[ 463°-1] 
whole was reduced to half a fpoonful I found that 235 grs. of 
the folution of lead had been employed; the refiduum evidently 
contained vitriol of lead, as it appeared to form a pellicle on the 
furface of the liquor. 
Now fince 623 grs. of the folution of lead contained 30 of 
lead, 235 grs. of this folution muft have contained 11,31. And 
fince in vitriol of lead 70 parts lead indicate the prefence of 30 
of the ftrongeft vitriolic acid, (in which ftatement both Mefits: 
Bergman and Wenzel agree), the prefence of 11,31 gts. of lead 
indicate the prefence of 4,84 of this ftrongeft acid. We have 
already feen that the ftrongeft vitriolic acid is to the ftandard 
acid as 82 to 92, then 4,84 grs. of this acid are equivalent to 
5,4 of ftandard, which is ftill far below the truth. 
As to the quantity of earth, Mr. Wenzel found. by precipitating 
the earth contained in an ounce of allum by a fixed alkali, that 
it amounted when dry to 140 grs. that is 30 per cent. as I had 
done., But in a ftrong heat continued for two hours the whole 
was reduced to 90 grs.; then 100, parts allum fhould contain 
neatly 19 per cent. of earth. Then the 29,78 grs. which exifted 
in the degree of deficcation I employed might be reduced to 19. 
For 140. 90::29,78.19 nearly*. 
of 
* From the proportions here rigoroufly determined, it appears that fome of the 
pofitions in my late paper on the alkalies ufed in bleaching are not exact. 
