H. Wurtz on the Preparation of Pure Sulphates. 369 
move also entirely the sulphate of lime bei usually contami- 
hates commercial Epsom salt; for, as I have there stated, car- 
bonate of baryta totally precipitates ype from its solution, 
even in the cold; and I have there proposed it as a means of 
removing the ep Ph from spring or sea-water which is to be 
used in steam boilers, (thus a nhsineS inerustations) as well as 
from the brine of salt works. I hav ce found that carbonate 
of lead has ad same power of paenipnalalg gyP psum, and may 
an carbonate of 
aryta, donsideritig the facility with which the lead may be re- 
covered from the resulting mixture of sulphate of lead and car- 
bonate of lime, in a metallic form. * 
* Although not wholly relevant to the subject of ses per, I may be pardoned 
8 few additional remarks s upon this subject of the removal of gypsum from waters. 
When we call to mind that the crystallization of the st um from its hot solution 
is the prin ipal, and usually the only cause 0 "the formation of the destructive 
nd that, leavi 
show 
France), in Hen cases to 40 per cent of the fuel consumed, the subject may be con- 
wo 
ations bsing- 2 ste it. 
In a saturated solution of gypsum then (say. in round nnmbers, 1 part in 400) each 
800 Ibs. = 800 pints = 100 gallons will contain 2 tbs., and each 10:00 gallons 20 tbs. 
of sulphate of lime ; which is equivalent to 24 tbs. of pure carbonate of baryta, or 
31 tb pure carbonate of lead. wat fe 
i pe is seldom or lution of gypsum. Let us 
ae eee oie of the yeas of Aas pepe Ocean, (Lieb Saupe 
‘ = f Lackawanna anthracite (co! in 
. =) we “ae that 1 Ib, for ee “ ps a 
8X 100.000 
80 that to evaporate 100,000 poniie would require sepa heals ==94,000 Ibs., or 47 
tons. ch tty is over 18 to 
Ido ae however, Sy any means 5 d the. ao nar gare of this Ke gimen.aieg to 
an steamers, account of practical iets which I see no way to yt 
on land the application is a matter of pe Hae licity. ae pag h 7. = 
to aes the tanks from w the bailer, is supplied, larger, pet ore 0} 
— While the process of mixture guy ae ; 
10 b . . . in one r é 
= = sey a i seems to me to be especially applicable to 
locomotives, for which even sea-water may then be used. 
‘SECOND SERIES, Vor. XXVI, No. 78.—Nov., 1858. 
48 
