472 Journal of the Asiatic Society of Bengal. [September, 1910. 



A specific gravity bottle of 50 cc. capacity was used in 

 both sets of measurements and the temperature of the solution 

 in the bottle was allowed to remain constant for at least 10 

 minutes in each case, before cooling and weighing. The 

 balance used was capable of giving a much greater accuracy 

 than was actually required. 



The acid employed in these tests was a specimen taken 

 from a jar of pure acid recently sent out from England by 

 Messrs. Cromnton & Co.. for filling a new storage battery. 



Method of calculating the density. 



Let A 8 be the density of the solution at 6° C. 



Let M e be the mass of liquid which fills the bottle at 9 C 



Let ¥« be the capacity of bottle in cc. at 0'C. 



Then 



±9 





But if 0000024 be taken as the cubical expansion coeffi- 

 cient of glass, we have, 



V, = V 16 {1 + -000024 (0—15)} 

 Now the bottle used contains 50 cc. at 15 C, so that 



V a = 50 + •0012(0— 15) 

 = 49-982 + -00120 



Th eref ore 



±9 



M e 



49-982 + -001 2 



Results . 



Since the actual numerical values obtained are of little 

 interest in themselves, curves have been constructed which 

 exhibit the results clearly and at the same time allow correc- 

 tions to be made graphically for any temperature within the 



Figu 



40 



for a 22-2% solution of acid. 



Figure 2 shows how the density of an acid solution at 

 25-2° C. varies with the percentage composition. 



