Some Physical Properties of Nitric Acid Solutions. 



99 



Results at 4' 



Results at 14'2. 



Results at 24-2. 



It will be evident that in all cases the results up to 19'37 lie upon 

 the straight line drawn from the 4 per cent, origin, and on the other 

 hand those 21-98 upwards lie upon the straight line from the 21 per 

 cent, origin, while the intermediate values lie below both lines. As it 

 would appear from a consideration of the examples given above that 

 the observations in the vicinity of critical points may be represented in 

 certain cases as on either, and in others as on neither of the lines 

 meeting at those points, then such points may be regarded as in a 

 certain sense ideal, and the phenomena as continuous. Some such 

 possibility might tend to overcome the mental difficulty experienced 

 by certain writers as regards the manifestation of sudden irregularities, 

 and throughout the whole course of events from commencement to 

 conclusion one is dealing with combined water and free water, with 

 combined acid and free acid, and in the more dilute solutions with 

 integral or undecomposed molecules as also with their respective ions. 



