Phenazone is an isomer of phenazine, to which it bears the same relation that phenanthrene bears to anthracene.
Ladenburg (Ann., 1875, 179, p. 163) to be symmetrical trimethyl benzene; terephthalic acid, the remaining isomer, must therefore be the para-compound.
MANDELIC ACID (Phenylglycollic Acid), C 8 H 8 O 3 or C 6 H 5 CH(OH) COOH, an isomer of the cresotinic and the oxymethylbenzoic acids.
Chavibetol, an isomer of eugenol, occurs in the ethereal oil obtained from Piper betle.
Benzoflavin, an isomer of chrysaniline,1`is also a dye-stuff, and has been prepared by K.
An isomer of cinnamic acid known as allo-cinnamic acid is also known.
By the addition of the diazonium salts to a hot concentrated solution of a caustic alkali, C. Schraube and C. Schmidt(Ber., 18 94, 2 7, p. 520)obtained an isomer of potassium benzene diazotate.
Consequently, of each pair of isomers we may establish beforehand which is the more stable; either in particular circumstances, a direct change taking place, as, for instance, with maleic acid, which when exposed to sunlight in presence of a trace of bromine, yields the isomeric fumaric acid almost at once, or, indirectly, one may conclude that the isomer which forms under greater heat-development is the more stable, at least at lower temperatures.
Jorgensen in the second dinitrotetramminecobalt chloride, [Co(NO 2) 2 (NH 3) 4 ]Cl, designated as flavo - whereas the older isomer of Gibbs was distinguished as croceo-salt.
According to the above formula the critical temperature is given by 8aA/54b, and as the critical temperature is approximately proportional to the boiling-point, both being estimated on the absolute scale of temperature, we may conclude that the larger value of b corresponds to the lower boilingpoint, and indeed the isomer corresponding to the left-hand formula boils at 74°, the other at 114°.
The remaining isomer, pivalic or trimethylacetic acid, (CH3)3C C02H, melts at 35° and boils at 163°.
Atropine is optically inactive; hyoscyamine, possibly a physical isomer, which yields atropine when heated to 108.6°, is laevorotatory.
The third isomer (sarcolactic acid) is found in meat extract (J.
The fourth isomer, formed by the action of Bacillus laevo-lacti on cane-sugar, resembles sarcolactic acid in every respect, except in its action on polarized light (see Stereoisomerism).