[. Gp J 
Tue precipitated calx, edulcorated and expofed to a red heat 
for three quarters of an hour, weighed 30,5 grs. or rather 31,. 
(as that flight lofs may be prefumed during the edulcoration.) 
This calx was of a deep red colour, and as fuch calx affords 
about 72 per cent of iron, thefe 31 grs. were equivalent to 
22,3 of metallic iron. 
Hence the proportion of ingredients in 100 parts cryftallized 
vitriol of iron are,. 
Iron - - - > 22,32 parts. 
Standard acid ~ - - 29,21 
Water united to the ftandard acid - 9,47 
Water of cryftallization - - 39,00 
100,00 
HENCE 100 parts iron require 130,85 of the vitriolic ftandard 
for their folution. 
Accorpinc to Mr. Bergman, too parts vitriol of iron contain 
23 of iron, 39 vitriolic acid, and 38 of water of cryftallization. 
THis account may eafily be reconciled to mine, by fup- 
pofing what is certainly true, that what he calls the acid part, 
is not of the fame ftrength as the part that is fo called in 
tartar vitriolate, but is only that part which does not include the 
water of cryftallization. For if we add the 9,47 parts water 
Vo, IV. K united 
