Permanent Collection Objects

Juneau—Douglas City Museum

2007.22.057A—E

2007.22

Transferred from the U.S. Bureau of Land Management.

Desiccator

1950

1996

Desiccator
A: Glass bowl. The base is narrow then the top. The base goes straight up then widens at about 2 inches and continues to go straight up until the lip fans out.
B: Cover
Glass dome with flat lip. Sits onto of desiccator (A). On the top it says"PYREX T.M REG. U.S. PAT. OFF. MADE IN U.S.A." In the middle of the lid, there is a column that the stopcock fits into.
C: Stopcock
Glass tube with bowing in the middle. In the bowed area there is a stopper through it that allows air in or keeps it out — the green clip (E) attaches to the base of this. The stopper has a hole through the middle that will allow air in or keep it out. Below the stopper is a black rubber stopper to make the seal with the lid (B) airtight.
D: Plate
White ceramic plate that fits into the bottom of the decisteres. There are three rings of small holes in it and a larger one in the middle.
E: Clip
Small green double—fold metal clip that fits onto the stopcock. There is a 'U' shape cutout in the middle.

Used in the mineral analysis process. Used to remove all moisture from a rock sample. A water absorbing substance is placed in the bottom of the desiccator. Then the plate is put in. The sample is put on the plate. The whole thing is sealed and the stopcock is closed. There is a substance, such as petroleum jelly, put on the rim between the cover and the bowl to seal it and thereby create a vacuum inside.

Mining
T&E
JMIC
Assaying