I 
320 ON THE VARIOUS APPLICATIONS OP GUTTA PERCHA. 
water, in cases of impure gntta percha, being mixed with 
a solution of common soda or chloride of lime. It is next 
put into a masticating machine, such as is used in the manu- 
facture of caoutchouc, and then pressed through rollers; thus 
being connected into sheets of various widths and thickness. 
When necessary, the sheets are again masticated, and again 
passed througli rollers. These sheets are subsequently cut 
into boards with vertical knives, placed at the further end 
of the table, along which the sheets are carried by a cloth or 
web to another roller, round which they pass, and are cut 
into the required widths. The bands or straps are then re- 
moved and coiled up ready for use. Driving bands for 
machinery are thus made, and shoe soles and heals are 
stamped out of similar sheets of gutta percha. In making 
tubes or pipes, either of gutta percha or any of its compounds, 
a mass of gutta percha, after being thoroughly masticated, 
is placed in a metal cylinder furnished with a similar piston, 
by which it is pressed down into an air-box, kept hot by 
steam, which has at its lower end a number of perforations, 
through which the plastic material is forced into a cup, 
whence it passes out, round a core, into the desired tubular 
form, and thence through a gauge to the required size, and 
into a receiver of cold water, being drawn to the other end 
of a long trough by a cord passing round a pulley at the 
far end of the trough, and returning to the person in atten- 
dance on the machine, who gradually draws the pipe away 
from the air machine. Thus tubes of considerable length 
and diameter are made to a very great extent, and are used 
for the conveyance of water and other liquids, and are now 
under test for the conveyance of gas. The paper next ex- 
plained the variety of articles already made of gutta percha, 
which were of three classes— -1. Useful. 2. Ornamental; 
and 3. Useful and ornamental combined. Various articles 
were then exhibited, including two very handsome shields, 
and a splendid communion dish and service. Mr. Whishaw 
next exhibited the Telakouphanon, or Speaking Trumpet, 
