X-Nico

unusual facts about perforation


Perforation

Film stock is perforated to allow it to be moved precise distances at a time continuously.


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perforation |

Esophageal food bolus obstruction

Historical treatment of food bolus obstruction included administration of proteolytic enzymes (such as meat tenderizers), or even acidic substances, such as Coca-Cola with the purpose of degrading the meat that was blocked; however, it is possible that these methods may increase the risk of perforation of the esophagus.

Walter Dorning Beckton

Beckton was one of the Manchester School of philately which advocated the scientific study of all aspects of stamp production including paper, watermark, printing and perforation.


see also