I 
h CONTENTS. 
Optics. 10. Optical Structure of Melted Quartz. 11. Sin- - 
gular Properties of Chlorophaeite, found in Scotland and 
Iceland, . - - - - 433, 434 
Magnetism. 12. Dr Wollaston’s Explanation of the Electro- 
Magnetic Phenomena. 13. Ampere’s Electro-Magnetic Te- 
legraph* 14. Cause of the Diurnal Variation of the Needle. 
15. Mr Lecount’s Method of finding the Dip of the Needle. 
16. Account of two large Loadstones, - 435-437 
ElectricitV. 17. Excitement of Muscular Fibre by Voltaic 
Electricity. 18. Experiments on the Electric Spark, 437, 438 
Hydrodynamics. 19. Compressibility of Water. 20. Per- 
kins’ Method of keeping off the Back-Water from Mills, 438, 439 
Meteorology. 21. Meteorological Table, and Temperature 
of Springs at Leith for 1820. 22. Mean Temperature at 
Carlsruhe for 20 years, &c. 23. Meteorological Table kept at 
Kinfauns for 1820. 24. Vegetation on the Himalaya Moun- 
tains. 25. Mean Temperature of I8I9 and 1820 at Chu- 
nar* 26. Mean Temperature of Melville Island, 439-443 
II. CHEMISTRY, 
27. M. Grotthus’s Method of Freezing Water in vacuo the 
same as Nairne’s. 28. Solution and Crystallization of Lime. 
29. Mercurial Atmosphere. 30. Bicarbonate of Ammonia. 
31. On the Alloys of Platinum. 32. Composition of Rhu- 
barb. 33 . On the Colouring Matter of the Shell of the 
Crab. 34. On the Colouring Matter of the Membrane 
which lines the Shell of the Crab. 35. On the Alloys of 
Potassium and Sodium with other Metals. 36. Doberei- 
ner on the chemical action of Capillary Tubes. 37. Exist- 
ence of Alcohol in Pyrolignous Acid, - 443-448 
hi. General science. 
38. Mr Campbell’s second Journey in Africa. 39* Destruc- 
tion of the village of Stron. 40. Weight of the Dutch Pound 
Troy. 41. Black Resinous Varnish used at Silhet in Ben- 
gal. 42. Manufacture of Catgut Strings. 43. On the Se- 
lection of Ice for Ice-houses. 44. Printing from the Fusible 
Metal, . - - - V 448-451 
Art. XXXIX. List of Patents granted in Scotland since 23d 
November 1820, - - 451 
List of Plates, - 452 
INDEX, - - . . 453 
