Whereas carbon renders isomerism possible in organic compounds, cobalt and platinum are the determining elements in inorganic chemistry, the phenomena being exhibited especially by complex ammoniacal derivatives.
A further distinction is necessary to a survey of the subdivisions of isomerism regarded in its widest sense.
The phenomenon of isomerism will probably supply the crucial test, at least for the chemist, and the question will be whether the Ostwaldian conception, while substituting the Daltonian hypothesis, will also explain isomerism.
In this case it is readily seen that isomerism introduces itself in the three carbon atom derivative: the propyl alcohols, expressed by the formulae CH3.
This kind of isomerism has been denominated stereoisomerism (q.
Before entering into detail it may be useful to consider the nature of isomerism from a general standpoint.
The conception of metamerism, or isomerism in restricted sense, has been of the highest value for the development of our notions concerning molecular structure, i.
Certain investigations on isomerism which have become especially prominent in recent times bear on the possibility of the mutual transformation of isomers.
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.
The development of stereo-isomerism at the hands of J.
Another form of isomerism is occasioned by spatial arrangements, many of the reduced terephthalic acids existing in two stereo-isomeric forms.
The cause of isomerism evidently lies deep within the essential conditions of a substance, and its investigation has already led to a number of results of unexpected importance and of immense scientific significance.
It is evident that the cause of isomerism here is, on the one hand, the difference of the amount of hydrogen in union with the particular atoms of carbon, and, on the other, the different connection between the several atoms of carbon.
On what are the isomerism of ozone and oxygen, and the peculiarities of ozone, dependent?
As a general name for these different classes of substances, the term "dynamic isomerides" has been introduced; and the different kinds of isomerism are classed together under the title "dynamic isomerism.
A similar behaviour is also found in the case of other isomeric substances where the isomerism is due to difference of structure, i.
Custom has to some extent restricted its use to inorganic chemistry; the corresponding property of organic compounds being generally termed isomerism (q.
Thus, some organisms seem to display a biological isomerism akin to chemical isomerism, save that the particles which in organisms take the place of chemical atoms are infinitely more complex.
A rough illustration of the phenomenon of isomerism is furnished by written language.
The word isomerismwas coined by Berzelius to express this anomalous condition of things, which seemed to negative the most fundamental truths of chemistry.
It is in such cases that isomerism is observed to occur.
The well known hypothesis of these authors was put forward to account for a certain kind of so-called physical isomerism which shows itself in the action of substances upon polarized light.
Isomerism is the term employed to represent another exceptional class of facts, observed by later chemists to interfere with the general rule, that analogy or similarity of composition implies analogy in form and external properties.
