NATUKAL PHILOSOPHY. 203 



of the vessel be wet with water above the general level surface of the water, 

 and if the spirit be introduced in sufficient quantity in the middle of the vessel, 

 or if it be introduced near the side, the fluid is even seen to ascend the inside 

 of the glass, until it accumulates in some places to such an extent that its 

 weight preponderates, and it falls down again. The manner in which Mr. 

 Thomson explains these two parts of the phenomena is, that the more watery 

 portions of the entire surface, having more tension than those which are more 

 alcoholic, drag the latter briskly away, sometimes even so as to form a hori- 

 zontal ring of liquid high up round the interior of the vessel, and thicker than 

 that by which the interior of the vessel was wet. Then the tendency is for the 

 various parts of this ring or line to run together to those parts which happen 

 to be most watery, and so that there is no stable equilibrium, for the parts to 

 which the various portions of the liquid aggregate themselves soon become 

 too heavy to be sustained, and so they fall down. The same mode of ex- 

 planation, when carried a step further, shows the reason of the curious mo- 

 tions commonly observed in the film of wine adhering to the inside of a wine- 

 glass when the glass, having been partially filled with wine, has been shaken 

 so as to wet the inside above the general level of the surface of the liquid ; 

 for, to explain these motions, it is only necessary further to bring under con- 

 sideration that the thin film adhering to the inside of the glass must very 

 quickly become more watery than the rest, on account of the evaporation of 

 the alcohol contained in it being more rapid than the evaporation of the 

 water. On this matter Mr. Thomson exhibited to the Section a very decisive 

 experiment. He showed that in a vial partly filled with wine, no motion, 

 of the kind described, occurs as long as the vial is kept corked. On his re- 

 moving the cork, however, and withdrawing, by a tube, the air saturated 

 with vapor of the wine, so that it was replaced by fresh air capable of pro- 

 ducing evaporation, a liquid film was instantly seen as a horizontal ring 

 creeping up the interior of the vial, with thick-looking pendant streams 

 descending from it like a fringe from a curtain. He gave another striking 

 illustration by pouring water on a flat silver tray, previously carefully cleaned 

 from any film which could hinder the water from thoroughly wetting the 

 surface. The water was about one tenth of an inch deep. Then, on a little 

 alcohol being laid down in the middle of the tray, the water immediately rushed 

 away from the middle, leaving a deep hollow there, which laid the tray bare 

 of all liquid, except an exceedingly thick film. These and other experiments, 

 which he made with fine lycopodium powder dusted on the surface of the 

 water, into the middle of which he introduced alcohol gently from a fine 

 tube, were very simple, and can easily be repeated. Certain curious return 

 currents, which he showed by means of the powder on the surface, he stated 

 he had not yet been able fully to explain. 



LNTERESTIXG PHILOLOGICAL DISCOVERIES. 



At a recent meeting of the Asiatic Society, London, a communication was 

 read from Mr. Hodgson, who is at present residing in Central Asia for the 

 purpose of philological research. The writer has obtained thirty new vocab- 



