Glenbrook Tunnel War One. The first was Chlorine gas which was introduced by the Germans at the Second battle of Ypres in April 1915. This was followed by the use of Phosphene Gas, also introduced by the Germans. These attacked victims' respiratory organs causing coughing and choking. The Germans used Mustard Gas, a more advanced gas, for the first time at Riga (or Yperite) in September 1917. It caused both internal and external blistering in its victims. The blistering was often delayed and remained in the ground for weeks afterwards making capture of infected trenches dangerous. Protection against mustard gas was far
18th Army (German Empire) 18th Army (German Empire) <nowiki></nowiki> The 18th Army () was an army level command of the German Army in World War I. It was formed against France on 27 December 1917 from the former Heeresgruppe Woyrsch command. It served exclusively on the Western Front and was dissolved on 2 January 1919. 18th Army was one of three armies (along with 17th Army and 19th Army) formed in late 1917 / early 1918 with forces withdrawn from the Eastern Front. They were in place to take part in Ludendorff's Spring Offensive. The Germans had realised that their only remaining chance of