Laboratory of the Experiment Station.
Prof. Henriques and Dr. Hansen.
Prof. Henriques and Dr. Hansen have contributed a great deal to
our knowledge of metabolism and their laboratory is very active»
gmall respiration apparatus.—A small respiration apparatus for
mice and rates was partially mounted. Its use had not been attended
with the greatest success although it presented many interesting
points. For example, the pump used was a series of vacuuia boxes for
aneroid barometers, soldered together in such a way that by"bgjlttngT
them, there could be a suction of air. By connecting this with mercury
valves, built on the principle of the Prechsel gas washing bottle, a
regular current of air could be maintained with great ease.
Large gasometers such as were installed in Prof. Bohr's laboratory,
were likewise found here. The glass-faced gas meters were also used
and Proi. Henriques had attached a small electric counter to record
the number of revolutions of the drum.
Two experimental forms of calorimeters after the principle of
d'Arsonval and Lefevre were in a partial state of demolition. Their
use had not been thoroughly successful, as I understood it.
Kjeldahl method of determining nitrogen.—The Kjeldahl method of
determining nitrogen was developed in a brewery in Copenhagen and the
method as originally carried out by Kjeldahl himself is in use in the
Experiment Station laboratory. To the acid solution after ammonia
is distilled into is added 10 cc. of a 5 per cent solution of potassium
iodide, and then ? cc. of a 4 per cent solution of potassium iodate.