CONCENTRATED AQUEOUS SOLUTIONS, AND HYDRATION OF THE SOLUTE. 859 



In the diagram on p. 860, fig. 3, curves have been drawn by plotting values 

 of the elevation of the boiling point against the number of grammes of salt added to 

 100 grammes of water. These show that for some salts elevation increases at a much 

 greater rate per gramme of salt added than for others. The above curves for the very 

 deliquescent salts, viz. calcium chloride, lithium bromide, and lithium chloride, 

 indicate that elevation of boiling point with increase of concentration increases 

 at an increasing rate up to a certain concentration, and falls off very considerably 



elevation pep gramme equivalents 

 Fig. 1. 



GRAMME EQUIVALENTS PER LITRE 



Fig. 2. 



after this concentration is reached. For calcium chloride the approximate elevations 

 obtained by successive additions of 10 grammes of salt to 100 grammes of 

 water are 1-58°, 1'90°, 274°, 3'08°, 3'80°, 4*42°, 4-4°, 3*04°, 2-30°, and T82°, 

 which show that per 10 grammes of salt added there is increase in elevation to 

 a maximum, and decrease after the maximum is reached. The curves for lithium 

 chloride, lithium bromide, lithium iodide, and strontium bromide indicate corresponding 

 increase and decrease. On the other hand, the curves for potassium iodide and lithium 

 sulphate are almost straight lines up to high concentrations ; that is, for such salts 

 elevation of the boiling point increases steadily with concentration. Consequently the 

 observations which have been made show a decided difference between salts. 



