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XXXVII. On the Spheroidal Condition of Liquids, 

 Py W. G. Armstrong, Esq. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 

 A T the recent meeting of the British Association at Cam- 

 •^^ bridge, I had the pleasure of witnessing M. Boutigny's 

 pleasing experiments on the spheroidal condition of liquids; 

 and since my return to Newcastle I have exhibited the same 

 experiments to the Philosophical Society of this town, accom- 

 panied by explanatory observations, the substance of which I 

 take the liberty of communicating to you for insertion in the 

 Philosophical Magazine. This I am induced to do, not only 

 because I conceive that observations upon a subject so much 

 before the public as this is at present, are likely to be interest- 

 ing to a considerable portion of your readers, but also because 

 the explanation of the phaenomena is still in some measure a 

 matter of controversy. 



Although M. Boutigny's experiments embody no new dis- 

 covery, yet they have the no small merit of showing in a stri- 

 king and prominent manner, effects with which most persons 

 are in some degree acquainted, but which fail to excite atten- 

 tion in consequence of the unattractive form in which they are 

 commonly observed. 



The fundamental experiment of the series consists in drop- 

 ping water upon a metallic plate or dish to which heat is ap- 

 plied. If the dish be heated to 212° or upwards, the water 

 immediately boils and is dissipated in vapour, provided the 

 temperature of the dish do not exceed a certain limit; but if it 

 do exceed that limit, then the condition of the liquid is en- 

 tirely changed and the following effects may be observed : — 



1st. The ebullition of the water, instead of being accele- 

 rated, is altogether prevented, and the evaporation is greatly 

 retarded. 



2nd. The water assumes a rounded or ^^ spheroid aV^ form, 

 like a globule of mercury. 



3rd. The water does not touch the dish, being separated 

 from it by a thin interposing stratum of vapour, 



^th. The temperature of the water never rises above 205° 

 (96 centigrade), being 7° below the boiling-point, 



A tolerably correct idea may be formed of the spheroidal 

 condition of water by reference to the annexed diagrams. 

 Fig. 1 represents a dish containing water in the spheroidal 

 form, and, by way of contrast, the diagram fig. 2 represents a 

 similar dish containing water which is not in the spheroidal 

 form. 



Phil. Mag. S. 3. Vol. 27. No. 180. October 184.5. S 



