INDUSTRIES DEPENDING ON ANIMAL PRODUCTS 1845 



egg when put into store, it is of the first importance that cold storage 

 warehouses be established in the very centres of production so that all 

 transport of fresh eggs be minimised as possible. 



4) Sterilization in closed vessels. — In order to preserve eggs in a 

 perfectly fresh and wholesome condition, it is necessary to combine cold 

 storage with a preliminary sterilization such as is practised in the Lescarde 

 method which was making great headway in France before the war. By 

 this method the eggs are exposed in closed vessels to an atmosphere consist- 

 ing of carbon dioxide and nitrogen, and this together with a low temperature 

 is sufficient to destroy bacteria and moulds in a short time and to ensure 

 the subsequent preservation of eggs over a long period. Details of the 

 process a.o as follows : 



On arrival at the factory the eggs are unpacked and tested in order 

 to discard all stale or cracked eggs. The testing is carried out with a simple 

 apparatus consisting of a sheet of cardboard pierced with 168 holes each 

 destined to hold an egg in a vertical position. The cardboard is held in 

 a wooden frame fixed on to an empty wooden case lined with metal sheet- 

 ing. There are two electric bulbs inside the case and the testing is carried 

 cut in a dark room so that it is easy to see the rays passing through the 

 eggs and to distinguish rotten or spotted specimens. For each million eggs 

 handled, 2 of these testers are required. 



After being tested the eggs are transferred to a cooling room where 

 they are packed into metal cases. Each case contains 6 trays and holds 

 1000 eggs. Cavity walls preserve the contents from bumps and an outer 

 covering of wood facilitates the handling of the cases. As each case is 

 filled a little calcium chloride is sprinkled inside to dry the air, and the lid 

 is soldered on to the case, taking care that a small round hole of 5 mm. 

 diam. is left open in the lid. The cases are loaded on to a truck and run 

 into an autoclave very similar in construction to that used for creosoting 

 railway sleepers. There the chamber is first exhausted to get rid all oxygen 

 — both a ,mo.spheric and dissolved in the egg albumen and — then carbon 

 dioxide is then run in through a coil plunged in warm water so that the intense 

 cold of the gas as it issued from the cylinder should not crack the egg shells. 

 When the pressure inside the chamber is equal or slightly above that of 

 the atmosphere, the flow of carbon dioxide is stopped, the saturation of 

 the eggs with carbon dioxide being assured as soon as the manometre be- 

 comes steady. As there might be some risk of the carbon dioxide having 

 a solvent effect on the albumen during storage, the pressure of the gas in 

 the autoclave is watched carefully and as soon as it goes above a certain 

 point, carbon dioxide is pumped out and replaced by nitrogen (compressed, 

 sterilized and cooled to 15° C), the mixture adju.sted so that it remains 

 sufficiently antiseptic to ensure sterilization without attacking the albumen. 

 As soon as this has been accom])lished and the egg liquids are saturated 

 with nitrogen, the autoclave is opened, the truck drawn out, and the openings 

 in the lids of the cases are quickly sealed. A small solder plug is used for 

 the purpose and it is coated over with a mixture of oil and grease. No 

 danger of infiltration of air during the operation need be feared as the 



