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made of silver, which had also the advantage that they could be 
readily made in any desired shape. The construction of the apparatus, 
presently to be fully described, was entrusted on the recommendation 
of Prof. H. C. Dissrrs, to Mr. Bearer of Utrecht, who has perfor- 
med his task with great skill and ability. 
Description of the Apparatus. 
The actual boiling vessels consist of cylindrical silver vessels closed 
at one end. They have a height of 20 em. and a diameter of 6 em. The 
bottom and sides walls 
consist of one piece. As 
will be seen from the 
accompanying drawing 
(Fig. I) the top of the 
silver cylinder is closed 
with a lid through 
which pass the glass 
condensing tube A and 
the thermometer C. 
This tube, shown in 
the drawing on a re- 
duced scale, has a dia- 
meter of 1 cm. and 
reaches inside the 
cylinder to a distance 
of 2 em. from the bot- 
tom. The tube is sealed 
at the bottom, but at 
its side turned away 
from the thermometer it 
is provided with three 
openings of 1 em. diam. 
Just underneath the lid, 
the tube has another 
oval opening 2.5 cm. 
long and turned towards 
Fig. 1. the thermometer. 
The holes below serve to allow the condensed vapour to mix with 
the boiling liquid, whilst the oval hole at the top serves to carry off 
the watervapour. The thermometer which is provided with an india- 
rubber ring may be connected airtight with the lid by means of a 
screw. The second small silver condenser B is 1,5 cm. wide and 
