated 

 with a strong crust of copper. Several chemical and mechani- 

 cal projects have been adopted to prevent the escape of these 

 substances from the chimney of the smelting furnace ; and al- 

 though their effects have been confined within the works, yet 

 it has been found attended with considerable trouble and ex- 

 pense, which the copper-smelters seem unwilling to adopt in 

 their daily practical operations. " The Cadoxton experiments," 

 as stated in this report, seem fiiUy to remove the objections of 

 the smelters, and yet obviate all the inconvenience to the sur- 

 rounding country. The discovery was first announced by the 

 following paragraph in the Swansea paper : 



" An experiment has been made at Cadoxton, in Glamor- 

 ganshire, for obviating the inconveniences arising from the cal- 

 cining and smelting of copper ores, by destroying the noxious 

 qualities of the smoke from the furnaces upon the whole pro- 

 cess, and by destroying or reducing as much as possible the 

 bituminous smoke, upon a plan adapted to the present practical 

 operations of copper-making, and without increased expense to 

 the manufacturer." — Cambrian, Nov. 24, 1821. 



The principle aimed at in this experiment is simple precipi' 

 tatioii; the mode of effecting it by gaining as much time as 

 possible between the production of the smoke in the ftirnace 

 and its final exit into the atmosphere ; in shoit, by imitating as 

 nearly as possible the condensation of vapour in a still, where 

 the worm (presenting the gi-eatest possible surface in the smallest 

 possible space) may be considered the flue: if the flue in this 

 case could be conveniently passed through a cold medium (as 

 the worm of a still), the imiUition would be still nearer; but it 

 should seem, from the result of this experiment, that it is not 

 necessary. The experiment was as follows : 



A calcining furnace (which throws out the greatest portion 

 of noxious ingredients) of the ordinary dimensions lias been 

 erecteil ; instead of a short perpendicular flue, an horizontal 

 flue was carried from it on the surface of the ground, or rather 

 a set of connected flues, 24 in number, consisting of straight 

 parallel lines rounded off at the ends, and fiirnislied with doors 

 for the ])urp()se of observation, each line being .'54 feet in length; 

 from the end of this line tlie flue was continued lor somedistance 

 to the j)its of a neiglibouring lime-kiln 22 leet dee)), which was 

 furnished with a brick cap in the .sluipe of a cone, termhiating 

 Vol. GO. No. 291. t/7//3/ 1822. E at 



