444 
Proceedings of the Royal Society 
2. On Water, Hydrogen, Oxygen, and Ozone. By John 
Macvicar, D.D. Communicated by Dr E. Eonalds. 
3. Note on the Behaviour of Iron Filings, strewn on a 
vibrating plate, and exposed to the action of a magnetic 
pole. By Professor Tait. 
While a horizontal plate is in a state of rapid vibration (as in 
Chladni’s experiments), iron filings strewed on the surface, near a 
point of maximum vibration, are prevented from being scattered to 
the nodal lines by a magnetic pole held above the plate, but, if the 
pole be held helow^ they are speedily dissipated. If too powerful 
a pole be used, or if the magnet be held too near the plate, the 
filings nearest to the pole are not dispersed in the latter case. I men- 
tion this curious fact (which was observed recently by Mr Talbot 
and myself), on account of its explanation, which is very simple. 
The filings tend to place their greatest length in the direction of 
lines of magnetic force ; and thus, when the pole is above the plate, 
their upper ends incline inwards to it, so that the agitation of the 
plate, combined with the magnetic attraction, brings them nearer 
to the point immediately below the pole. When the pole is below 
the plate, the upper ends of the filings diverge from the pole, and 
the agitation sends them outwards, unless the magnetic attraction 
be considerable. 
4. On some Congenital Deformities of the Human Skull. 
By Wm. Turner, M.B., F.E.S.E. 
Is^, Scayhocephalus . — After making reference to his previous 
papers,* more especially to that in v/hich he had described several 
specimens of the scaphocephalic skull, in which he had discussed 
the influence exercised on the production of deformities of the 
cranium, by a premature closure or obliteration of the sutures, 
and to the recent memoirs of Professor \on Diiben of Stockholm,! 
* Natural History Review. January 1864, and January 1865. 
t Medicinskt Arehiv. Stockholm. Vol. ii. Part i. p. 1. 1864. 
