336 



PROCEEDINGS OF SECTION B. 



The conversion to actual quantities shown in the last column is made 

 by using the following factors : — 



As a check upon the method an analysis may be made by any of the 

 older methods. So far as boiler waters are concerned, the crucial test is 

 in the magnesium. In the example quoted the magnesium, as directly 

 determined, was 5-31, while the result obtained by calculation from the 

 Hmg = 22 X -244 = 5-37. 



Notes. — In selecting this mode of analysis a large number of sugges- 

 tions were experimented upon. For instance, the total hardness may be 

 obtained directly by making the titration in determination 1 to exact 

 neutrality, boiling off the CO2, adding excess of N/ioNaoCO.,, and con- 

 tinuing as in determination 2. In this case the total hardness = 

 5 (N — n). This may be used as a check on the other determinations. 

 Again, it has been suggested to determine the Hmg directly by means of 

 lime vvater ; but this, and a scheme for treatment calculations based upon 

 a lime factor in which lime water is used, failed to give satisfactory re- 

 sults in practice. These were not abandoned without regret, for they 

 seemed very promising and appeared to further simplify the analysis. 



Slight modifications in detail have been tested. The only ones, 

 however, that \Ye found equally as satisfactory as the method to which 

 preference has been given are in determination 2. These modifications 

 are — 



(«) Boil 140c.c. of the water with considerable excess {i.e., at least 

 60c. c. in one and 80c. c. in the other) of N/ioNajCOa, for half an hour 

 or) until reduced to small bulk) ; cool, and transfer to 200c. c. flask and 

 make to mark with cold recently boiled distilled water ; mix thoroughly 



