Ooubia boltoin 



Fi.ff. 62. "Vooden Tank v;ith oxygen apparatus of the firm of ICraiss L Friz. 



The oxygen-needy trout are nowadays shipped only with a supply of artificial oxygen. 

 Steel oxygen flasks of about 3 to 7 liters (0.6 to 1.85 gal.) capacity, which are mostly 

 filled with 100 to 150 atmospheres of oxygen are fastened, by means of iron holders, in 

 the standing barrels and tanks (mostly of capacities of 50 to 150 liters, 13.2 to 39.6 

 gallons), see Fig. 62. Complete oxygen barrels may be gotten from Draegerwerk, in Luebeckj 

 Kraiss L Friz, in Stuttgart, Keckar St. 182j Pass i Co., '.Veidenau, Sieg. Special cars 

 •.Yhich are suitably provided with four containers 250 x 90 x 100 centimeters (98 x 35 x 39 

 inches), but whose use only pays vdth the transportation of at least 1,200 kilograms 

 (26/;.0 pounds) of trout, are obviously today provided vdth oxygen equipments. The oxygen, 

 az'ter the pressure has been reduced by a pressure reducing valve, flows out through a 

 di rfuser, of charcoal or other patent composition (to give the greatest possible porosity 

 or surface), v;hich is protected by an iron protection basket against obstruction by mucus. 

 It enters the v.ater in a misty state of subdivision on the floor of the barrel. In 

 rising up to the surface, the oxygen streams through a relatively large layer of v/ater, 

 in v;hich it is for the most part dissolved. 



At the beginning? of transportation the oxygen flask is turned on sufficiently so that 

 the oxygen flo'/.'s out about 20 liters (3.28 gal.) per hour . Until sufficient experience 

 has been accumulated, this amount can be determined by determining the o>:ygen pressure 

 reduction in the flask. The amount of oxygen in the flfl.sk is equal to the volume of the 

 flask, multiplied by the oxygen pressure read off on the manometer. Screw threads must 

 not come in contact v.lth fat or fire. In a 120 liter (31.7 gal.) barrel v;ith a trans- 

 portation duration up to 15 hours at 5 to 6''C, about 25 kilograms (55 pounds) of table 

 trout or 3,000 trout firigerlings or 50 kilograms (110 pounds) of carps, and at 10°C 

 20 kilograms (A4 pounds) of table tro\it or 2,000 to 2,500 trout finger lings or AG kilo- 

 grajns {ZZ pounds) of carps can be shipped. Too much Qx;.'gen must not be given in any 

 case, since the resistance pov;er and storage power of the fishes suffer thereby. Trout 

 brood and stock fishes must be shipped v/ith oxygen under very special precautionary 

 measures, othei".vise gas-bubble disease, strong sliming of the skin, etc., occur. 



The shipment vdth artificial oxygen production from hjndrogen peroxide vdth the patent- 

 ed oxygen producer "liralena" of ^he Cxysana Company in IJov/awcs near Potsdam ('.Vundsch, 

 Czensny, Leh-nann), perhaps has a future in many cases, iieanvhile numerous experiences vdth 

 this ar-paratus muLt first be gathered before it can be recommended generally for practdcal 

 use. A heavy egg-shaped bottle filled v.-ith highly concentrated h^'i-lrogen peroxide is laid 



186 



