VOL 



lxxl] 



PHILOSOPHICAL TRANSACTIONS. 



11 



By continuing these mixtures till I found the mathematical specific gravity and 

 that by observation nearly to coincide, I was enabled to draw up the following 

 table, in which if any errors be found, I hope they will be excused, from the 

 impossibility of avoiding them where the weights must be found with such ex- 

 treme precision: the two first series were only found by analogy. 



The intermediate specific gravities may be found by taking an arithmetical 

 mean among the specific gravities by observation between which that sought lies, 

 and noting how much it exceeds or falls short of such arithmetical mean; and 

 then taking also an arithmetical mean among the mathematical specific gravities 

 between which that sought for must lie, and a proportionate excess or defect. I 

 have added a column of attraction of the nitrous acid to water, as far as it keeps 

 pace with the increase of density, but no further, as I am unacquainted with 

 the law of its further increase. The specific gravity of the strongest spirit of 

 nitre yet made is, according to Mr. Baume, 1.500; and according to Mr. Berg- 



c 1 



