338 Dr. Peschier on the State of Potash in Plants, [Nov. 



will be possible to give nothing more than the titles of the 

 remaining dissertations of Bergman, with the date of the publi- 

 cation of each. 



23. On the different Quantity of Phlogiston in Metals. 1783. 



24. On Sulphuret of Tin. 1781. 



25. On the Sulphurets of Antimony. 1782. 



26. On the Products of Volcanoes. 1777. 



27. On Elective Attractions. 1775. 



28. On the Analysis of Lithomarga. 1782. 



29. On Asbestus. 1782. 



30. Thoughts on a Natural System of Minerals. 1784. 



31. On the Combination of Mercury and Muriatic Acid. 1769. 



32. On the proper Mode of burning Bricks. 1771. 



33. On the Acidulous Waters of Medevi. 1782. 



34. On the Medicinal Springs of Lokarne. 1783. 



35. On Cobalt, Nickel, Platina, and Manganese ; and on 

 t,hc Nature of their Precipitates. 1780. 



36. Chemical Analysis of Indigo. 1776. 



37. On Vegetable Soils. 1771. 



'&* 



38. On the Mountains of Westg-othland. 1768 



o ■ 



39. On the latest Chemical Discoveries. 1777. 



40. Mineralosrical Observations. 1784. 



Article II. 



On the State in which Potash exists in Vegetables, and on the 

 Saccharine Matter of the Potutoe. By Dr. Peschier. 



(To Dr. Thomson.) 



SIR, Edinburgh, Aug. 12, 1818. 



The enclosed was sent me by Lord March, that it might be 

 transmitted to you ; the author being desirous that, if approved 

 of, the discovery contained in it might have a place in your 

 journal. I am, Sir, with esteem, 



Your obedient servant, 



John Playfair. 



(To Lord March.) 



MY LORD, Geneva, July 20, 1818. 



You are too great a friend of the sciences, and I take too 

 much pleasure in communicating to you the discoveries which 

 may originate in this city> to allow you to remain ignorant of 

 some new facts ascertained in the laboratory of my brother, and 

 which will soon be communicated to the public. 



The chemical analysis of vegetables having been for some 



