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
Non-logical symbol over the signature mentioned above is the ordered group of integers. Its domain is the set formula_1 = {…, –2, –1, 0, 1, 2, …} of integers. The binary function symbol + is interpreted by addition, the constant symbol 0 by the additive identity, and the binary relation symbol < by the relation less than. Outside a mathematical context, it is often more appropriate to work with more informal interpretations. Rudolf Carnap introduced a terminology distinguishing between logical and non-logical symbols (which he called "descriptive signs") of a formal system under a certain type of interpretation, defined by what they