>V CONTENTS. 



Mr. J. Bateman on the Use of the SHding Rule, with an account of some New 



Lines proposed for it 42 



Mr. Edmund Bowman on Determining Distances by the Telescope 42 



Mr. De Moleyns on recent Discoveries in Voltaic Combination 42 



Mr. Grellet on an Instrument for Drawing Circles in Perspective 42 



Mr. W. G. Gutch's Notice of certain Barometers invented by Mr. Bursill 42 



CHEMISTRY. 



Mr. J. Prideaux's Inquiries into the Causes of the increased Destructibility 



of Modern Copper Sheathing 43 



Mr. R. Hunt on the influence of the Ferrocyanate of Potash on the Iodide of 



Silver, producing a highly sensitive Photographic Preparation 47 



Professor Daubeny on Manures considered as Stimulants to Vegetation 47 



on the Disintegration of the Dolomitic Rocks of the Tyrol 48 



Dr. Samuel L. Dana's Practical Method of determining the Quantity of Real 



Indigo in the Indigos of Commerce 49 



Mr. Goldsworthy Gurney's Experiments showing the possibility of Fire, 



from the Use of Hot Water in warming Buildings, and of Explosions in 



Steam-engine Boilers 49 



Mr. A. Booth on Spontaneous Combustion 50 



Mr. E. A. Paknell on some instances of Restrained Chemical Action 51 



' on some subjects connected with the Sulphocyanides 51 



Mr. G. FoWNES on the direct Formation of Cyanogen from its Elements 52 



Dr. Playfair's Abstract of a Letter from Professor Liebig 53 



Mr. Robert D. Thomson's new extemporaneous Process for the Production 



of Hydrocyanic Acid for Medical Use 54 



on the Composition of Crystallized Diabetic Sugar 54 



Professor Bunsen on the Radical of the Kakodyle Series 55 



Mr. E. Lankester on the Production of Sulphuretted Hydrogen by the Action 



of Vegetable Matter on Solutions containing Sulphates 57 



Mr. Frederick De Moleyns's Inquiry into the Nature and Properties of the 



new Element, or product of Electrical Action mentioned by Schiinbein 57 



GEOLOGY AND PHYSICAL GEOGRAPHY. 



Mr. J. E. Bowman on the Upper Silurian Rocks of Denbighshire 59 



Mr. Bartlett on the Post-Tertiary Formations of Cornwall and Devon 61 



Mr. C. W. Peach's Account of the Fossil Organic Remains of the South-east 



Coast of Cornwall, and of Bodmin and Menheniott 61 



Rev. D. Williams on the Stratified and Unstratified Volcanic Products in the 



neighbourhood of Plymouth 61 



Mr. E. Moore on the discovery of Organic Remains, in a raised beach, in the 



Limestone Cliflf under the Hoe at Plymouth 62 



