Such isomerism, named stereoisomerism (q.v.),hasbeen assiduously developed during recentyears; it prevails among many different classes of organic compounds and many examples have been found in inorganic chemistry.
Their full significance is treated in the section of this article dealing with organic chemistry, and in the articles Isomerism and STEREO-Isomerism.
The former pointed out that the supposed isomerism was not due to an arrangement of atoms, but to the disposition of a valency, and therefore it was doubtful whether such a subtle condition could exert any influence on the properties of the substance.
Identity in composition, but difference in constitution, is generally known as " isomerism " (q.v.), and compounds satisfying this relation differ in many of their physical properties.
The aldehyde group reacts with hydrocyanic acid to produce two stereo-isomeric cyanhydrins; this isomerism is due to the conversion of an originally non-asymmetric carbon atom into an asymmetric one.