Bauhaus-Universität Weimar

Reports of Visits to Foreign Laboratories, vol. 2 (1910) [Illustrated Typoscript in 7 volumes] Reproduced with the kind permission of Dr. Cecil E. Leith
Benedict, Francis Gano
An improvement over the original system of Pettehkofer and Voit is a 
mercury valve which checks the rate of working of the valve. 3y means of a 
screw at the bottom, the level of the mercury can be rasied somewhat and in 
this way a greater resistance to the passage of the air current made. These 
screws and the valve arrangement are shown in Pig. 42. A small sketch of 
this regulator is given in Pig. C. 
The small mercury pump, with the Voit valve used for carrying the air 
current through the small sampling meters, may be seen in Pig. 43, at the 
extreme right of the mercury valve regulator just mentioned. An ingenious 
clamp is also used by Voit to hold the barium-hydroxide tubes, and if one 
were to employ this method, Voit's new clamp should certainly be used. 
One of the chambers is completely surrounded by a water mantle (see Pigs. 
44 and 45) so that experiments can be made at different temperatures, a petro¬ 
leum regulator in the bath regulating the heating of the water. The same 
general type of petroleum regulator is used in other places in the labora¬ 
tory, as, for instance, for holding a bath at a constant temperature of 15°, 
for keeping the water at a constant temperature in calibrating burettes, and 
for keeping standard solutions at a constant temperature. This use of a con¬ 
stant temperature is typical of many of Erwin Voit's methods for recording 
temperatures. He is extremely accurate and extremely precise. 
The gas meters are calibrated by means of water, before and after each 
experiment, and as previously stated, Professor Voit finds them extremely 
accurate. As a matter of fact, in analyzing the ingoing air, room air is 
used and Professor Volt sees no reason to think that it might be better to 
use outdoor air. These gas meters are calibrated and a description of the 
method of calibrating was given by Voit is a paper in the Zeitschrift f. 
Biologie, 3d. XXII, p. 281, entitled "Ueber die Aichung der Gasuhren". Pro¬ 
fessor Voit has sent us a copy of this. 
Laboratory construction.- I found much to interest me in the laboratory, 
the construction of the hoods being very good indeed. Structural steel is


Sehr geehrte Benutzer,

aufgrund der aktuellen Entwicklungen in der Webtechnologie, die im Goobi viewer verwendet wird, unterstützt die Software den von Ihnen verwendeten Browser nicht mehr.

Bitte benutzen Sie einen der folgenden Browser, um diese Seite korrekt darstellen zu können.

Vielen Dank für Ihr Verständnis.