NATURAL PHILOSOPHY. 193 



WIND OF A SHOT. 



The following extract from an Indian letter confirms the doubts entertained 

 as to deaths attributed to the " wind of a shot " : " Brigadier Russell is also 

 about to leave the army, under the advice of a medical board. Never, per- 

 haps, in all the chances of war, has there been such an escape as his. A can- 

 non ball cut the gold watch-chain at the back of his neck as cleanly as if it 

 had been a pair of nippers, and did him no further injury, except inflicting 

 a shock to his nervous system." Medical Times and Gazette. 



SOLAR REFRACTION. 



Professor Thomson has applied the term " solar refraction " to characterize 

 an effect deduced theoretically from the dynamical theory of heat, which, if 

 proved to exist, will result in important consequences to every department of 

 astronomy ; for it at once infers the necessity of the existence of a medium 

 pervading space of similar constitution to our own atmosphere, and under- 

 going, by necessity, a condensation in the neighborhood of the sun. Hence, 

 also, there cannot but arise a refraction of objects beyond the sun, when this 

 body crosses their line of direction. When Professor Piazzi Smith tested 

 this " solar refraction " by the observation of stars transiting the meridian 

 near the sun, the results, as far as they could be deduced, showed the exist- 

 ence of this " solar refraction," and, with it, of a resisting medium filling 

 space, and forming a material connection still between the sun and all the 

 planets. 



PROF. FORBES ON SOME PROPERTIES OF ICE NEAR ITS MELTING- 

 POINT. 



Prof. Forbes has communicated to the Royal Society of Edinburgh the 

 results of some experiments made by him on the properties of ice near its 

 melting-point, with particular reference to those of Mr. Faraday, published 

 in the Athenceum for June, 1850, to which attention has been more lately called 

 by Dr. Tyndall and Mr. Huxley, in relation to the phenomena of glaciers. 

 The substance of Prof. Forbes's statement is as follows : 



" Mr. Faraday's chief fact, to which the term * regelation ' has been more 

 lately applied, is this : that pieces of ice, in a medium above 32, when closely 

 applied, fi'eeze together, and flannel adheres apparently by congelation to ice 

 under the same circumstances. 



"1. These observations I have confirmed. But I have also found that 

 metals become frozen to ice when they are surrounded by it, or when they 

 are otherwise prevented from transmitting heat too abundantly. Thus, a pile 

 of shillings being laid on a piece of ice in a warm room, the lowest shilling, 

 after becoming sunk in the ice, was found firmly attached to it. 



" 2. Mere contact, without pressure, is sufficient to produce these effects. 

 Two slabs of ice, having their corresponding surfaces ground tolerably flat, 

 were suspended in an inhabited room upon a horizontal glass rod passing 

 through two holes in the plates of ice, so that the plane of the plates was 

 vertical. Contact of the even surfaces was obtained by means of two very 

 weak pieces of watch-spring. In an hour and a half the cohesion was so 



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