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UNIVERSITY OF COPENHAGEN
ergometer is provided for exercise. Subjects can remain in it for any desired length of time. It is our intention to use it also as a respiration chamber at ordinary pressure for the determination of the respiratory exchange of subjects during daily routine occupation.
The aquarium installation comprises two sea-water tanks below the basement with a capacity of 16 m3 each. The water to fill these tanks has been brought by steamer from the middle of the North Sea. An automatic pump will take the water from either one of the tanks up to a reservoir of 60 liters placed 3.20 m above the floor level in the room for experimental zoology shown in Figure 13; from here it flows along pipes to supply a large number of aquaria placed on the stand. These aquaria are of a new construction, made from martinite and glass in teak-wood frames. They cannot give off any harmful substances to the sea water and do not rust. The water flows from them through the shallow tank on which the stand is built, down to other tanks for the storage of larger marine animals and to the filters in the basement, whence it returns to the storage tank. The sea-water pipes and taps are of vulcanite. The main pipe is carried down into the basement and from there the sea water traverses, in iron pipes covered with asphalt, an insulated underground cellar of 40 m3 capacity in which snow is collected during the winter. The pipe lines are arranged in coils below the snow and the sea-water pipe returning from this cooling cellar will always carry water of nearly 0°C to supply aquaria at low temperature.
The cold sea-water pipe returns to the stand in the first floor shown in Figure 13. In a separate “cold” room in the basement we have an insulated tank which can be filled with sea water and connected as desired with the filters. This tank is divided into compartments of about 300 liters, each separated by double walls of thin corrugated martinite. Between the double walls cold fresh water from pipes belowT the snow can be circulated to maintain any desired temperature below that of the room.
Rain-water is collected from part of the roof of the main building. The corresponding roof gutter and drain-pipes are coated with tin. By means of an automatic arrangement the first rain only washes the roof and water is collected only after a fairly heavy shower. The rain-water is stored in a subterranean tank of 3 m3
and an automatic pump distributes it to a small number of vulcanite taps. The rain-water is used to fill up the loss by evaporation from aquaria and tanks and to prepare sea water of diminished salinity to imitate the conditions round the Danish coasts. Aquaria with diminished salinity have their own filter and local circulation by means of air pressure.
In a glass house of 4.45 by 6.0 m experiments can be made which require a great quantity of light. Sea water and rain-water are available here but without circulation. One half of the glass house is covered with “ultra-glass” permeable to ultra-violet light, the other half with ordinary glass. It seems doubtful whether there is enough ultra-violet light available in the city atmosphere to make this arrangement really useful. The temperature in the glass house can be to a certain extent automatically controlled.
Figure 14 shows a corner of the chemical laboratory with part of the fume cupboard and two small rooms for balances and chemicals respectively. These rooms have been made dust-proof. The walls and doors are as nearly air-tight as possible and the unavoidable exchange of air due to temperature and pressure variations takes place almost entirely through felt filters. A dust-proof room for storage of instruments is provided in the attic. A similar dust-proof storeroom -was used for three years in the old laboratory and has proved very satisfactory.
As seen on the plans of the floor the corridors in the northwest wing of the building arc irregular on account of the air shafts. The irregularities have been filled out by cupboards which are utilized as a general storeroom for all such implements as are frequently used in the laboratory. These are therefore directly accessible to all workers.
It is desirable finally to mention the workshop which is conducted on business principles and which manufactures for sale a number of instruments which were originally designed and constructed in the laboratory, e.g. respiration apparatus for standard metabolism, recording spirometers, bicycle ergometers, microburettes, sea-water aquaria, etc. The workshop brings in a net profit of several thousand kroner a year which constitutes a welcome addition to the budget.
Professor Krogh is director of the Laboratory of Zoophysiology.
Received for Publication February 24, 1930