CONTENTS 



OF THE 



EDINBURGH JOURNAL OF SCIENCE. 

 No. XVIII. 



Page 

 Art. I. Physical Notices of the Bay of Naples. Communicated by the Author 



in a Letter to the Editor, - , - 189 



II. Account of an Apparatus for grinding and polishing the Specula of 

 Reflecting Telescopes. By the Right Honourable Lord Oxman- 

 town, M. P. Communicated by the Author, - 213 



III. Experiments with the Vegetable Poison with which the Nagas are 

 stated to tip their Arrows. By P. Breton, Esq. Surgeon Superin- 

 tendant of the School of Nativg Doctors, Calcutta. Communicated by 

 George Swinton, Esq. - 217 



IV. Farther Observations on the Construction of Achromatic Telescopes 

 with a fluid concave lens, instead of the usual lens of Flint Glass. By 

 Peter Barlow, Esq. F. R. S. &c. - - 220 



V. On the time at which Nearchus left the Indus. Communicated by 



the Author. .... 225 



VI. On the relative quantities of Steam condensed in vessels with bright 

 metallic and blackened surfaces. By R. W. Fox, Esq. Vice-President 

 of the Royal Geological Society of Cornwall. Communicated by Wil- 

 liam J. Henwood, F. G. S. - - - 232 

 VII. Account of the Climate and Agriculture of Soobathoo and Kotgurh. 

 By Captain Patrick Gerard of the Bengal Native Infantry. 

 Communicated by the Author, - - 233 

 VIII. Observations on Ventriloquism. By Dugald Stewart, Esq. 241 

 IX. Account of the Performances of different Ventriloquists, with Obser- 

 vations on the Art of Ventriloquism, - - 252 

 X. On a Mass of Native Iron from the Desert of Atacama in Peru. 

 By Thomas Allan, Esq. F. R. S. E. - - 259 

 XI. Examination of the Specimen of Native Iron from the Desert of 

 Atacama in Peru. By Edward Turner, M. D. F. R. S. Ed. Pro- 

 fessor of Chemistry in the London University, - 262 

 XII. Table of the Variations of the Magnetic Needle, according to the 

 latest observations. By Professor Hansteen. Communicated by 

 the Author, - ... 264 

 XIII. On the Parasitic Formation of Mineral Species, depending upon 

 Gradual Changes which take place in the Interior of Minerals, while 



