iv 
Monday , \Qth April 1855. 
PAGE 
Notice of Some new Forms of British Fresh- Water Diato- 
macese. By William Gregory, M.D., Professor of 
Chemistry, ..... 306 
On Glacial Phenomena in Peebles and Selkirk Shires. By 
Robert Chambers, Esq., &c., . . . 308 
Preliminary Notice on the Decompositions of the Platinum 
Salts of the Organic Alkalies. By Thomas Anderson, 
M.D., Regius Professor of Chemistry in the University 
of Glasgow, . . . . .309 
On the Volatile Bases produced by Destructive Distillation 
of Cinchonine. By C. Greville Williams, Assistant 
to Professor Anderson, Glasgow University, . 314 
Monday , 30th April 1855. 
Remarks on the Coal Plant termed Stigmaria. By the Rev. 
Dr Fleming, . . . . .316 
On Errors caused by Imperfect Inversion of the Magnet in 
Observations of Magnetic Declination. By William 
Swan, Esq., ..... 318 
On the Accuracy attainable by means of Multiplied Obser- 
vations. By Edward Sang, Esq., . .319 
