[ 66 ] 
united to the ftandard acid to the 29,21 of flandard, we {hall 
have 38,68 of an acid, whofe fpecific gravity is 1,7178. 
Mr. Wenzel gives no account of the compofition of vitriol, 
but barely relates that 240 grs. of bis fpirit of vitriol diluted 
with 240 of water diflolved 55,25 of fteel Now we have 
already feen that 240 grs. of his fpirit of vitriol contain 84,19 
of my flandard, and hence it would appear that 100 parts fteel 
fhould require for their folution 152 of vitriolic ftandard. 
This feeming deviation from my refult is to be attributed to 
his having expofed to the action of the acid a larger proportion 
of iron than it could diffolve, the undiffolved part neceflarily 
retained a portion which he could not eftimate. 
To diffolve iron rapidly the quantity of water fhould be to 
that of the ftandard as 5 to 1; if it exceeds the proportion of 
7 to 1 the folution will be very flow. 
Of the Quantity of real Acid in the different Standards. 
By real acid, I do not mean an acid abfolutely divefted of 
all water; perhaps water may be effential to the acid properties 
of all acids, as it certainly is of fome of them; I barely 
denote by that appellation the ftrongeft acid known to exift, 
whether in a combined or in a feparate ftate; for inftance, the 
vitriolic acid, as it exifts in tartar vitriolate; by recurring to the 
obfervations 
