RegnauWs Researches upon the Dilatation of Gases. 65 



mercury, but the mercury not coming completely in contact with 

 the tube, there would be a small portion of air adhering to it, 

 and as the mercury would rise in the tube, the air would enter 

 with it, and this is what Regnault here calls the phenomenon of 

 aspiration; this he avoided by surrounding that part of the tube 

 that was immersed in the mercury with tinfoil, and also by pour- 

 ing a quantity of concentrated sulphuric acid upon the surface 

 of the mercury. 



Second method : the results obtained by this method are — 



The mean of these is 1.3665. 



The following are the results of the four different methods 

 First series, ..... 1.36623 

 Second series, .... 1.36633 



Third series, .... 1.36679 



Fourth series, .... 1.36650 



Vol. xliv, No. 1. 



Mean, 



-Oct.-Dec. 1842. 



1.3665 



