CONTENTS. 



Analysis of Arsenical Nickel, and the Arseniale of Nickel of AU 

 lemont [Department of the Isere). .. ,. .. 295 



A Letter from Dr. Hutton; with Communications from the 

 Marquis De L.KPLACE.. ,, .. .. .. 521 



On the Dry-Rot in Timber 326 



0?i some Combinations of Platin?on. .. .. .. 330 



On the recent Alterations said to be male by some Timers of 

 Musical Instruments, in the Places of the Pf'olves, or largely 

 tempered Concords, on common \2-stringed or Douzeaue 

 Keyed- Instruments. With some Queries thereon, to Musi- 

 cians. . . .. .. .. .. .. .. 341 



On the Methods of cutting Rock Crystal for Micrometers. 343 



On Mr. Bonnycastle's Dissertation on the Influence of 

 Masses of Iron on the Mariners' Compass published in our 

 55th Folume. 34G 



Copy of the Report to the Secretary of State for the Home 

 Department, from the National Paccine Establishment ; 

 dated ISth May \S20. 350 



On the Lunar Period. ., . . . . . . . . 354 



On the" Connoissance des Tems pour V An 1820." . . 359 



An entirely New Method of extracting the Cube Root in Num- 

 bers. . . . . . . . . . . . , 360 



Description of Mr. M\lam's Gas-Meter. .. .. 363 



Thoughts on the Probability, Expediency and Utility of dis- 

 covering a Passage by the North Pole. . . . . 366 



Observations on M. Arago's " Reclamation " respecting his 

 Ocular Micrometer, published in the Annales de Cbimie ct 

 de Physique. .. .. ,. .. .. .. 401 



On the Sugar and Spirits obtained in Dalmatia from the Fruit 

 of the common Arbutus. .. .. ; .. 406 



Remarks on Mr. Yea tes's Papers on the Lunar Theory. 408 



On the Specific Gravities of the Gases, and th^ different Musical 

 Sounds which they occasion in the same Organ-Pipe. 412 



On the Cjilture of Carrots 416 



Note upon the Combination of Sulphur uith Chrome, ami upon 

 a new Process for obtaining the Oxide of that Metal. 433 



On the late Lunar Occultalion of Jupiter; with Remarks on the 

 late Solar Eclipse. . . . . . . . . • . 434 



New Method of congraliug JFaler in a Facunm. . . 4.16 



