U.S. Marines standing in ranks with gas masks attached. France, 1918. The first use of poison gas on the Western Front was on April 22, 1915, by the Germans at Ypres, against Canadian and French colonial troops. The British Royal Society of Chemistry claims that British scientist Edward Harrison developed the first practical gas mask for mass production towards the end of 1916. American chemist and inventor James Bert Garner is credited by American sources with the invention of the gas mask in April 1915. He remembered experiments he had performed while teaching at the University of Chicago, thus he set about creating the first gas mask which he tested on two of his associates in a gas filled chamber. Following the successful completion of the test, he provided the results to the British government. Since dogs were frequently used on the front lines, a special type of gas mask was developed that dogs were trained to wear. Additionally, gas masks were developed during World War One and the time following for horses in the various mounted units that operated near the front lines.
