xlii FOURTH REPORT — 1834. 



Account of the progress of experiments on the nature of the 

 Secretions from the Roots of Vegetables. By Dr. Daubeny, Pro- 

 fessor of Chemistry and Botany, Oxford. 



Notice of the progress made in the comparative analysis of 

 Iron in the different stages of its manufacture. By Professor 

 Johnston. 



Notice of the progress made in determining the specific gravi- 

 ties of Oxygen, Hydrogen, and Carbonic Acid. By Dr. Dalton. 



Account of researches on the effects of Poison on the animal 

 ceconomy. By Dr. Roupell and Dr. Hodgkin. 



Account of researches on the Sensibilities of the Nerves of 

 the Brain. By Dr. Marshall Hall and S. D. Broughton. 



Account of the performance of a Chronometer with a Glass 

 Balance-spring. By E. J. Dent. 



Notice of the performance of an Instrument for ascertaining 

 the quantities of mud transported by Rivers. By George Ren- 



III. Notices in reply to Queries and Recommetidations of 

 the Association. 



On the electrical condition of Metalliferous Veins. By R. W. 

 Fox. 



On the peculiar circumstances attending certain Coal Di- 

 stricts in the midland counties of England. By R. I. Murchison. 



On the direction &c. of Non-metalliferous Fissures. By Pro- 

 fessor Phillips. 



On the Limestone of Closeburn. By C. G. S. Menteath. 



On the Beds inclosing the Haematite of Dalton. By Professor 

 Sedgwick. 



On the supposed Metamorphosis of Crustacea. By J. O. West- 

 wood. 



On the progress made in inquiries relative to the Secretions 

 from the Roots of Vegetables. By Dr. Dunbar. 



On the nature and quantity of the Gases given off from Ther- 

 mal Springs. By Dr. Daubeny. 



On the purity and specific gravity of Mercury, Dr. Thompson 

 remarked that he considered the mercury as imported into this 

 country to be pure, and the specific gravity assigned to it by 

 Cavendish to be correct, as it agrees with recent determinations 

 by Mr. Crichton, from experiments continued through a whole 

 winter. 



On products collected in Chimneys of Furnaces. By Mr. 

 Lowe. 



