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Of the Vitriolic Acid, 
Ir was obferved to me fome years ago by the very able and 
candid philofophic chemift, Mr. De Morveau, that the denfities 
accruing to mixtures of this acid with water, greater than found 
by calculation, fhould principally be afcribed to the condenfation 
of the aqueous part, rather than to that of the acid part, as I 
had done. I felt the juftice of this obfervation, which fubverted 
the inferences on which I had grounded my former calculations. 
I was, however, much embarrafled to find a more unexception- 
able method of forming tables on’ which I was fenfible much 
of the precifion requifite in chemical analyfes depended, until 
I attended to Mr. Pouget’s curious letter, lately read to the 
Academy *. I neither could make nor procure oil of vitriol 
whofe fpecifi¢ gravity is 2,000 in the température of 66°. 
Yet in cold climates this acid has frequently been produced ; 
and as it is the ftrongeft or nearly fo than ¢an be exhibited 
by art, f take it as the ftandard of the ftrensth of all other 
acids of this kind. From the multitude of experiments I have 
made with acids of inferior denfity, as 1,8846, 1,8689, 1,8042, 
7 5005 I, have reafon to think that the condenfation of equal 
weights of this ftandard acid’ and water amounts to of the 
whole. Then by the applications of Mr. Pouget’s formulas for 
inveftigating the accrued denfities of inferior proportions -of 
acid and water, the fucceflive increments of denfity will be 
found as follows : 
Parts 
* And now publifhed in the Tranfactions for 1789. 
