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
Tangible symbol systems of communication for individuals who are unable to understand or communicate using abstract systems, such as speech or sign language. Properties of tangible symbols include permanency, capacity to be manipulated by both the user and the communication partner, and an obvious relationship between the symbol and the referent. They can represent items, people, activities and/or events, and look or feel similar to what they refer to. For example, a cup can be used as three-dimensional tangible symbol to represent the action: "drink". A photograph of a cup can be used as a two-dimensional tangible symbol to also represent the action