16 - JOURNAL OF THE 
suffice. There will be little loss of zirconium if fust 
enough acid is used each time to bring the soluble chloride 
into solution (some little insoluble chloride is nearly al- 
ways present.) The acid poured off each time from the 
crystals may be saved and evaporated to recoyer the zir- 
conium or used in the decomposition of other portions of 
zircons. 
‘II. ZIRCONIUM CHLORIDES. 
Large number of compounds of zirconium with chlorine . 
or chlorine and oxygen have been described and these 
compounds have been the subjéct of much investigation. 
The object in many cases has been to secure a zirconium 
chloride of definite composition which would prove a.val- 
uable compound for determining the atomic weight of the 
element. ‘Thére are several difficulties in the way of se- 
curing such a conipound. 
1. The tendency to form basic chlorides. 
2. The ease with which hydrochloric acid is lost 
through the action of heat and of dehydrating agents. 
3. The presence of free hydrochloric acid. 
4, The deliquescent nature of the chlorides. 
It is particularly desirable that the conditions under 
which a definite chloride can be formed should be discov- 
ered, as zirconium seems to yield no very satisfactory 
compounds for, the determination of the atomic weight. 
There have been many efforts at finding out these exact 
conditions. 
Most text-books state that anhydrous, pure zirconium 
tetrachloride can be prepared by passing dry chlorine 
over a mixture of charcoal and zirconia heated toa high 
temperature. Hermann used this sublimed zirconium 
chloride for the determination of the atomic weight. As 
Clarke says, however, little confidence can be placed in 
his results. Bailey (Chem. News., 60, 17.) has recorded 
that even with great care to avoid the presence ot moist- 
ure he was unable to prevent the formation of oxychlo- 
’ 
