TABLE OF CONTENTS 



TO THIS TWENTY-FIRST VOLUME. 



SEPTEMBER, 1808. 



Engravings of the following Objects: 1. Dr. Traill's Mercurial Exhausting Ma- 

 chine: 2. Problem by J. Gougb, Esq.: 3. Mr. Hardy's Correction of Vibra- 

 tion in limekeepers: 4. Mr. Henry Ward's Compensation Pendulum; 

 5. -Mr. Furniss's Air-tight Door Hinge. 



I. A Mathematical Problem . by John Gough, Esq. - - 1 



IF. On the Incontrovertibility of Bark into Alburnum. By Thomas Andrevr 

 Knight, Esq. F. R. S. In a Letter to Sir Joseph Bauks^ K. B. P. R. S. 5 



HI. Account of a Mine of Zinc Ore, and its Application as a Paint. By the 

 Right Hon. Lord Ribblesdale, of Gisburne Park, Yorkshire - 1.2 



IV. On Oxalic Acid. Bv Thomas Thomson, M. D. F. R. S. Ed. Communicated 

 by Charles Hatchett, 'Esq. F. R. S. - - - - 14 



V. Analysis of some Iron Ores in Burgundy and Franche-Comte, to which is 

 .added, an Examination of the Pig-iron, Bar-Iron, and Scori:*, produced 

 ' irom them. By Mr. Vauquelin. - - - -32 



VI. On the Maddering of Cotton and Linen Thread, and Dyeing them Adria- 

 nople Red and other lixed Colours; and on Spontaneous Inflammations: by 

 John Michael Haussmann - - - - 44 



VII. Account of Inventions for equalizing the long and short Arcs of Vibration 

 in Timekeepers ; by Mr. WUiiam Hardy, No. 29, Coldbath Square 51 



VIII. Description of a Compensation Pendulum for a Clock, oi- Timepiece, 

 with Experiments. By Mr. Henry Ward, of Blaudford, in Dorsetshire 53 



IX. Account of a new air-tight Hinge for a folding Screen, or for a Door; by 

 Mr, Martin Furniss, No. 128, Strand - - - 61 



X. Description of an exhausting Machine on the Principle of, the Torricellian 

 Vacuum: by Dr. Thomas Stewart Traill - • - 63 



XI. Doubts respecting some of the received Doctrines of Chance. In a Letter 

 from a Correiponderit - - - - - 66 



XII. Letter from a Correspondent on the laic Discovery of Metals in the fixed 

 Alkalis ------ 6S 



XIII. OntheDecompo:/!(ion of the Alkalis. In a Letter from Mr. William 

 Cook ------ 69 



XIV. On the Quantity of Fccula in difterent Varieties of the Potatoe. By 

 Mr, William Skrimshire, Jun, - - - - 71 



Scientific News - - - - -'. - 77 



Account of the Situation of the Instruments employed by Mr. Robert Bancks, 

 for the Meteorological Journal - - - - 79 



Meteorological Journal - • - - - SO 



OCTOBER 



