Preparätions of Iron. 157

tory, He adds, that the fuccefs of the procefs de-pends on raifing rhe fire haflily, to prevent the SaS.ammoniac from fubliming before the greater heatenables it to carry up a fufficient quantity of iron ;that, hence, the moft proper veffel is an iron pot,to which is luted an earthen jar, having a fmall holein its bottom for the efcape of elaftic vapours ; andthat, by this method, flowers of a deep orange-co-lour often rife at the firft fublimatioü.

FERRI RUBIGO.

Rust of Iron.

Take of iron Filings one pound.

Expofe them to the air, often moifteningthem with water, untill they are corroded in-to ruft ; then powder them in an iron mor-tar, and wafh off, with diftilled water, thevery fine powder.

But the remainder, which will not by rr.o-derate rubbing be reduced into a powder ea-fily wafhed off, muft be expofed, moiftened,to the air for a longer time, and again pow-

dered