of Edinburgh, Session 1884-85. 
37 
Hydrometer Reading, 
Temperature of Water (tf' 2 ) and its correction. 
Density at t\ (1). 
Density at t\ (2). 
Mean density (of 1 and 2) at t' (mean of t'j and t' 2 ). 
Density at 15° ’56 (specific gravity, water at 4° being unity). 
Calculated value of Chlorine ( f ) 
Permilleage of Chlorine found (f). 
Alkalinity. 
The numbers of the first six entries are put down in the book 
as read off the instruments, the others are copied from the calcula - 
tion book. 
Ill order to get some idea of the accuracy of the method — that is 
of the exactness of the readings, the correctness of the tables, and 
the accuracy of the calculations — the following determinations of the 
density of distilled water were made. The temperature was varied 
by the addition of hot distilled water. 
I. Temperature varied from 4 ° ‘5 to 4° *6. 
Weight 4. Weight 6. Weight 7. 
1-000022 1-000017 1-000014 
Calculated, 
Difference, 
II. Temperature varied from 4° - 6 to 4° ’9. 
Mean. 
1-0000175 
0-999997 
0-000020 
Weight 4. Weight 7. Mean. 
1-000019 1-000010 1-0000145 
Calculated, 0 "999995 
Difference, 0 ’000019 
III. Temperature varied from 1 4°*9 to 14° -2. 
No Weight. I Weight 4- Weight 7. Mean. 
0-999154 0-999331 0-999313 0-999299; 
Calculated, 0 ‘999253 
Difference, 0 -000040 
IY. Temperature varied from 11° -9 to 1 1°*4. 
Weight 4. Weight 7. Mean. 
0-999725 0-999731 0*999728 
Calculated, 0-999538 
Difference, 0-000190 
Mean of four determinations, 0'9997648 
Mean of calculated densities, 0-9996982 
Difference, 
0-0000666 
