One of the Pink Panther movies finds Inspector Clouseau disguised as a local dentist who is summoned by an unsuspecting and villainous Chief Inspector Dreyfus to extract a bad tooth.   An accidental release of laughing gas puts both characters into hysterics; possibly one of the best-humorous scenes in movie history.  UPI.com reported that nitrous oxide, often used as a dentist’s anesthetic, has become the largest ozone-depleting substance emitted from human activity.  Laughing gas is produced by natural and human-related sources and is a by-product of agricultural fertilization and microbial action in wet tropical forests.  Science magazine recently reported that a study by NOAA indicated that emissions of N2O have eroded the ozone layer and is expected to continue this Century. Closing with an archived column from eight years ago on this date..."Water droplets suspending in the atmosphere is fog.  Fog that hides less than six-tenths of the sky is ground fog. I received an e-mail from Tom Kent who served with the 92nd Airborne Division’s glider regiment during World War II.  His 28 months in Europe included service in Naples, Italy and Cologne, Germany until 1945.  As a Jeep driver, a weekend pass placed Tom and his buddy in Luxembourg. The standard operating procedure for marching in fog dictates staying within three feet of another soldier but driving in it is different. On this occasion, the fog was so thick, during the return daytime trip to Cologne, that Tom watched headlight reflections on the side of the Jeep to stay on the road. Thanks for your service Tom and the note."