14 On the Pyrolig7ieom yield. 



Tl»e ham sent for the Society's examination has been cured 

 in the usual way recommended for Westphalia hams ; the acid 

 was employed, instead of being smoked, two table spoonfuls of 

 the acid being added to the pickle ; and when the ham is to be 

 removed from the pickle, it must be well washed in cold spring 

 water and dried, and then some of the acid applied over it by 

 means of a brush, and this repeated two or three times at about 

 a week's interval. 



Herrings Mr. S. cures with very little salt. Being well dried, 

 as early after being caught as can be effected, they are then 

 dipped into a vat of the acid, and when dry, the same process 

 repeated a few times, suspending them like the manufacture of 

 candles. Mr. S. entertains no doubt, from the result of his ex- 

 periments with herrings, that the same process would answer for 

 other kinds offish, as salmon, cod, &:c. ; and hence, when cooked, 

 may be salted according to each individual's taste. The red co- 

 lour, in dried salmon and herrings, has been generally attributed 

 to nitre; very frequently tobacco, dissolved in a fluid not very 

 agreeable (urine), is made use of in Holland. 



I presume this acid would be found very useful on board any 

 vessel fitted out for long voyages ; it appears from calculations 

 on a small scale, that one hogshead of this acid would suffice to 

 cure six tons of fish, in such a manner as to retain their nutri- 

 tious quality; and they could be cured on board when oppor- 

 tunities occurred of procuring them, independent of its being an 

 excellent substitute for common vinegar in many culinary pur- 

 poses on board. 



At the next meeting of the Society, I indulge a hope that I 

 shall be enabled to lay before them a memoir containing a detail 

 of experiments, in which I am at present engaged, to counteract 

 the effects which are experienced in the vicinity of copper and 

 lead works. I do not believe that any of the western counties 

 are subjected to the melancholy influence of such smelting ma- 

 nufactories. In different parts of Wales, Derbyshire, Northum- 

 berland and Yorkshire, many thousand acres of land are nearly 

 rendered incapable of producing vegetable matter, and the little 

 pasturage they do a.Tord proves very destructive to any animals 

 feeding thereupon. In the smelting houses below Swansea and 

 Neath, the atmosphere is obscured by clouds of smoke, highly 

 charged with sulphureous and arsenious acid ; which, when pre- 

 cipitated on fields, where cattle are feeding, produce such effects 

 as might be expected from the agency of such poisons inducing 

 large swellings on their joints, a complete change in the form 

 of their feet, which must arise from local applications; also all 

 the teeth, instead of being perpendicular to the jaws, are brought 



into 



