The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Lieutenant Colonel (Chemical Corps) Gilbert N. Lewis, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I. By his unusual energy, marked ability, and high technical attainments, Lieutenant Colonel Lewis rendered extremely valuable service by securing first-hand data on the use and effects of gas and submitting reports of such value that they became fundamentals upon which the gas-warfare policies of the American Expeditionary Forces were thereafter largely based. Later, as Chief of the Defense Division, Chemical Warfare Service, he obtained a high state of efficiency in the protection of our officers and soldiers against enemy gas and furthered the successes of American arms by securing a better and more effective use of gas, especially mustard gas, against the enemy, thereby rendering services of great value to our Government.