A O/'A'AM V70AX

Oxidation in the Crucible.......The crucible is ulnuwt invariably

heated by means of a naked flame, being supported on a tri-
angle l>y means of some* kind of .stand. When the obji*ri in fi*

Mi'thmi of

u fiii««r i»H|t«'r for iKuifi*«fi

oxidize t.licv paper or precipitate ih«» erueibh1 is jiluee<l

and the rover leaned against it us shown in Fig. 10.

is placed und(»r the bottom of the rrueible. in sueh a jM

the gaseous products of the

burner cannot- enter the* cruci-

ble. The uprising current, of

warm air strikes the cover

and is deflected into the cruci-

ble, thus providing an oxidise-

ing atmosphere about-, the

paper. If the flame from the

burner IH applied only enough

to keep the paper burning

the desired condition i.;

attained. Xo harm result,'*

if the* volatilized combustible

material from the paper

burns with a flame abovi*

the crucible. After the puf

5s thoroughly charred th

on
he

Ifn Hide
hurwr

thiit

temperature* is gradually

rained to complete! the? eons-4

buHtion. Fi(*< !<l' i'''-p''» ••»

The proper* position of the?
crucible on the triangle* IK nhown in Fig, 11.

r

If

4 - • !*

Fig, 12 the cnidl>le is liable to fall buck and It nmv
times fall through and CAIIHI* a failure of the det«

f