Chemical Corps affiliation with the corps. The Chemical Corps branch insignia consists of a cobalt blue, enamel benzene ring superimposed over two crossed gold retorts. The branch insignia, which was adopted in 1918 by the fledgling Chemical Service, measures .5 inches in height by 1.81 inches in width. Crossed shells with a dragon head was also commonly used in France for the Chemical service. The Chemical Warfare Service approved the insignia in 1921 and in 1924 the ring adopted the cobalt blue enamel. When the Chemical Warfare Service changed designations to the Chemical Corps in 1946 the symbol was retained. The regimental
Au pair other adult caregiver is also home and fully responsible for the infant. The Au Pair Program is administered by the US Department of State. Participating families and au pairs must work with one of the currently 12 approved agencies. Au pairs enter the United States on a J-1 visa. According to the Internal Revenue Service, an au pair will almost always be a nonresident alien, and will be required to file a tax return on Form 1040NR or Form 1040NR-EZ to report his or her au pair wages. These wages, however, are not usually subject to social security and Medicare