A SEALING STONE JAR FOR ZOOLOGICAL 
LABORATORIES. ! 
J. B. JOHNSTON. 
THE jar described below was designed as a cheap sealing 
jar for class use and for the storage of large specimens or of 
material in quantity for future use. It has been in use since 
1898 in three universities in this country, and is now described, 
since it has proved more satisfactory for the purposes indicated 
than any other jar known to me. Its cost is inconsiderable 
when compared with that of glass jars of equal capacity. It 
has the additional advantages of greater poe 
durability and ease of opening and resealing. $ 
The accompanying sketch shows a vertical sec- 
tion of the upper part of the wall of the jar (W) 
and a part of the cover (C). The rim of the jar 
bears a groove (Q) to be filled with a sealing fluid, 
indicated by the horizontal shading. The rim (X) 
or edge of the cover projects well beyond this groove 
to keep out dust. There is upon the under surface 
of the cover a dependent flange (7) fitting into the groove (O), 
so that when the latter is filled with a fluid the jar is sealed. 
The cover is provided with a knob for lifting, and the rim of the 
jar, with handles (77). 
The jars are made by the Zanesville Stoneware Company, 
Zanesville, Ohio, in the following sizes, inside measurement in 
inches : 
peph . < i 0 8 I2 I2 24 
Diameter . . ro I2 IO 12 I2 
I have tried a number of sealing fluids before anything 
suitable for permanent sealing was found. For daily class 
use it is sufficient to fill the groove with water. Indeed, the 
mere empty groove reduces the rate of evaporation very con- 
siderably, since the alcohol or other vapor must pass downward 
