INDEX II. 



127 



Towns, on the collection of water for the sup- 

 ply of, 100. 



, on the filtration of water for the supply 



of, 102. 



Unio, on a newly discovered species of, 42. 

 Uterine conception, on the comparative fre- 

 quency of, 85. 

 Uterine pregnancy, on a case of extra, 85. 



Valerianic acid, on the supposed formation 



of, from indigo, 33. 

 Vegetables, on the bitter principles of some, 



84. 

 Versailles railway accident, on the causes of 



the great, 97. 

 Vibration, on the alteration that takes place 



in iron by being exposed to long-continued, 



41. 

 Voltaic current of the frog, on the specific, 



38. 



Warington (Robert) on guano, 32. 



Water, on the collection of, for the supply of 

 towns, 100. 



, on the filtration of, 102. 



Wave, nature of the sound, 11. 



Waves, propagation of, in a resisted me- 

 dium, 8. 



Wealden strata of the Isle of Wight, on a 

 newly discovered species of Unio from tiie, 

 42. 



West (W.) on the mineral springs and other 

 waters of Yorkshire, 28, 105. 



on heating by steam, 35. 



Wheatstone (Prof.) on a singular effect of the 

 juxtaposition of certain colours under par- 

 ticular circumstances, 10. 



Whitby (Mrs.) on the cultivation of the silk- 

 worm, 73. 



Whitworth (Mr.) on an instrument for mea- 

 suring bodies to a very minute degree of 

 accuracy, 27. 



Whitworth (Mr.) on a new machine for as- 

 certaining the diameter of metallic cylin- 

 ders, 98. 



Williams (Dr.) on the removal of Taenia, 85. 



Williams (the Rev. David) on the Exeter 

 amygdaloid, 55. 



Winds, daily observations of the four classes 

 of, in each month of a cycle, 16. 



Wood (Dr. Thomas) on the electrolysotype, 

 a new photographic process, 36. 



Wood (S.) on an alligator in the freshwater 

 cliff at Hordwell, associated with extinct 

 mammaha, 50. 



WooUgar (J. W.) on the financial oeconomy 

 of savings banks, 92. 



Wylson (James) on the scantlometer, 99. 



York, curves of annual temperature at, 21. 



, on the sanatory condition of, during 



1839-1843, 90. 



, statistical notices of the state of edu- 

 cation in, 91. 



Yorkshire, mineral springs and other waters 

 of, 28, 105. 



, on the limestones of, 30. 



, birds of, 60. 



, on the fishes of, 62. 



, on the flora of, 70. 



Wolds, singular appearance of a thunder 



storm on, 23. 



Young (Prof.) on a principle in the theory of 

 probabilities, 1. 



on diverging infinite series, 1. 



Zinc, peculiar condition of, 35. 



, experiments with, on the limbs of a 



frog, 38. 

 Zoological nomenclature, on, 78. 

 Zoology, 59. 



, marine, 64. 



Zoophytes, on a new genus of helianthoid, 



65. 

 , on the morphology of the reproductive 



system of sertularian, 68,. 



THE END. 



