442 Intelligence and Miscellaneous Articles, 



and the author discussed the probable source of this heat, which he 

 was inclined to regard as a last trace of volcanic activity. 



2. " Vectisaurus valdensis, a New Wealden Dinosaur." By J. 

 W. Hulke, Esq., E.R.S., F.G.S. 



3. " On the Cudgegong Diamond-field, New South "Wales." By 

 Norman Taylor, Esq., of the late Geological Survey of Victoria; 

 communicated by B.- Etheridge, Esq., Jun., E.G.S. 



The author described in detail the various spots at which dia- 

 monds have been found in this locality. They occur in river-drift, 

 associated with gold and other gems. The drifts in the district are 

 at least six iu number. The oldest is considered by the author to 

 be Upper Miocene or Lower Pliocene ; the next Middle Pliocene ; 

 others Upper Pliocene, Pleistocene, and Becent. Between the 

 Middle and Upper Pliocene flows of basalt lava took place, which 

 have sealed up much of the older drifts. Diamonds are found in the 

 oldest drift and, probably by derivation from it, in the newer. 

 Gold, metallic iron, wood, tin, brookite (?), iron-sand, quartz, tour- 

 maline, garnet, pleonast, zircon, topaz, sapphire, ruby, and corun- 

 dum are also found. The author then considers the question of 

 whether the diamonds are derived from some of the igneous or 

 sedimentary formations (from Upper Silurian to Mesozoic) which 

 have contributed to the drift ; and concludes, from a variety of 

 reasons, that the diamonds have been formed in situ in the older 

 drift. 



4. " On the Occurrence of the Genus Dithyrocaris in the Lower 

 Carboniferous, or Calciferous Sandstone Series of Scotland ; and on 

 that of a second species of Anthrcipalcemon in these beds." By B. 

 Etheridge, Esq., Jun., E.G.S. 



LXIX. Intelligence and Miscellaneous Articles. 

 NOTE ON THE MAGNETIC EFFECT OF ELECTRIC CONVECTION. 



To the Editors of the Philosophical Magazine and Journal. 



Johns Hopkins University, 

 G-entlemek, Baltimore, April 8, 1878. 



OOME three years since, while in Berlin, I made some experi- 

 ^ ments on the magnetic effect of electric convection, which have 

 since been published in the ' American Journal of Science ' for Ja- 

 nuary 1878. But previous to that, in 1876, Professor Helmholtz 

 had presented to the Berlin Academy an abstract of my paper, 

 which has been widely translated into many languages. But, 

 although Helmholtz distinctly says " Ich bemerke dabei, dass der- 

 selbe den Plan fiir seine (Rowland's) Versuche schon gefasst und 

 vollstandig tiberlegt hatte, als er in Berlin ankam, ohne vorausge- 

 hende Einwirkung von meiner Seite," yet nevertheless I now find 

 that the experiment is being constantly referred to as Helmholtz's 



