VUl CONTENTS. 



On the Colouring ]\Iatter of the Morinda citrifolia. By Dr Thomas 

 Anderson, . . . . , . .179 



An attempt to Improve the present Methods of determining the 



Strength and Direction of the Wind at Sea. By Professor Smyth, 180 

 On the Action of the Dry Gases on Organic Colouring Matters, 

 and its relation to the Theory of Bleaching. By Dr George 

 Wilson, ....... 183 



On the Products of the Destructive Distillation of Animal Sub- 

 stances. Part I. By Dr Thomas Anderson, . . 186 

 Note respecting the Refractive and Dispersive Power of Chloro- 

 form. By Professor Forbes, . . . .187 



Geological Notes on the Valleys of the Rhine and Rhone. By 

 Robert Chambers, Esq., ..... 189 



On the Classification of Colours. By Professor Forbes, . 190 



Description of a Mud-slide at Malta. By A. Milward, Esq. Com- 

 municated by the Secretary, . . . . .195 



An attempt to explain the " Dirt-bands" of Glaciers. By A. Mil- 

 ward, Esq., ...... 195 



On the rate of Progression of the Himalayan Glaciers. By Lieu- 

 tenant R. Strachey, Bengal Engineers, . . . 196 



Observations on the preceding Communications, and especially on 

 the Cause of the Annual Rings of Glaciers. By Professor Forbes, 196 



An Account of Camot's Theory of the Motive Power of Heat, with 

 Numerical Results deduced from Regnault"s Experiments on 

 Steam. By Professor William Thomson of Glasgow, . 198 



Theoretical Considerations on the Eflfect of Pressure in Lowering 

 the Freezing-Point of Water. By James Thomson, Esq., jun., 

 Glasgow. Communicated by Professor W. Thomson, . 204 



On the Early History of the Air-Pump in England. By Dr George 

 Wilson, . . . . . ' . . 207 



On the Classification of Colours. Part H. By Professor Forbes. 

 (See p. 190), . . . '. . .214 



Verbal Notice of Silicious Stalactites on Arthur's Seat. By the 

 Rev. Dr Fleming, . . . . . " . 216 



On some peculiar Impressions on the Surface of certain Strata of 

 Grey wack ' Schist, at Goldielands, in Roxburghshire. By James 

 Elliot. Communicated by David Milne, Esq., . . 217 



On the Causes of Local Peculiarities of Temperature in difl:erent 

 parts of Great Britain. By James Elliot. Communicated by 

 David Milne, Esq., . " . . . . .'218 



Verbal Notices. By the Rev. Dr Fleming, . . .219 



Notice by Professor Smyth of Locke's Electric Observing Clock, 220 



Abstract of a Communication on Rolling Curves, . . 222 



On the Extraction of Mannite from the Dandelion. By Messrs 

 Smith ; with an Analysis of the Mannite by Dr Stenhouse. Com- 

 municated by Dr George Wilson, .... 223 



On some new Voltaic Arrangements with Chlorous and Chromic 

 Acids, with an Account of a Battery, yielding electricity of great 

 intensity, in which the negative as well as the positive element 

 is Zinc. Bj' Dr Thomas Wright. Communicated by Dr G. 

 Wilson, . . . . . . .223 



