58 
TUBE MOUNTS FOR EXHIBITION. 
It is often necessary to preserve material of various kinds in a 
manner that will admit of its close examination without removal 
from the fluid in which it is placed. Furthermore, the usefulness 
of such preparations increases with their portability. For several 
years the writer has used lecture demonstrations consisting of 
sections of glass tubing containing specimens in alcohol or for- 
malin, ane sealed with cork stoppers. These were found to be 
through the cork, or the pressure of the vapor forced out the 
stopper. 
In 1898 I saw some animal preparations in Professor Nach- 
trieb’s laboratory, which had been preserved by being sealed her- 
metically in glass tubes, and having learned from him the method 
of making such mounts, have found them capable of wide use in 
museum exhibits and desienstration® Professor Nachtrieb has 
found that cylindrical tubes of good clear glass are most useful in 
coca work (a description of his method may be seen in 
e, Vol. 10, p. 772, 1899), but a tube of ep cross-section is 
a preferable for most botaniell specimens. Oval tubing 
is listed regularly by one or two manufacturers in Germany, but 
it can be made to order by almost any American firm, at a cost 
of about 50 per cent. in excess of that of cylindrical tubing. The 
four sizes most useful in my own work show the following di- 
ameters : 6X 12, 10X18, 15x 23,and 20x 35 mm., and these may 
be obtained in meter lengths only. 
The specimen to be mounted must first be fixed and hardened 
by the proper method, with all of the parts in the positions in 
which it is desired to display them. Next a section of the tubing 
in which it will fit snugly is selected. One end of the tube is 
sealed and annealed by means of a blast lamp operated by means 
of a foot-bellows. It will be found desirable to seal the ends of 
the tubes in stock, and then cut off the length necessary to en- 
close the specimen. The specimen is taken from the hardening 
Q. 
a 
attention to the placing of the organs. The tube is then held 
